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Synthesis of Further Lichen Depsides
Australian Journal of Chemistry, 1993The unambiguous total synthesis of 18 lichen depsides has been achieved by the condensation of an appropriately substituted orsellinic acid and protected phenol in the key step, followed by subsequent deprotection and/or secondary reduction. The natural occurrence of the first meta-depside involving substitution at the 5??-position of the B-ring has ...
JA Elix +6 more
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Antioxidant activity of depsides and depsidones
Phytochemistry, 1994The antioxidant activity of lichenic metabolites, depsides and depsidones, was assessed by their effects as inhibitors of rat brain homogenate auto-oxidation and beta-carotene oxidation. The results obtained in both systems indicate that lichenic metabolites afford a moderate protection in the microM concentration range. The largest effect was measured
M E, Hidalgo +3 more
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Nature, 1966
THIS communication reports our finding of neochlorogenic, isochlorogenic, and 3-O-feruloylquinic acids in the leaves of sunflowers, Helianthus annuus, Russian Mammoth variety. The well-known chlorogenic acid (3-O-caffeoylquinic acid) has been previously found in sunflowers by Urban1 and its presence there has been confirmed by Watanabe et al ...
A. ZANE, S. H. WENDER
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THIS communication reports our finding of neochlorogenic, isochlorogenic, and 3-O-feruloylquinic acids in the leaves of sunflowers, Helianthus annuus, Russian Mammoth variety. The well-known chlorogenic acid (3-O-caffeoylquinic acid) has been previously found in sunflowers by Urban1 and its presence there has been confirmed by Watanabe et al ...
A. ZANE, S. H. WENDER
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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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New Depsides From Erioderma Lichens
Australian Journal of Chemistry, 1987A chemosyndrome of para- depsides based on methyl 4-O-demethylbarbatate (3) has been detected in Erioderma lichens and the structures of the metabolites have been established by unambiguous syntheses. New depsides include methyl 5-chloro-4-O-demethylbarbatate (4), methyl eriodermate (5), methyl 2'-0-methyleriodermate (6), methyl 2-O-methyleriodermate ...
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Tert-butanolysis of lichen depsides
Phytochemistry, 1984Abstract The scope and limit of the tert-butanolysis of 12 lichen depsides is described. Neither 2-O-methylated nor 2-O-acetylated compounds are cleaved by heating with tert-butanol.
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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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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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