Results 161 to 170 of about 1,481 (197)
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Methyl β-Orcinolcarboxylate and Depsides from Parmelia furfuracea
Journal of Natural Products, 1985Parmelia furfuracea, a common conifer lichen, produce antimicrobical constituents whose extracts have been utilized to give base materials for perfumes. Crude extracts of this lichen were tested against representative different class of microorganisms.
Caccamese, S. +3 more
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Depsides from the Petals ofPapaver rhoeas
Planta Medica, 2004Two new depsides as well as the known p-hydroxybenzoic acid and its methyl ester, protocatechuic acid, 2-(4-hydroxyphenyl)-ethanol, 2-(3,4-dihydroxyphenyl)-ethanol and the flavonoids kaempferol, quercetin, luteolin and hypolaetin and the glycosides 3- O-beta- D-glucopyranosylquercetin (isoquercitrine), 3- O-beta- D-glucopyranosylkaempferol (astragaline)
Marita, Hillenbrand +2 more
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Cleavage of depsides by tert-butyl alcohol
Phytochemistry, 1979Abstract Depsides have been found to cleave readily on prolonged heating with t -butyl alcohol to give t -butyl esters and the free phenols.
Frank W. Bachelor +2 more
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Solid phase synthesis of depsides and depsipeptides
Tetrahedron Letters, 1999Abstract A general solid phase methodology for the synthesis of depside and depsipeptide chains from optically active α-hydroxy acids and α-amino acids is reported. The automated preparation of depsides (97% yield per cycle) made up from the same enantiomer [i.e. H-[( S )-Man] 8 -OH, 1 ] † by both enantiomers [i.e. H-[( R )-Man-( S )-Man] 4 -OH,
Oliver Kuisle +2 more
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Synthesis of the Aliphatic Depside (+)-Bourgeanic Acid
The Journal of Organic Chemistry, 1994The lichen metabolite (+)-bourgeanic acid (1) was synthesized in 12 steps and 3.4% overall yield from (R)-2-methyl-1-iodobutane (53) by a sequence which confirmed that this aliphatic depside is the self-este- rification product of (2R,3S,4R,6R)-2,4,6-trimethyl-3-hydroxyoctanoic acid.
James D. White, Alan T. Johnson
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Chlorogenic acids and related depsides
The Botanical Review, 1964Isolation and Chemistry 668 General Isolation Procedures 668 The Chlorogenic Acids 671 Additional Quinic Acid Depsides 677 Other Phenylpropenoyl Depsides 680 Transesterification Reactions in Quinic Acid Depsides 681 The Chlorogenic Acid-Caffeine Complex ...
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Radiolysis of Quercetin in Methanol Solution: Observation of Depside Formation
Journal of Agricultural and Food Chemistry, 2002Radiolysis of the flavonol quercetin, a natural antioxidant, was performed in methanol. The degradation process was followed by HPLC analyses. The major product was identified as a depside (Q1) by NMR and LC-MS. The G(Q1) radiolytic factor was plotted versus the initial concentration of quercetin.
Abdelghafour, Marfak +5 more
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A theory of biogenesis of lichen depsides and depsidones
Proceedings of the Indian Academy of Sciences - Section A, 1944Lichen depsides and depsidones are considered to arise from a common source (XIV) which originates from aldol condensation between a hexose and a biose and elimination of water. Oxidation and reduction lead to various modifications of this C8 unit and increase in the length of the sidechain arises from condensation with simple sugars and reduction ...
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New Depsides in Stirtonia ramosa (Ascomycotina, Arthoniaceae)
The Bryologist, 1990Stirtonia ramosa, a corticolous crustose lichen from the Andaman Islands, contains two new para-depsides, 4-O-demethylsuperconfluentic and 2'-O-methylnorsuperphyllinic acids. Chemical structures are proposed from microchemical identification of the hydrolysis products of the depsides and their methyl esters.
Chicita F. Culberson +3 more
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Synthesis of depsides and their biological activity
Synthesized depsides were modified based on the core structure of jaboticabin, to enhance its biological activities. Desired depsides were synthesized through an esterification with methyl 2-(2- hydroxyphenyl) acetate (NT0) and a carboxylic acid compound. DCC and DMAP were required to activate the carboxylic group and solvent used was DCM. 2-(2-Methoxy-openaire +1 more source