1.
Jmol
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Jmol is computer software for molecular modelling chemical structures in 3-dimensions. Jmol returns a 3D representation of a molecule that may be used as a teaching tool and it is written in the programming language Java, so it can run on the operating systems Windows, macOS, Linux, and Unix, if Java is installed. It is free and open-source software released under a GNU Lesser General Public License version 2.0, a standalone application and a software development kit exist that can be integrated into other Java applications, such as Bioclipse and Taverna. A popular feature is an applet that can be integrated into web pages to display molecules in a variety of ways, for example, molecules can be displayed as ball-and-stick models, space-filling models, ribbon diagrams, etc. Jmol supports a range of chemical file formats, including Protein Data Bank, Crystallographic Information File, MDL Molfile. There is also a JavaScript-only version, JSmol, that can be used on computers with no Java, the Jmol applet, among other abilities, offers an alternative to the Chime plug-in, which is no longer under active development. While Jmol has many features that Chime lacks, it does not claim to reproduce all Chime functions, most notably, Chime requires plug-in installation and Internet Explorer 6.0 or Firefox 2.0 on Microsoft Windows, or Netscape Communicator 4.8 on Mac OS9. Jmol requires Java installation and operates on a variety of platforms. For example, Jmol is fully functional in Mozilla Firefox, Internet Explorer, Opera, Google Chrome, fast and Scriptable Molecular Graphics in Web Browsers without Java3D
2.
ChemSpider
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ChemSpider is a database of chemicals. ChemSpider is owned by the Royal Society of Chemistry, the database contains information on more than 50 million molecules from over 500 data sources including, Each chemical is given a unique identifier, which forms part of a corresponding URL. This is an approach to develop an online chemistry database. The search can be used to widen or restrict already found results, structure searching on mobile devices can be done using free apps for iOS and for the Android. The ChemSpider database has been used in combination with text mining as the basis of document markup. The result is a system between chemistry documents and information look-up via ChemSpider into over 150 data sources. ChemSpider was acquired by the Royal Society of Chemistry in May,2009, prior to the acquisition by RSC, ChemSpider was controlled by a private corporation, ChemZoo Inc. The system was first launched in March 2007 in a release form. ChemSpider has expanded the generic support of a database to include support of the Wikipedia chemical structure collection via their WiChempedia implementation. A number of services are available online. SyntheticPages is an interactive database of synthetic chemistry procedures operated by the Royal Society of Chemistry. Users submit synthetic procedures which they have conducted themselves for publication on the site and these procedures may be original works, but they are more often based on literature reactions. Citations to the published procedure are made where appropriate. They are checked by an editor before posting. The pages do not undergo formal peer-review like a journal article. The comments are moderated by scientific editors. The intention is to collect practical experience of how to conduct useful chemical synthesis in the lab, while experimental methods published in an ordinary academic journal are listed formally and concisely, the procedures in ChemSpider SyntheticPages are given with more practical detail. Comments by submitters are included as well, other publications with comparable amounts of detail include Organic Syntheses and Inorganic Syntheses
3.
European Chemicals Agency
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ECHA is the driving force among regulatory authorities in implementing the EUs chemicals legislation. ECHA helps companies to comply with the legislation, advances the safe use of chemicals, provides information on chemicals and it is located in Helsinki, Finland. The Agency, headed by Executive Director Geert Dancet, started working on 1 June 2007, the REACH Regulation requires companies to provide information on the hazards, risks and safe use of chemical substances that they manufacture or import. Companies register this information with ECHA and it is freely available on their website. So far, thousands of the most hazardous and the most commonly used substances have been registered, the information is technical but gives detail on the impact of each chemical on people and the environment. This also gives European consumers the right to ask whether the goods they buy contain dangerous substances. The Classification, Labelling and Packaging Regulation introduces a globally harmonised system for classifying and labelling chemicals into the EU. This worldwide system makes it easier for workers and consumers to know the effects of chemicals, companies need to notify ECHA of the classification and labelling of their chemicals. So far, ECHA has received over 5 million notifications for more than 100000 substances, the information is freely available on their website. Consumers can check chemicals in the products they use, Biocidal products include, for example, insect repellents and disinfectants used in hospitals. The Biocidal Products Regulation ensures that there is information about these products so that consumers can use them safely. ECHA is responsible for implementing the regulation, the law on Prior Informed Consent sets guidelines for the export and import of hazardous chemicals. Through this mechanism, countries due to hazardous chemicals are informed in advance and have the possibility of rejecting their import. Substances that may have effects on human health and the environment are identified as Substances of Very High Concern 1. These are mainly substances which cause cancer, mutation or are toxic to reproduction as well as substances which persist in the body or the environment, other substances considered as SVHCs include, for example, endocrine disrupting chemicals. Companies manufacturing or importing articles containing these substances in a concentration above 0 and they are required to inform users about the presence of the substance and therefore how to use it safely. Consumers have the right to ask the retailer whether these substances are present in the products they buy, once a substance has been officially identified in the EU as being of very high concern, it will be added to a list. This list is available on ECHA’s website and shows consumers and industry which chemicals are identified as SVHCs, Substances placed on the Candidate List can then move to another list
4.
PubChem
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PubChem is a database of chemical molecules and their activities against biological assays. The system is maintained by the National Center for Biotechnology Information, a component of the National Library of Medicine, PubChem can be accessed for free through a web user interface. Millions of compound structures and descriptive datasets can be downloaded via FTP. PubChem contains substance descriptions and small molecules with fewer than 1000 atoms and 1000 bonds, more than 80 database vendors contribute to the growing PubChem database. PubChem consists of three dynamically growing primary databases, as of 28 January 2016, Compounds,82.6 million entries, contains pure and characterized chemical compounds. Substances,198 million entries, contains also mixtures, extracts, complexes, bioAssay, bioactivity results from 1.1 million high-throughput screening programs with several million values. PubChem contains its own online molecule editor with SMILES/SMARTS and InChI support that allows the import and export of all common chemical file formats to search for structures and fragments. In the text search form the database fields can be searched by adding the name in square brackets to the search term. A numeric range is represented by two separated by a colon. The search terms and field names are case-insensitive, parentheses and the logical operators AND, OR, and NOT can be used. AND is assumed if no operator is used, example,0,5000,50,10 -5,5 PubChem was released in 2004. The American Chemical Society has raised concerns about the publicly supported PubChem database and they have a strong interest in the issue since the Chemical Abstracts Service generates a large percentage of the societys revenue. To advocate their position against the PubChem database, ACS has actively lobbied the US Congress, soon after PubChems creation, the American Chemical Society lobbied U. S. Congress to restrict the operation of PubChem, which they asserted competes with their Chemical Abstracts Service
5.
International Chemical Identifier
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Initially developed by IUPAC and NIST from 2000 to 2005, the format and algorithms are non-proprietary. The continuing development of the standard has supported since 2010 by the not-for-profit InChI Trust. The current version is 1.04 and was released in September 2011, prior to 1.04, the software was freely available under the open source LGPL license, but it now uses a custom license called IUPAC-InChI Trust License. Not all layers have to be provided, for instance, the layer can be omitted if that type of information is not relevant to the particular application. InChIs can thus be seen as akin to a general and extremely formalized version of IUPAC names and they can express more information than the simpler SMILES notation and differ in that every structure has a unique InChI string, which is important in database applications. Information about the 3-dimensional coordinates of atoms is not represented in InChI, the InChI algorithm converts input structural information into a unique InChI identifier in a three-step process, normalization, canonicalization, and serialization. The InChIKey, sometimes referred to as a hashed InChI, is a fixed length condensed digital representation of the InChI that is not human-understandable. The InChIKey specification was released in September 2007 in order to facilitate web searches for chemical compounds and it should be noted that, unlike the InChI, the InChIKey is not unique, though collisions can be calculated to be very rare, they happen. In January 2009 the final 1.02 version of the InChI software was released and this provided a means to generate so called standard InChI, which does not allow for user selectable options in dealing with the stereochemistry and tautomeric layers of the InChI string. The standard InChIKey is then the hashed version of the standard InChI string, the standard InChI will simplify comparison of InChI strings and keys generated by different groups, and subsequently accessed via diverse sources such as databases and web resources. Every InChI starts with the string InChI= followed by the version number and this is followed by the letter S for standard InChIs. The remaining information is structured as a sequence of layers and sub-layers, the layers and sub-layers are separated by the delimiter / and start with a characteristic prefix letter. The six layers with important sublayers are, Main layer Chemical formula and this is the only sublayer that must occur in every InChI. The atoms in the formula are numbered in sequence, this sublayer describes which atoms are connected by bonds to which other ones. Describes how many hydrogen atoms are connected to each of the other atoms, the condensed,27 character standard InChIKey is a hashed version of the full standard InChI, designed to allow for easy web searches of chemical compounds. Most chemical structures on the Web up to 2007 have been represented as GIF files, the full InChI turned out to be too lengthy for easy searching, and therefore the InChIKey was developed. With all databases currently having below 50 million structures, such duplication appears unlikely at present, a recent study more extensively studies the collision rate finding that the experimental collision rate is in agreement with the theoretical expectations. Example, Morphine has the structure shown on the right, as the InChI cannot be reconstructed from the InChIKey, an InChIKey always needs to be linked to the original InChI to get back to the original structure
6.
Simplified molecular-input line-entry system
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The simplified molecular-input line-entry system is a specification in form of a line notation for describing the structure of chemical species using short ASCII strings. SMILES strings can be imported by most molecule editors for conversion back into two-dimensional drawings or three-dimensional models of the molecules, the original SMILES specification was initiated in the 1980s. It has since modified and extended. In 2007, a standard called OpenSMILES was developed in the open-source chemistry community. Other linear notations include the Wiswesser Line Notation, ROSDAL and SLN, the original SMILES specification was initiated by David Weininger at the USEPA Mid-Continent Ecology Division Laboratory in Duluth in the 1980s. The Environmental Protection Agency funded the project to develop SMILES. It has since modified and extended by others, most notably by Daylight Chemical Information Systems. In 2007, a standard called OpenSMILES was developed by the Blue Obelisk open-source chemistry community. Other linear notations include the Wiswesser Line Notation, ROSDAL and SLN, in July 2006, the IUPAC introduced the InChI as a standard for formula representation. SMILES is generally considered to have the advantage of being slightly more human-readable than InChI, the term SMILES refers to a line notation for encoding molecular structures and specific instances should strictly be called SMILES strings. However, the term SMILES is also used to refer to both a single SMILES string and a number of SMILES strings, the exact meaning is usually apparent from the context. The terms canonical and isomeric can lead to confusion when applied to SMILES. The terms describe different attributes of SMILES strings and are not mutually exclusive, typically, a number of equally valid SMILES strings can be written for a molecule. For example, CCO, OCC and CC all specify the structure of ethanol, algorithms have been developed to generate the same SMILES string for a given molecule, of the many possible strings, these algorithms choose only one of them. This SMILES is unique for each structure, although dependent on the algorithm used to generate it. These algorithms first convert the SMILES to a representation of the molecular structure. A common application of canonical SMILES is indexing and ensuring uniqueness of molecules in a database, there is currently no systematic comparison across commercial software to test if such flaws exist in those packages. SMILES notation allows the specification of configuration at tetrahedral centers, and these are structural features that cannot be specified by connectivity alone and SMILES which encode this information are termed isomeric SMILES
7.
Chemical formula
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These are limited to a single typographic line of symbols, which may include subscripts and superscripts. A chemical formula is not a name, and it contains no words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulas can fully specify the structure of only the simplest of molecules and chemical substances, the simplest types of chemical formulas are called empirical formulas, which use letters and numbers indicating the numerical proportions of atoms of each type. Molecular formulas indicate the numbers of each type of atom in a molecule. For example, the formula for glucose is CH2O, while its molecular formula is C6H12O6. This is possible if the relevant bonding is easy to show in one dimension, an example is the condensed molecular/chemical formula for ethanol, which is CH3-CH2-OH or CH3CH2OH. For reasons of structural complexity, there is no condensed chemical formula that specifies glucose, chemical formulas may be used in chemical equations to describe chemical reactions and other chemical transformations, such as the dissolving of ionic compounds into solution. A chemical formula identifies each constituent element by its chemical symbol, in empirical formulas, these proportions begin with a key element and then assign numbers of atoms of the other elements in the compound, as ratios to the key element. For molecular compounds, these numbers can all be expressed as whole numbers. For example, the formula of ethanol may be written C2H6O because the molecules of ethanol all contain two carbon atoms, six hydrogen atoms, and one oxygen atom. Some types of compounds, however, cannot be written with entirely whole-number empirical formulas. An example is boron carbide, whose formula of CBn is a variable non-whole number ratio with n ranging from over 4 to more than 6.5. When the chemical compound of the consists of simple molecules. These types of formulas are known as molecular formulas and condensed formulas. A molecular formula enumerates the number of atoms to reflect those in the molecule, so that the formula for glucose is C6H12O6 rather than the glucose empirical formula. However, except for very simple substances, molecular chemical formulas lack needed structural information, for simple molecules, a condensed formula is a type of chemical formula that may fully imply a correct structural formula. For example, ethanol may be represented by the chemical formula CH3CH2OH
8.
Density
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The density, or more precisely, the volumetric mass density, of a substance is its mass per unit volume. The symbol most often used for density is ρ, although the Latin letter D can also be used. Mathematically, density is defined as mass divided by volume, ρ = m V, where ρ is the density, m is the mass, and V is the volume. In some cases, density is defined as its weight per unit volume. For a pure substance the density has the numerical value as its mass concentration. Different materials usually have different densities, and density may be relevant to buoyancy, purity, osmium and iridium are the densest known elements at standard conditions for temperature and pressure but certain chemical compounds may be denser. Thus a relative density less than one means that the floats in water. The density of a material varies with temperature and pressure and this variation is typically small for solids and liquids but much greater for gases. Increasing the pressure on an object decreases the volume of the object, increasing the temperature of a substance decreases its density by increasing its volume. In most materials, heating the bottom of a results in convection of the heat from the bottom to the top. This causes it to rise relative to more dense unheated material, the reciprocal of the density of a substance is occasionally called its specific volume, a term sometimes used in thermodynamics. Density is a property in that increasing the amount of a substance does not increase its density. Archimedes knew that the irregularly shaped wreath could be crushed into a cube whose volume could be calculated easily and compared with the mass, upon this discovery, he leapt from his bath and ran naked through the streets shouting, Eureka. As a result, the term eureka entered common parlance and is used today to indicate a moment of enlightenment, the story first appeared in written form in Vitruvius books of architecture, two centuries after it supposedly took place. Some scholars have doubted the accuracy of this tale, saying among other things that the method would have required precise measurements that would have been difficult to make at the time, from the equation for density, mass density has units of mass divided by volume. As there are units of mass and volume covering many different magnitudes there are a large number of units for mass density in use. The SI unit of kilogram per metre and the cgs unit of gram per cubic centimetre are probably the most commonly used units for density.1,000 kg/m3 equals 1 g/cm3. In industry, other larger or smaller units of mass and or volume are often more practical, see below for a list of some of the most common units of density
9.
Boiling point
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The boiling point of a substance is the temperature at which the vapor pressure of the liquid equals the pressure surrounding the liquid and the liquid changes into a vapor. The boiling point of a liquid varies depending upon the environmental pressure. A liquid in a vacuum has a lower boiling point than when that liquid is at atmospheric pressure. A liquid at high pressure has a boiling point than when that liquid is at atmospheric pressure. For a given pressure, different liquids boil at different temperatures, for example, water boils at 100 °C at sea level, but at 93.4 °C at 2,000 metres altitude. The normal boiling point of a liquid is the case in which the vapor pressure of the liquid equals the defined atmospheric pressure at sea level,1 atmosphere. At that temperature, the pressure of the liquid becomes sufficient to overcome atmospheric pressure. The standard boiling point has been defined by IUPAC since 1982 as the temperature at which boiling occurs under a pressure of 1 bar, the heat of vaporization is the energy required to transform a given quantity of a substance from a liquid into a gas at a given pressure. Liquids may change to a vapor at temperatures below their boiling points through the process of evaporation, evaporation is a surface phenomenon in which molecules located near the liquids edge, not contained by enough liquid pressure on that side, escape into the surroundings as vapor. On the other hand, boiling is a process in which molecules anywhere in the liquid escape, a saturated liquid contains as much thermal energy as it can without boiling. The saturation temperature is the temperature for a corresponding saturation pressure at which a liquid boils into its vapor phase, the liquid can be said to be saturated with thermal energy. Any addition of energy results in a phase transition. If the pressure in a system remains constant, a vapor at saturation temperature will begin to condense into its liquid phase as thermal energy is removed, similarly, a liquid at saturation temperature and pressure will boil into its vapor phase as additional thermal energy is applied. The boiling point corresponds to the temperature at which the pressure of the liquid equals the surrounding environmental pressure. Thus, the point is dependent on the pressure. Boiling points may be published with respect to the NIST, USA standard pressure of 101.325 kPa, at higher elevations, where the atmospheric pressure is much lower, the boiling point is also lower. The boiling point increases with increased pressure up to the critical point, the boiling point cannot be increased beyond the critical point. Likewise, the point decreases with decreasing pressure until the triple point is reached
10.
Acrolein
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Acrolein is the simplest unsaturated aldehyde. It is a liquid with a piercing, disagreeable, acrid smell. The smell of burnt fat is caused by glycerol in the burning fat breaking down into acrolein and it is produced industrially from propylene and mainly used as a biocide and a building block to other chemical compounds, such as the amino acid methionine. Acrolein is prepared industrially by oxidation of propene, additionally, all acrylic acid is produced via the transient formation of acrolein. The main challenge is in fact the competing overoxidation to this acid, propane represents a promising but challenging feedstock for the synthesis of acrolein. The dehydration of glycerol has been demonstrated but has not proven competitive with the route from petrochemicals, acrolein is a relatively electrophilic compound and a reactive one, hence its high toxicity. It is a good Michael acceptor, hence its useful reaction with thiols and it forms acetals readily, a prominent one being the spirocycle derived from pentaerythritol, diallylidene pentaerythritol. Acrolein participates in many Diels-Alder reactions, even with itself, via Diels-Alder reactions, it is a precursor to some commercial fragrances, including lyral, norbornene-2-carboxaldehyde, and myrac aldehyde. Acrolein is mainly used as a herbicide to control submersed and floating weeds, as well as algae. It is used at a level of 10 ppm in irrigation, in the oil and gas industry, it is used as a biocide in drilling waters, as well as a scavenger for hydrogen sulfide and mercaptans. A number of compounds are made from acrolein, exploiting its bifunctionality. The amino acid methionine is produced by addition of methanethiol followed by the Strecker synthesis, acrolein condenses with acetaldehyde and amines to give methylpyridines. It is also thought to be an intermediate in the Skraup synthesis of quinolines, acrolein will polymerize in the presence of oxygen and in water at concentrations above 22%. The color and texture of the polymer depends on the conditions, over time, it will polymerize with itself to form a clear, yellow solid. In water, it form a hard, porous plastic. Acrolein is sometimes used as a fixative in preparation of specimens for electron microscopy. Acrolein is toxic and is an irritant for the skin, eyes. The main metabolic pathway for acrolein is the alkylation of glutathione, the WHO suggests a tolerable oral acrolein intake of 7.5 μg/day per kilogram of body weight
11.
Crotonaldehyde
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Crotonaldehyde is a chemical compound with the formula CH3CH=CHCHO. The compound is sold as a mixture of the E- and Z-isomers. This lachrymatory liquid is soluble in water and miscible in organic solvents. As an unsaturated aldehyde, crotonaldehyde is an intermediate in organic synthesis. It occurs in a variety of foodstuffs, e. g. soybean oils, crotonaldehyde is produced by the aldol condensation of acetaldehyde,2 CH3CHO → CH3CH=CHCHO + H2O Its main application is as a precursor to fine chemicals. Sorbic acid, a preservative, and trimethylhydroquinone, a precursor to the vitamin E, are prepared from crotonaldehyde. Other derivatives include crotonic acid and 3-methoxybutanol, crotonaldehyde is a multifunctional molecule that exhibits diverse reactivity. It is an excellent prochiral dienophile, addition of methylmagnesium chloride affords 3-penten-2-ol. It is listed as a hazardous substance as defined by the U. S. Emergency Planning and Community Right-to-Know Act and it is used to make preservatives. Crotyl Crotonic acid Crotyl alcohol Methacrolein Hazardous Substance Fact Sheet CDC - NIOSH Pocket Guide to Chemical Hazards
12.
Aroma compound
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An aroma-compound, also known as an odorant, aroma, fragrance, or flavor, is a chemical compound that has a smell or odor. A chemical-compound has a smell or odor when it is volatile to be transported to the olfactory system in the upper-part of the nose. Generally molecules meeting this specification have molecular weights of <300, flavors affect both the sense of taste and smell, whereas fragrances affect only smell. Flavors tend to be occurring, and fragrances tend to be synthetic. Aroma-compounds can be found in food, wine, spices, floral scent, perfumes, fragrance oils, for example, many form biochemically during the ripening of fruits and other crops. In wines, most form as byproducts of fermentation, an odorizer may add an odorant to a dangerous odorless substance, like propane, natural gas, or hydrogen, as a safety measure. Note, Carvone, depending on its chirality, offers two different smells, furaneol 1-Hexanol cis-3-Hexen-1-ol Menthol High concentrations of aldehydes tend to be very pungent and overwhelming, but low concentrations can evoke a wide range of aromas. Acetaldehyde Hexanal cis-3-Hexenal Furfural Hexyl cinnamaldehyde Isovaleraldehyde – nutty, fruity, cocoa-like Anisic aldehyde – floral, sweet and it is a crucial component of chocolate, vanilla, strawberry, raspberry, apricot, and others. Its smell is so potent it can be detected several hundred meters downwind mere seconds after a container is opened, butane-1-thiol, commonly called normal-butyl mercaptan is a chemical-intermediate. Olfactory-receptors are cell-membrane receptors on the surface of neurons in the olfactory system that detect air-borne. In mammals, olfactory-receptors are expressed on the surface of the epithelium in the nasal cavity. In 2005–06, fragrance-mix was the third-most-prevalent allergen in patch tests, Fragrance was voted Allergen of the Year in 2007 by the American Contact Dermatitis Society. The composition of fragrances is usually not disclosed in the label of products, hiding the actual chemicals of the formula, the EPA, however, does not conduct independent-safety testing but relies on data provided by the manufacturer. In 2010 the International Fragrance Association published a list of 3,059 chemicals used in 2011 based on a voluntary-survey of its members and it was estimated to represent about 90% of the worlds production-volume of fragrances
13.
Odor
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An odor or odour or fragrance is caused by one or more volatilized chemical compounds, generally at a very low concentration, that humans or other animals perceive by the sense of olfaction. Odors are also commonly called scents, which can refer to both pleasant and unpleasant odors, the terms fragrance and aroma are used primarily by the food and cosmetic industry to describe a pleasant odor, and are sometimes used to refer to perfumes, and to describe floral scent. In contrast, malodor, stench, reek, and stink are used specifically to describe unpleasant odor, the term smell is used for both pleasant and unpleasant odors. In the United Kingdom, odour refers to scents in general, the sense of smell gives rise to the perception of odors, mediated by the olfactory nerve. The olfactory receptor cells are present in the olfactory epithelium. There are millions of olfactory receptor neurons that act as sensory signaling cells, each neuron has cilia in direct contact with air. The olfactory nerve is considered the smell mediator, the axon connects the brain to the external air, odorous molecules act as a chemical stimulus. Molecules bind to receptor proteins extended from cilia, initiating an electric signal, thus, by using a chemical that binds to copper in the mouse nose, so that copper wasn’t available to the receptors, the authors showed that the mice couldnt detect the thiols. However, these also found that MOR244-3 lacks the specific metal ion binding site suggested by Suslick. When the signal reaches a threshold, the fires, sending a signal traveling along the axon to the olfactory bulb. Interpretation of the begins, relating the smell to past experiences. The olfactory bulb acts as a station connecting the nose to the olfactory cortex in the brain. Olfactory information is processed and projected through a pathway to the central nervous system. Odor sensation usually depends on the concentration available to the olfactory receptors, the olfactory system does not interpret a single compound, but instead the whole odorous mix, not necessarily corresponding to concentration or intensity of any single constituent. The widest range of odors consists of compounds, although some simple compounds not containing carbon, such as hydrogen sulfide. The perception of an effect is a two-step process. First, there is the part, the detection of stimuli by receptors in the nose. The stimuli are processed by the region of the brain which is responsible for olfaction
14.
Poaceae
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Poaceae or Gramineae is a large and nearly ubiquitous family of monocotyledonous flowering plants known as grasses. Poaceae includes the cereal grasses, bamboos and the grasses of natural grassland and cultivated lawns, Grasses have stems that are hollow except at the nodes and narrow alternate leaves borne in two ranks. The lower part of each leaf encloses the stem, forming a leaf-sheath, with ca 780 genera and around 12,000 species, Poaceae are the fifth-largest plant family, following the Asteraceae, Orchidaceae, Fabaceae and Rubiaceae. Grasslands such as savannah and prairie grasses are dominant are estimated to constitute 40. 5% of the land area of the Earth, excluding Greenland. Grasses are also an important part of the vegetation in many habitats, including wetlands, forests. Though commonly called grasses, seagrasses, rushes, and sedges fall outside this family, the rushes and sedges are related to the Poaceae, being members of the order Poales, but the seagrasses are members of order Alismatales. The name Poaceae was given by John Hendley Barnhart in 1895, based on the tribe Poeae described in 1814 by Robert Brown, the term is derived from the Ancient Greek πόα. Grasses include some of the most versatile plant life-forms, a cladogram shows subfamilies and approximate species numbers in brackets, Before 2005, fossil findings indicated that grasses evolved around 55 million years ago. Recent findings of grass-like phytoliths in Cretaceous dinosaur coprolites have pushed this back to 66 million years ago. In 2011, revised dating of the origins of the rice tribe Oryzeae suggested a date as early as 107 to 129 Mya, a multituberculate mammal with grass-eating adaptations seems to suggest that grasses were already around at 120 mya. This separation occurred within the short time span of about 4 million years. Grass leaves are always alternate and distichous, and have parallel veins. Each leaf is differentiated into a lower sheath hugging the stem, the leaf blades of many grasses are hardened with silica phytoliths, which discourage grazing animals, some, such as sword grass, are sharp enough to cut human skin. A membranous appendage or fringe of hairs called the ligule lies at the junction between sheath and blade, preventing water or insects from penetrating into the sheath, flowers of Poaceae are characteristically arranged in spikelets, each having one or more florets. The spikelets are further grouped into panicles or spikes, the part of the spikelet that bears the florets is called the rachilla. A spikelet consists of two bracts at the base, called glumes, followed by one or more florets, a floret consists of the flower surrounded by two bracts, one external—the lemma—and one internal—the palea. The flowers are usually hermaphroditic—maize being an important exception—and anemophilous or wind-pollinated, the perianth is reduced to two scales, called lodicules, that expand and contract to spread the lemma and palea, these are generally interpreted to be modified sepals. This complex structure can be seen in the image on the right, the fruit of grasses is a caryopsis, in which the seed coat is fused to the fruit wall
15.
Leaf
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A leaf is an organ of a vascular plant and is the principal lateral appendage of the stem. The leaves and stem together form the shoot, Leaves are collectively referred to as foliage, as in autumn foliage. Although leaves can be seen in different shapes, sizes and textures, typically a leaf is a thin, dorsiventrally flattened organ, borne above ground. Most leaves have distinctive upper surface and lower surface that differ in colour, hairiness, broad, flat leaves with complex venation are known as megaphylls and the species that bear them, the majority, as broad-leaved or megaphyllous plants. In others, such as the clubmosses, with different evolutionary origins, some leaves, such as bulb scales are not above ground, and in many aquatic species the leaves are submerged in water. Succulent plants often have thick juicy leaves, but some leaves are without major photosynthetic function and may be dead at maturity, as in some cataphylls, furthermore, several kinds of leaf-like structures found in vascular plants are not totally homologous with them. Examples include flattened plant stems called phylloclades and cladodes, and flattened leaf stems called phyllodes which differ from both in their structure and origin. Many structures of plants, such as the phyllids of mosses and liverworts and even of some foliose lichens. Leaves are the most important organs of most vascular plants and these are then further processed by chemical synthesis into more complex organic molecules such as cellulose, the basic structural material in plant cell walls. The plant must therefore bring these three together in the leaf for photosynthesis to take place. Once sugar has been synthesized, it needs to be transported to areas of growth such as the plant shoots and roots. Vascular plants transport sucrose in a tissue called the phloem. The phloem and xylem are parallel to each other but the transport of materials is usually in opposite directions. Within the leaf these vascular systems branch to form veins which supply as much as the leaf as possible and they are arranged on the plant so as to expose their surfaces to light as efficiently as possible without shading each other, but there are many exceptions and complications. For instance plants adapted to windy conditions may have pendent leaves, such as in many willows, the flat, or laminar, shape also maximises thermal contact with the surrounding air, promoting cooling. Functionally, in addition to photosynthesis the leaf is the site of transpiration and guttation. Many gymnosperms have thin needle-like or scale-like leaves that can be advantageous in cold climates with frequent snow and these are interpreted as reduced from megaphyllous leaves of their Devonian ancestors. For xerophytes the major constraint is not light flux or intensity, some window plants such as Fenestraria species and some Haworthia species such as Haworthia tesselata and Haworthia truncata are examples of xerophytes. and Bulbine mesembryanthemoides
16.
Tomato
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The tomato is the edible fruit of Solanum lycopersicum, commonly known as a tomato plant, which belongs to the nightshade family, Solanaceae. The species originated in Central and South America, the Nahuatl word tomatl gave rise to the Spanish word tomate, from which the English word tomato originates. Numerous varieties of tomato are widely grown in temperate climates across the world, with greenhouses allowing its production throughout the year, the plants typically grow to 1–3 meters in height and have a weak stem that often sprawls over the ground and vines over other plants. It is a perennial in its habitat, and grown as an annual in temperate climates. An average common tomato weighs approximately 100 grams and its use as a food originated in Mexico, and spread throughout the world following the Spanish colonization of the Americas. Tomato is consumed in diverse ways, including raw, as an ingredient in dishes, sauces, salads. While tomatoes are botanically fruits, they are considered culinary vegetables. The word tomato comes from the Spanish tomate, which in turn comes from the Nahuatl word tomatl and it first appeared in print in 1595. The native Mexican tomatillo is tomate, meaning fat water or fat thing), when Aztecs started to cultivate the Andean fruit, bigger and red, they called the new species xitomatl. It first appeared in print in 1595, the scientific species epithet lycopersicum means wolf peach, and comes from German werewolf myths. The Italian word, pomodoro was borrowed into Polish, and via Russian, the usual pronunciations of tomato are /təˈmeɪtoʊ/ and /təˈmɑːtoʊ/. The words dual pronunciations were immortalized in Ira and George Gershwins 1937 song Lets Call the Whole Thing Off and have become a symbol for nitpicking pronunciation disputes. In this capacity, it has become an American and British slang term. Or Its all the same to me, botanically, a tomato is a fruit, a berry, consisting of the ovary, together with its seeds, of a flowering plant. However, the tomato has a lower sugar content than other edible fruits. Typically served as part of a salad or main course of a meal, rather than at dessert, it is, in the US, considered a culinary vegetable. One exception is that tomatoes are treated as a fruit in home canning practices, they are acidic enough to process in a water bath rather than a pressure cooker as vegetables require. Tomatoes are not the food source with this ambiguity, bell peppers, cucumbers, green beans, eggplants, avocados
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Plant
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Plants are mainly multicellular, predominantly photosynthetic eukaryotes of the kingdom Plantae. The term is generally limited to the green plants, which form an unranked clade Viridiplantae. This includes the plants, conifers and other gymnosperms, ferns, clubmosses, hornworts, liverworts, mosses and the green algae. Green plants have cell walls containing cellulose and obtain most of their energy from sunlight via photosynthesis by primary chloroplasts and their chloroplasts contain chlorophylls a and b, which gives them their green color. Some plants are parasitic and have lost the ability to produce amounts of chlorophyll or to photosynthesize. Plants are characterized by sexual reproduction and alternation of generations, although reproduction is also common. There are about 300–315 thousand species of plants, of which the great majority, green plants provide most of the worlds molecular oxygen and are the basis of most of Earths ecologies, especially on land. Plants that produce grains, fruits and vegetables form humankinds basic foodstuffs, Plants play many roles in culture. They are used as ornaments and, until recently and in variety, they have served as the source of most medicines. The scientific study of plants is known as botany, a branch of biology, Plants are one of the two groups into which all living things were traditionally divided, the other is animals. The division goes back at least as far as Aristotle, who distinguished between plants, which generally do not move, and animals, which often are mobile to catch their food. Much later, when Linnaeus created the basis of the system of scientific classification. Since then, it has become clear that the plant kingdom as originally defined included several unrelated groups, however, these organisms are still often considered plants, particularly in popular contexts. When the name Plantae or plant is applied to a group of organisms or taxon. The evolutionary history of plants is not yet settled. Those which have been called plants are in bold, the way in which the groups of green algae are combined and named varies considerably between authors. Algae comprise several different groups of organisms which produce energy through photosynthesis, most conspicuous among the algae are the seaweeds, multicellular algae that may roughly resemble land plants, but are classified among the brown, red and green algae. Each of these groups also includes various microscopic and single-celled organisms
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Predation
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In an ecosystem, predation is a biological interaction where a predator feeds on its prey. Predators may or may not kill their prey prior to feeding on it, but the act of predation often results in the death of the prey, thus predation is often, though not always, carnivory. Other categories of consumption are herbivory, fungivory, and detritivory, all of these are consumer-resource systems. It can often be difficult to separate various types of feeding behaviors. For example, some parasites prey on their host and then lay their eggs on it, for their offspring to feed on it while it continues to live, the key characteristic of predation is the predators direct impact on the prey population. Selective pressures imposed on one another leads to an evolutionary arms race between prey and predator, resulting in various antipredator adaptations. Ways of classifying predation include grouping by trophic level or diet, by specialization, Predators can be classified by their interactions with their prey. Two factors are considered here, how close the predator and prey are, and whether the prey is killed by the predator. A true predator is one that kills and eats another living thing, Predators may hunt actively for prey in pursuit predation, or sit and wait for prey to approach within striking distance, as in ambush predators. Some predation entails venom that subdues a prey before the predator ingests it, as in the box jellyfish, or disables it, in some cases, the venom contributes to the digestion of the prey, as in rattlesnakes and some spiders. In contrast, baleen whales eat millions of microscopic plankton at once, seed and egg predation are true predation, as seeds and eggs are potential organisms. Predators need not eat prey entirely, for example, some predators cannot digest bones, some may eat only part of an organism, but still consistently cause its death. Grazing organisms do not often kill their prey, while some herbivores like zooplankton live on unicellular phytoplankton and therefore, by the individualized nature of the organism, kill their prey, many others only eat a small part of the plant. Grazing livestock may pull some grass out at the roots, but most is simply grazed upon, kelp is frequently grazed in subtidal kelp forests, but regrows at the base of the blade continuously to cope with browsing pressure. Animals may also be grazed upon, female mosquitos land on hosts briefly to gain sufficient proteins for the development of their offspring, starfish may be grazed on, being capable of regenerating lost arms. Parasites can at times be difficult to distinguish from grazers and their feeding behavior is similar in many ways, however they are noted for their close association with their host species. This close living arrangement may be described by the symbiosis, living together. Parasitic organisms range from the mistletoe, a parasitic plant
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Insect
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Insects are a class of hexapod invertebrates within the arthropod phylum that have a chitinous exoskeleton, a three-part body, three pairs of jointed legs, compound eyes and one pair of antennae. They are the most diverse group of animals on the planet, including more than a million described species, the number of extant species is estimated at between six and ten million, and potentially represent over 90% of the differing animal life forms on Earth. Insects may be found in all environments, although only a small number of species reside in the oceans. The life cycles of insects vary but most hatch from eggs, insect growth is constrained by the inelastic exoskeleton and development involves a series of molts. The immature stages can differ from the adults in structure, habit and habitat, Insects that undergo 3-stage metamorphosis lack a pupal stage and adults develop through a series of nymphal stages. The higher level relationship of the Hexapoda is unclear, fossilized insects of enormous size have been found from the Paleozoic Era, including giant dragonflies with wingspans of 55 to 70 cm. The most diverse insect groups appear to have coevolved with flowering plants, adult insects typically move about by walking, flying or sometimes swimming. As it allows for rapid yet stable movement, many insects adopt a tripedal gait in which they walk with their legs touching the ground in alternating triangles, Insects are the only invertebrates to have evolved flight. Many insects spend at least part of their lives under water, with adaptations that include gills. Some species, such as water striders, are capable of walking on the surface of water, Insects are mostly solitary, but some, such as certain bees, ants and termites, are social and live in large, well-organized colonies. Some insects, such as earwigs, show maternal care, guarding their eggs, Insects can communicate with each other in a variety of ways. Male moths can sense the pheromones of female moths over great distances, other species communicate with sounds, crickets stridulate, or rub their wings together, to attract a mate and repel other males. Lampyridae in the beetle order communicate with light, humans regard certain insects as pests, and attempt to control them using insecticides and a host of other techniques. Some insects damage crops by feeding on sap, leaves or fruits, a few parasitic species are pathogenic. Some insects perform complex ecological roles, blow-flies, for example, help consume carrion, Many other insects are considered ecologically beneficial as predators and a few provide direct economic benefit. Silkworms and bees have been used extensively by humans for the production of silk and honey, in some cultures, people eat the larvae or adults of certain insects. Insect first appears documented in English in 1601 in Hollands translation of Pliny, translations of Aristotles term also form the usual word for insect in Welsh, Serbo-Croatian, Russian, etc. The evolutionary relationship of insects to other animal groups remains unclear, in the Pancrustacea theory, insects, together with Entognatha, Remipedia, and Cephalocarida, make up a natural clade labeled Miracrustacea
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Pheromone
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A pheromone is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting outside the body of the individual to impact the behavior of the receiving individuals. There are alarm pheromones, food trail pheromones, sex pheromones, Pheromones are used from basic unicellular prokaryotes to complex multicellular eukaryotes. Their use among insects has been well documented. In addition, some vertebrates, plants and ciliates communicate by using pheromones, the portmanteau word pheromone was coined by Peter Karlson and Martin Lüscher in 1959, based on the Greek φερω pheroo and ὁρμων hormon. Pheromones are also classified as ecto-hormones. For this reason, bacteria are too small to use pheromones as sex attractants on an individual basis, however, they do use them to determine the local population density of similar organisms and control behaviors that take more time to execute. Aggregation pheromones function in mate selection, overcoming host resistance by mass attack, a group of individuals at one location is referred to as an aggregation, whether consisting of one sex or both sexes. Most sex pheromones are produced by the females, only a percentage of sex attractants are produced by males. Aggregation pheromones have been found in members of the Coleoptera, Diptera, Hemiptera, Dictyoptera, aggregation pheromones are among the most ecologically selective pest suppression methods. They are nontoxic and effective at low concentrations. Some species release a volatile substance when attacked by a predator that can trigger flight or aggression in members of the same species, for example, Vespula squamosa use alarm pheromones to alert others to a threat. In Polistes exclamans, alarm pheromones are used as an alert to incoming predators. Pheromones also exist in plants, Certain plants emit alarm pheromones when grazed upon and these tannins make the plants less appetizing for the herbivore. Epideictic pheromones are different from territory pheromones, when it comes to insects, releaser pheromones are pheromones that cause an alteration in the behavior of the recipient. For example, some organisms use powerful attractant molecules to attract mates from a distance of two miles or more, in general, this type of pheromone elicits a rapid response, but is quickly degraded. In contrast, a primer pheromone has an onset and a longer duration. For example, rabbit release mammary pheromones that trigger immediate nursing behavior by their babies, signal pheromones cause short-term changes, such as the neurotransmitter release that activates a response
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Aldehyde
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The group—without R—is the aldehyde group, also known as the formyl group. Aldehydes are common in organic chemistry, Aldehydes feature an sp2-hybridized, planar carbon center that is connected by a double bond to oxygen and a single bond to hydrogen. The C–H bond is not ordinarily acidic, because of resonance stabilization of the conjugate base, an α-hydrogen in an aldehyde is far more acidic, with a pKa near 15, compared to the acidity of a typical alkane. This acidification is attributed to the quality of the formyl center and the fact that the conjugate base. Related to, the group is somewhat polar. Aldehydes can exist in either the keto or the enol tautomer, keto-enol tautomerism is catalyzed by either acid or base. Usually the enol is the minority tautomer, but it is more reactive, the common names for aldehydes do not strictly follow official guidelines, such as those recommended by IUPAC, but these rules are useful. IUPAC prescribes the following nomenclature for aldehydes, Acyclic aliphatic aldehydes are named as derivatives of the longest carbon chain containing the aldehyde group, thus, HCHO is named as a derivative of methane, and CH3CH2CH2CHO is named as a derivative of butane. The name is formed by changing the suffix -e of the parent alkane to -al, so that HCHO is named methanal, in other cases, such as when a -CHO group is attached to a ring, the suffix -carbaldehyde may be used. Thus, C6H11CHO is known as cyclohexanecarbaldehyde, if the presence of another functional group demands the use of a suffix, the aldehyde group is named with the prefix formyl-. This prefix is preferred to methanoyl-, the word aldehyde was coined by Justus von Liebig as a contraction of the Latin alcohol dehydrogenatus. In the past, aldehydes were sometimes named after the corresponding alcohols, for example, the term formyl group is derived from the Latin word formica ant. This word can be recognized in the simplest aldehyde, formaldehyde, Aldehydes have properties that are diverse and that depend on the remainder of the molecule. Smaller aldehydes are more soluble in water, formaldehyde and acetaldehyde completely so, the volatile aldehydes have pungent odors. Aldehydes degrade in air via the process of autoxidation, the two aldehydes of greatest importance in industry, formaldehyde and acetaldehyde, have complicated behavior because of their tendency to oligomerize or polymerize. They also tend to hydrate, forming the geminal diol, the oligomers/polymers and the hydrates exist in equilibrium with the parent aldehyde. Aldehydes are readily identified by spectroscopic methods, using IR spectroscopy, they display a strong νCO band near 1700 cm−1. In their 1H NMR spectra, the formyl hydrogen center absorbs near δH =9 and this signal shows the characteristic coupling to any protons on the alpha carbon
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Isomerization
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In chemistry isomerization is the process by which one molecule is transformed into another molecule which has exactly the same atoms, but the atoms have a different arrangement e. g. A-B-C → B-A-C. In some molecules and under conditions, isomerization occurs spontaneously. When the isomerization occurs intramolecularly it is considered a rearrangement reaction, an example of an organometallic isomerization is the production of decaphenylferrocene, from its linkage isomer. Isomerization in hydrocarbon cracking is usually employed in chemistry, where fuels, such as diesel or pentane. The straight- and branched-chain isomers in the mixture then have to be separated. Another industrial process is the isomerisation of n-butane into isobutane, trans-cis isomerism is where, in certain compounds, an interconversion of cis and trans isomers can be observed. For instance, with acid and with azobenzene, often by photoisomerization. g. Bullvalene, and valence isomerization, the isomerization of molecules which involve structural changes resulting only from a relocation of single and double bonds, if a dynamic equilibrium is established between the two isomers it is also referred to as valence tautomerism. In a cycloisomerization a cyclic compound is formed, isomerization reactions can also be found with specific aromatic hydrocarbons. The energy difference between two isomers is called isomerization energy
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Conjugated system
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Lone pairs, radicals or carbenium ions may be part of the system. The compound may be cyclic, acyclic, linear or mixed, conjugation is the overlap of one p-orbital with another across an intervening σ bond. A conjugated system has a region of overlapping p-orbitals, bridging the interjacent single bonds and they allow a delocalization of pi electrons across all the adjacent aligned p-orbitals. The pi electrons do not belong to a bond or atom. The largest conjugated systems are found in graphene, graphite, conductive polymers, conjugation is possible by means of alternating single and double bonds. As long as each contiguous atom in a chain has an available p-orbital, for example, furan is a five-membered ring with two alternating double bonds and an oxygen in position 1. Oxygen has two pairs, one of which occupies a p-orbital on that position, thereby maintaining the conjugation of that five-membered ring. The presence of a nitrogen in the ring or groups α to the ring like a group, an imine group. There are also types of conjugation. Homoconjugation is an overlap of two separated by a non-conjugating group, such as CH2. For example, the molecule CH2=CH–CH2–CH=CH2 is homoconjugated because the two C=C double bonds are separated by one CH2 group, cyclic compounds can be partly or completely conjugated. Annulenes, completely conjugated monocyclic hydrocarbons, may be aromatic, non-aromatic or anti-aromatic, conjugated, planar, cyclic compounds that follow Hückels rule are aromatic and exhibit an unusual stability. The classic example benzene has a system of 6 π-electrons, which forms the ring along the planar σ-ring with its 12 electrons. Not all compounds with alternating double and single bonds are aromatic, cyclooctatetraene, for example, possesses alternating single and double bonds. The molecule typically adopts a tub conformation, because the p-orbitals of the molecule do not align themselves well in this non-planar molecule, the electrons are not as easily shared between the carbon atoms. The molecule can be considered conjugated, but is neither aromatic. Many pigments make use of conjugated electron systems to absorb visible light, for example, the long conjugated hydrocarbon chain in beta-carotene leads to its strong orange color. When an electron in the system absorbs a photon of light of the right wavelength, in this model the lowest possible absorption energy corresponds to the energy difference between the highest occupied molecular orbital and the lowest unoccupied molecular orbital
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Alcohol
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In chemistry, an alcohol is any organic compound in which the hydroxyl functional group is bound to a saturated carbon atom. The term alcohol originally referred to the alcohol ethanol, the predominant alcohol in alcoholic beverages. The suffix -ol in non-systematic names also typically indicates that the substance includes a functional group and, so. But many substances, particularly sugars contain hydroxyl functional groups without using the suffix, an important class of alcohols, of which methanol and ethanol are the simplest members is the saturated straight chain alcohols, the general formula for which is CnH2n+1OH. The word alcohol is from the Arabic kohl, a used as an eyeliner. Al- is the Arabic definite article, equivalent to the in English, alcohol was originally used for the very fine powder produced by the sublimation of the natural mineral stibnite to form antimony trisulfide Sb 2S3, hence the essence or spirit of this substance. It was used as an antiseptic, eyeliner, and cosmetic, the meaning of alcohol was extended to distilled substances in general, and then narrowed to ethanol, when spirits as a synonym for hard liquor. Bartholomew Traheron, in his 1543 translation of John of Vigo, Vigo wrote, the barbarous auctours use alcohol, or alcofoll, for moost fine poudre. The 1657 Lexicon Chymicum, by William Johnson glosses the word as antimonium sive stibium, by extension, the word came to refer to any fluid obtained by distillation, including alcohol of wine, the distilled essence of wine. Libavius in Alchymia refers to vini alcohol vel vinum alcalisatum, Johnson glosses alcohol vini as quando omnis superfluitas vini a vino separatur, ita ut accensum ardeat donec totum consumatur, nihilque fæcum aut phlegmatis in fundo remaneat. The words meaning became restricted to spirit of wine in the 18th century and was extended to the class of substances so-called as alcohols in modern chemistry after 1850, the term ethanol was invented 1892, based on combining the word ethane with ol the last part of alcohol. In the IUPAC system, in naming simple alcohols, the name of the alkane chain loses the terminal e and adds ol, e. g. as in methanol and ethanol. When necessary, the position of the group is indicated by a number between the alkane name and the ol, propan-1-ol for CH 3CH 2CH 2OH, propan-2-ol for CH 3CHCH3. If a higher priority group is present, then the prefix hydroxy is used, in other less formal contexts, an alcohol is often called with the name of the corresponding alkyl group followed by the word alcohol, e. g. methyl alcohol, ethyl alcohol. Propyl alcohol may be n-propyl alcohol or isopropyl alcohol, depending on whether the group is bonded to the end or middle carbon on the straight propane chain. As described under systematic naming, if another group on the molecule takes priority, Alcohols are then classified into primary, secondary, and tertiary, based upon the number of carbon atoms connected to the carbon atom that bears the hydroxyl functional group. The primary alcohols have general formulas RCH2OH, the simplest primary alcohol is methanol, for which R=H, and the next is ethanol, for which R=CH3, the methyl group. Secondary alcohols are those of the form RRCHOH, the simplest of which is 2-propanol, for the tertiary alcohols the general form is RRRCOH
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Cis-3-Hexen-1-ol
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Cis-3-Hexen-1-ol, also known as -3-hexen-1-ol and leaf alcohol, is a colorless oily liquid with an intense grassy-green odor of freshly cut green grass and leaves. It is produced in small amounts by most plants and it acts as an attractant to many predatory insects, cis-3-Hexen-1-ol is a very important aroma compound that is used in fruit and vegetable flavors and in perfumes. The yearly production is about 30 tonnes, cis-3-Hexen-1-ol is an alcohol and its esters are also important flavor and fragrance raw materials. The related aldehyde cis-3-hexenal has a similar and even stronger smell but is relatively unstable and this compound has been recognized as a pheromone involved in mechanisms and behaviors of attraction in diverse animals such as insects and mammals. However, there is no evidence of its aphrodisiac effects in humans. The popular Mexican alcoholic beverage, mezcal, is found to have enhanced concentrations of this compound when a worm is served in the glass. Pheromone database Molecule of the Month, Hexenal That Worm at the Bottom of Your Mezcal Isn’t a Total Liel
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Perfume
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Perfume is a mixture of fragrant essential oils or aroma compounds, fixatives and solvents - used to give the human body, animals, food, objects, and living-spaces a pleasant scent. Ancient texts and archaeological excavations show the use of perfumes in some of the earliest human civilizations, the word perfume derives from the Latin perfumare, meaning to smoke through. Perfumery, as the art of making perfumes, began in ancient Mesopotamia and Egypt, the worlds first-recorded chemist is considered a woman named Tapputi, a perfume maker mentioned in a cuneiform tablet from the 2nd millennium BC in Mesopotamia. She distilled flowers, oil, and calamus with other aromatics, then filtered, in India, perfume and perfumery existed in the Indus civilization. One of the earliest distillations of Ittar was mentioned in the Hindu Ayurvedic text Charaka Samhita and Sushruta Samhita, in 2004 –2005, archaeologists uncovered what are believed to be the worlds oldest surviving perfumes in Pyrgos, Cyprus. The perfumes date back more than 4,000 years and they were discovered in an ancient perfumery, a 4, 000-square-meter factory housing at least 60 stills, mixing bowls, funnels, and perfume bottles. In ancient times people used herbs and spices, such as almond, coriander, myrtle, conifer resin, the book also described 107 methods and recipes for perfume-making and perfume-making equipment, such as the alembic. The Persian chemist Ibn Sina introduced the process of extracting oils from flowers by means of distillation and he first experimented with the rose. Until his discovery, liquid perfumes consisted of mixtures of oil and crushed herbs or petals, rose water was more delicate, and immediately became popular. Both the raw ingredients and the technology significantly influenced western perfumery and scientific developments. The art of perfumery was known in western Europe from 1221, taking account the monks recipes of Santa Maria delle Vigne or Santa Maria Novella of Florence. In the east, the Hungarians produced in 1370 a perfume made of scented oils blended in an alcohol solution – best known as Hungary Water – at the behest of Queen Elizabeth of Hungary. The art of perfumery prospered in Renaissance Italy, and in the 16th century the personal perfumer to Catherine de Medici, Rene the Florentine and his laboratory was connected with her apartments by a secret passageway, so that no formulae could be stolen en route. Thanks to Rene, France quickly became one of the European centers of perfume, cultivation of flowers for their perfume essence, which had begun in the 14th century, grew into a major industry in the south of France. Between the 16th and 17th centuries, perfumes were used primarily by the wealthy to mask body odors resulting from infrequent bathing, partly due to this patronage, the perfume industry developed. In 1693, Italian barber Giovanni Paolo Feminis created a perfume water called Aqua Admirabilis, today best known as eau de cologne, by the 18th century the Grasse region of France, Sicily, and Calabria were growing aromatic plants to provide the growing perfume industry with raw materials. Even today, Italy and France remain the center of European perfume design, Perfume types reflect the concentration of aromatic compounds in a solvent, which in fine fragrance is typically ethanol or a mix of water and ethanol. Various sources differ considerably in the definitions of perfume types, the intensity and longevity of a perfume is based on the concentration, intensity and longevity of the aromatic compounds, or perfume oils, used
