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
Sodium channels are integral membrane proteins that form ion channels, conducting sodium ions through a cells plasma membrane. They are classified according to the trigger that opens the channel for such ions, in excitable cells such as neurons and certain types of glia, sodium channels are responsible for the rising phase of action potentials. These channels go through 3 different states called as resting and inactive states, even though the resting and inactive states wouldnt allow the ions to flow through the channels the difference exists with respect to their structural conformation. Sodium channels are selective for the transport of sodium ions across cell membranes. The high selectivity with respect to the ion is achieved in many different ways. All involve encapsulation of the ion in a cavity of specific size within a larger molecule. Sodium channels consist of large α subunits that associate with proteins, an α subunit forms the core of the channel and is functional on its own. When the α subunit protein is expressed by a cell, it is able to form channels that conduct Na+ in a voltage-gated way, when accessory proteins assemble with α subunits, the resulting complex can display altered voltage dependence and cellular localization.
The α-subunit has four domains, labeled I through IV, each containing six membrane-spanning segments. The highly conserved S4 segment acts as the voltage sensor. The voltage sensitivity of this channel is due to amino acids located at every third position. When stimulated by a change in voltage, this segment moves toward the extracellular side of the cell membrane. The ions are conducted through a pore, which can be broken into two regions, the more external portion of the pore is formed by the P-loops of the four domains. This region is the most narrow part of the pore and is responsible for its ion selectivity, the inner portion of the pore is formed by the combined S5 and S6 segments of the four domains. The region linking domains III and IV is important for channel function and this region plugs the channel after prolonged activation, inactivating it. Voltage-gated Na+ channels have three main states, closed and inactivated. Forward/back transitions between states are correspondingly referred to as activation/deactivation, inactivation/reactivation, and recovery from inactivation/closed-state inactivation.
Closed and inactivated states are ion impermeable, because the voltage across the membrane is initially negative, as its voltage increases to and past zero, it is said to depolarize
L-DOPA is an amino acid that is made and used as part of the normal biology of humans, some animals and plants. Some animals and humans make it via biosynthesis from the amino acid L-tyrosine, L-DOPA is the precursor to the neurotransmitters dopamine and epinephrine collectively known as catecholamines. Furthermore, L-DOPA itself mediates neurotrophic factor release by the brain, L-DOPA can be manufactured and in its pure form is sold as a psychoactive drug with the INN levodopa, trade names include Sinemet, Atamet, Stalevo and Prolopa. As a drug, it is used in the treatment of Parkinsons disease. L-DOPA has a counterpart with opposite chirality, D-DOPA, as is true for many molecules, the human body produces only one of these isomers. The enantiomeric purity of L-DOPA may be analyzed by determination of the rotation or by chiral thin-layer chromatography. L-DOPA crosses the protective barrier, whereas dopamine itself cannot. Thus, L-DOPA is used to increase dopamine concentrations in the treatment of Parkinsons disease and this treatment was made practical and proven clinically by George Cotzias and his coworkers, for which they won the 1969 Lasker Prize.
Once L-DOPA has entered the central system, it is converted into dopamine by the enzyme aromatic L-amino acid decarboxylase. Pyridoxal phosphate is a cofactor in this reaction, and may occasionally be administered along with L-DOPA. Besides the central system, L-DOPA is converted into dopamine from within the peripheral nervous system. Excessive peripheral dopamine signaling causes many of the side effects seen with sole L-DOPA administration. In addition, L-DOPA, co-administered with a peripheral DDCI, has been investigated as a treatment for restless leg syndrome. However, studies have demonstrated no clear picture of reduced symptoms, the two types of response seen with administration of L-DOPA are, The short-duration response is related to the half-life of the drug. The longer-duration response depends on the accumulation of effects over at least two weeks, during which ΔFosB accumulates in nigrostriatal neurons. In the treatment of Parkinsons disease, this response is evident only in early therapy, L-DOPA is produced from the amino acid L-tyrosine by the enzyme tyrosine hydroxylase.
It is the precursor for the monoamine or catecholamine neurotransmitters dopamine, Dopamine is formed by the decarboxylation of L-DOPA by aromatic L-amino acid decarboxylase. L-DOPA can be metabolized by catechol-O-methyl transferase to 3-O-methyldopa
Phenylalanine is an α-amino acid with the formula C 9H 11NO2. It can be viewed as a benzyl group substituted for the group of alanine. This essential amino acid is classified as neutral, and nonpolar because of the inert, the L-isomer is used to biochemically form proteins, coded for by DNA. The codons for L-phenylalanine are UUU and UUC, Phenylalanine is a precursor for tyrosine, the monoamine neurotransmitters dopamine and epinephrine, and the skin pigment melanin. Phenylalanine is found naturally in the breast milk of mammals and it is used in the manufacture of food and drink products and sold as a nutritional supplement for its reputed analgesic and antidepressant effects. It is a precursor to the neuromodulator phenethylamine, a commonly used dietary supplement. The first description of phenylalanine was made in 1879, when Schulze and Barbieri identified a compound with the formula, C9H11NO2. In 1882, Erlenmeyer and Lipp first synthesized phenylalanine from phenylacetaldehyde, hydrogen cyanide, the genetic codon for phenylalanine was first discovered by J.
Heinrich Matthaei and Marshall W. Nirenberg in 1961. This discovery helped to establish the nature of the relationship that links information stored in genomic nucleic acid with protein expression in the living cell. As an essential amino acid, phenylalanine is not synthesized de novo in humans and other animals, good sources of phenylalanine are eggs, liver, beef and soybeans. L-Phenylalanine is biologically converted into L-tyrosine, another one of the DNA-encoded amino acids, L-tyrosine in turn is converted into L-DOPA, which is further converted into dopamine and epinephrine. The latter three are known as the catecholamines, Phenylalanine uses the same active transport channel as tryptophan to cross the blood–brain barrier. The corresponding enzymes in for those compounds are the amino acid hydroxylase family. Phenylalanine is the compound used in the synthesis of flavonoids. Lignan is derived from phenylalanine and from tyrosine, Phenylalanine is converted to cinnamic acid by the enzyme phenylalanine ammonia-lyase.
The genetic disorder phenylketonuria is the inability to metabolize phenylalanine because of a lack of the enzyme phenylalanine hydroxylase, individuals with this disorder are known as phenylketonurics and must regulate their intake of phenylalanine. A variant form of phenylketonuria called hyperphenylalaninemia is caused by the inability to synthesize a cofactor called tetrahydrobiopterin, pregnant women with hyperphenylalaninemia may show similar symptoms of the disorder but these indicators will usually disappear at the end of gestation. Pregnant women with PKU must control their blood phenylalanine levels even if the fetus is heterozygus for the defective gene because the fetus could be affected due to hepatic immaturity
Dihydrexidine is a moderately selective full agonist at the dopamine D1 and D5 receptors. It has approximately 10-fold selectivity for D1 and D5 over the D2 receptor, although dihydrexidine has some affinity for the D2 receptor, it has functionally selective D1 signaling, thereby explaining why it lacks D2 agonist behavioral qualities. Dihydrexidine has shown impressive antiparkinson effects in the MPTP-primate model, and has investigated for the treatment of Parkinsons disease. In an early clinical trial the drug was given intravenously and led to profound hypotension so development was halted, the drug was resurrected when it was shown that smaller subcutaneous doses were safe. This led to a study in schizophrenia and current clinical trials to assess its efficacy in improving the cognitive and working memory deficits in schizophrenia. There have been several reviews of relevance to the compound
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, Google Chrome and Scriptable Molecular Graphics in Web Browsers without Java3D