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Anziaic Acid
Anziaic acid is a depside found in lichens. It gives a red reaction in the C test. The two phenolic rings have a pentyl side chain. It is an ester dimer of olivetolic acid. Anziaic acid works as an antibacterial compound by inhibiting topoisomerase. Production Anziaic acid has been artificially produced from olivetolic acid by benzylation of the ''O''-phenol positions, and then condensing with trifluoroacetic anhydride. Properties Anziaic acid is colourless. It can be dissolved in ethanol, ethanol-water mixture, or cyclohexane-benzene mixture. Related Perlatolic acid, dihydropicrolichenic acid, 2'-''O''-methylanziaic acid, 2-''O''-methylperlatolic acid, 2'-''O''-methylperlatolic and planaic acid are derivatives of anziaic acid, where a methyl group replaces a hydrogen in some of the hydroxy positions on the rings. Occurrence Anziaic acid is found in Parmeliaceae including ''Hypotrachyna'', ''Stereocaulon ''Stereocaulon'' is a genus of lichens. Members of ''Stereocaulon'' a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depside
A depside is a type of polyphenolic compound composed of two or more monocyclic aromatic units linked by an ester bond. Depsides are most often found in lichens, but have also been isolated from higher plants, including species of the Ericaceae, Lamiaceae, Papaveraceae and Myrtaceae. Certain depsides have antibiotic, anti- HIV, antioxidant, and anti-proliferative activity ''in vitro''. As inhibitors of prostaglandin synthesis and leukotriene B4 biosynthesis, some depsides have ''in vitro'' anti-inflammatory activity. A depsidase is a type of enzyme that cuts depside bonds. One such enzyme is tannase. Examples Gyrophoric acid, found in the lichen '' Cryptothecia rubrocincta'', is a depside. Merochlorophaeic acid, isolated from lichens of the genus '' Cladonia'', is an inhibitor of prostaglandin synthesis. Some depsides are described as anti-HIV. See also *Salsalate homodimer formed from self-condensation of salicylic acid Salicylic acid is an organic compound with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C Test
A spot test in lichenology is a spot analysis used to help identify lichens. It is performed by placing a drop of a chemical on different parts of the lichen and noting the colour change (or lack thereof) associated with application of the chemical. The tests are routinely encountered in dichotomous keys for lichen species, and they take advantage of the wide array of lichen products produced by lichens and their uniqueness among taxa. As such, spot tests reveal the presence or absence of chemicals in various parts of a lichen. They were first proposed by the botanist William Nylander (botanist), William Nylander in 1866. Three common spot tests use either 10% aqueous potassium hydroxide, KOH solution (K test), saturated aqueous solution of bleaching powder or calcium hypochlorite (C test), or 5% alcoholic p-phenylenediamine, ''p''-phenylenediamine solution (P test). The colour changes occur due to presence of particular secondary metabolites in the lichen. There are several other l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentyl
Pentyl is a five-carbon alkyl group or substituent with chemical formula -C5H11. It is the substituent form of the alkane pentane. In older literature, the common non-systematic name amyl was often used for the pentyl group. Conversely, the name pentyl was used for several five-carbon branched alkyl groups, distinguished by various prefixes. The nomenclature has now reversed, with "amyl" being more often used to refer to the terminally branched group also called isopentyl, as in amobarbital. A cyclopentyl group is a ring with the formula -C5H9. The name is also used for the pentyl radical, a pentyl group as an isolated molecule. This free radical is only observed in extreme conditions. Its formula is often written "•" or "• " to indicate that it has one unsatisfied valence bond. Older "pentyl" groups The following names are still used sometimes: Pentyl radical The free radical pentyl was studied by J. Pacansky and A. Gutierrez in 1983. The radical was obtained by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olivetolic Acid
Olivetolic acid is an organic compound that is an intermediate in the biosynthetic pathway of the cannabinoids in ''Cannabis sativa ''Cannabis sativa'' is an annual herbaceous flowering plant indigenous to Eastern Asia, but now of cosmopolitan distribution due to widespread cultivation. It has been cultivated throughout recorded history, used as a source of industrial fibe ...''. The ester dimer of olivetolic acid, anziaic acid, is found in lichen. References {{organic-compound-stub Benzoic acids Cannabinoids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topoisomerase
DNA topoisomerases (or topoisomerases) are enzymes that catalyze changes in the topological state of DNA, interconverting relaxed and supercoiled forms, linked (catenated) and unlinked species, and knotted and unknotted DNA. Topological issues in DNA arise due to the intertwined nature of its double-helical structure, which, for example, can lead to overwinding of the DNA duplex during DNA replication and transcription. If left unchanged, this torsion would eventually stop the DNA or RNA polymerases involved in these processes from continuing along the DNA helix. A second topological challenge results from the linking or tangling of DNA during replication. Left unresolved, links between replicated DNA will impede cell division. The DNA topoisomerases prevent and correct these types of topological problems. They do this by binding to DNA and cutting the sugar-phosphate backbone of either one (type I topoisomerases) or both (type II topoisomerases) of the DNA strands. This transien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trifluoroacetic Anhydride
Trifluoroacetic anhydride (TFAA) is the acid anhydride of trifluoroacetic acid. It is the perfluorinated derivative of acetic anhydride. Preparation Trifluoroacetic anhydride was originally prepared by the dehydration of trifluoroacetic acid with phosphorus pentoxide. The dehydration might also be carried out with excess α-halogenated acid chlorides. For example, with dichloroacetyl chloride: : 2 CF3COOH + Cl2CHCOCl → (CF3CO)2O + Cl2CHCOOH + HCl Uses Trifluoroacetic anhydride has various uses in organic synthesis. It may be used to introduce the corresponding trifluoroacetyl group, for which it is more convenient than the corresponding acyl chloride, trifluoroacetyl chloride, which is a gas. It can be used to promote reactions of carboxylic acids, including nucleophilic acyl substitution, Friedel-Crafts acylation, and acylation of other unsaturated compounds. Other electrophilic aromatic substitution reactions can also be promoted with trifluoroacetic anhydride, includi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methyl Group
In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula . In formulas, the group is often abbreviated as Me. This hydrocarbon group occurs in many organic compounds. It is a very stable group in most molecules. While the methyl group is usually part of a larger molecule, bounded to the rest of the molecule by a single covalent bond (), it can be found on its own in any of three forms: methanide anion (), methylium cation () or methyl radical (). The anion has eight valence electrons, the radical seven and the cation six. All three forms are highly reactive and rarely observed. Methyl cation, anion, and radical Methyl cation The methylium cation () exists in the gas phase, but is otherwise not encountered. Some compounds are considered to be sources of the cation, and this simplification is used pervasively in organic chemistry. For example, protonation of methanol gives an elect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parmeliaceae
The Parmeliaceae is a large and diverse family of Lecanoromycetes. With over 2700 species in 71 genera, it is the largest family of lichen-forming fungi. The most speciose genera in the family are the well-known groups: '' Xanthoparmelia'' ( 822 species), ''Usnea'' (355 species), ''Parmotrema'' ( 255 species), and ''Hypotrachyna'' (262 species). Nearly all members of the family have a symbiotic association with a green alga (most often ''Trebouxia'' spp., but '' Asterochloris'' spp. are known to associate with some species).Miadlikowska, J. ''et al.'' (2006). New insights into classification and evolution of the Lecanoromycetes (Pezizomycotina, Ascomycota) from phylogenetic analyses of three ribosomal RNA- and two protein-coding genes. ''Mycologia'' 98: 1088-1103. http://www.mycologia.org/cgi/reprint/98/6/1088.pdf The majority of Parmeliaceae species have a foliose, fruticose, or subfruticose growth form. The morphological diversity and complexity exhibited by this group is en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypotrachyna
''Hypotrachyna'' is a genus of lichenized fungi within the family Parmeliaceae The Parmeliaceae is a large and diverse family of Lecanoromycetes. With over 2700 species in 71 genera, it is the largest family of lichen-forming fungi. The most speciose genera in the family are the well-known groups: '' Xanthoparmelia'' ( .... According to the ''Dictionary of the Fungi'' (10th edition, 2008), the widespread genus contains about 198 species. ''Hypotrachyna'' was circumscribed by American lichenologist Mason Ellsworth Hale Jr in 1974. Species *'' Hypotrachyna adaffinis'' *'' Hypotrachyna addita'' *'' Hypotrachyna adducta'' *'' Hypotrachyna adjuncta'' *'' Hypotrachyna aguirrei'' *'' Hypotrachyna ahtiana'' *'' Hypotrachyna alectorialiorum'' *'' Hypotrachyna andensis'' *'' Hypotrachyna angustissima'' *'' Hypotrachyna anzeana'' *'' Hypotrachyna aspera'' *'' Hypotrachyna bahiana'' *'' Hypotrachyna bogotensis'' *'' Hypotrachyna booralensis'' *'' Hypotrachyna boquetensis'' *'' Hypo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
