Castalagin is an ellagitannin, a type of hydrolyzable tannin, found in oak and chestnut wood and in the stem barks of Anogeissus leiocarpus and Terminalia avicennoides. Castalagin is the -isomer of vescalagin, during aging of alcohols in oak barrels, vescalagin can be extracted from the wood and can subsequently be transformed into new derivatives by chemical reactions. Vescalagin is one of the most abundant ellagitannins extracted from oak wood using white wine, the flavono-ellagitannin known as acutissimin A is created when the oak tannin vescalagin interacts with a flavonoid in wine. In some plants including oak and chestnut, the ellagitannins are formed from 1,2,3,4, 6-pentagalloyl-glucose, castalagin thus forms from a pentagalloyl-glucose structure. Castalagin and vescalagin can be polymerized in their corresponding dimers roburin A and roburin D. Grandinin is a castalagin glycoside by binding of the pentose lyxose
Ellagic acid is a natural phenol antioxidant found in numerous fruits and vegetables. The antiproliferative and antioxidant properties of ellagic acid have prompted research into its health benefits. Ellagic acid is the dilactone of hexahydroxydiphenic acid, plants produce ellagic acid from hydrolysis of tannins such as ellagitannin and geraniin. Urolithins are microflora human metabolites of dietary ellagic acid derivatives Ellagic acid was first discovered by chemist Henri Braconnot in 1831, maximilian Nierenstein prepared this substance from algarobilla, oak bark, pomegranate and valonea in 1905. He suggested its formation from galloyl-glycine by Penicillium in 1915, löwe was the first person to synthesize ellagic acid by heating gallic acid with arsenic acid or silver oxide. Ellagic acid is found in species like the North American white oak. The macrophyte Myriophyllum spicatum produces ellagic acid, Ellagic acid can be found in the medicinal mushroom Phellinus linteus. The highest levels of acid are found in walnuts, cranberries, strawberries.
It is found in peach, and other plant foods, Ellagic acid has antiproliferative and antioxidant properties in a number of in vitro and small-animal models. The antiproliferative properties of acid may be due to its ability to directly inhibit the DNA binding of certain carcinogens, including nitrosamines. As with other antioxidants, ellagic acid has a chemoprotective effect in cellular models by reducing oxidative stress. Ellagic acid has been marketed as a supplement with a range of claimed benefits against cancer, heart disease. Ellagic acid has been identified by the U. S. Food, such as urolithin A, are microflora human metabolites of dietary ellagic acid derivatives that are under study as anti-cancer agents. Claims that ellagic acid can treat or prevent cancer in humans have not been proven, list of ineffective cancer treatments A Food-Based Approach to the Prevention of Gastrointestinal Tract Cancers - video lecture dedicated mainly to ellagic acid. Read by Dr. Gary D. Stoner from the Ohio State University Comprehensive Cancer Center, polyphenols as cancer chemopreventive agents, J.
Cell Biochem Suppl
Simplified molecular-input line-entry system
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 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
It can be found in Punica granatum or in the leaves of Terminalia catappa, a plant used to treat dermatitis and hepatitis. It is reported in Combretum glutinosum, all three species being Myrtales, the two last being Combretaceae and it is a highly active carbonic anhydrase inhibitor. The molecule contains a gallagic acid component linked to a glucose
The pomegranate ellagitannins, which include punicalagin isomers, are ellagitannins found in the fruit, bark or heartwood of pomegranates. As the chemistry of punicalagins became known it was found to be not unique to pomegranate, punicalagins are present in numerous species of the genus Terminalia, species chebula Retz. myriocarpa and citrina. They have been isolated from Cistus salvifolius and Combretum molle, pomegranate fruits natural phenols can be extracted with ethyl acetate and fractionation can afford the ellagitannin punicalagins. A few dietary supplements and nutritional ingredients are available that contain extracts of whole pomegranate and/or are standardized to punicalagins, extracts of pomegranate are Generally Recognized As Safe by the United States. Pedunculagin, a found in the pericarp of the pomegranate