Results 141 to 150 of about 911 (189)

A new depsidone from Aspergillus unguis

Phytochemistry, 1972
R F Vesonder, D Weisleder
exaly   +2 more sources

Antioxidant activity of depsides and depsidones

Phytochemistry, 1994
The 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, E, Fernández, W, Quilhot, E, Lissi   +3 more
openaire   +2 more sources

Structure of the lichen depsidone pannarin

Journal of the Chemical Society, Chemical Communications, 1974
The published structure of pannarin{2-chloro-6-hydroxy-3-methoxy-1,4,8-trimethyl-11-oxo-11H-dibenzo[b,e]-[1,4]dioxepin-7-carbaldehyde}(1) is revised to 2-chloro-3-hydroxy-8-methoxy-1,6,9-trimethyl-11-oxo-11H-dibenzo[b,e][1,4]dioxepin-4-carbaldehyde (21), in the light of a combination of degradative, spectroscopic, and synthetic studies.
David A. Jackman, Melvyn V. Sargent, John A. Elix   +2 more
openaire   +1 more source

Structure of the lichen depsidone gangaleoidin

Journal of the Chemical Society, Perkin Transactions 1, 1975
As a result of degradative, spectroscopic, and synthetic evidence the structure of the lichen depsidone gangaleoidin is revised to methyl 2,4-dichloro-3-hydroxy-8-methoxy-1,6-dimethyl-11-oxo-11H-dibenzo [b,e][1,4]dioxepin-7-carboxylate. Gangaleoidin was degraded to methyl 3-(2-methoxycarbonyl-5-methoxy-3-methylphenoxy)-4,6-dimethoxy-2-methylbenzoate ...
Melvyn V. Sargent, Paul Vogel, John A. Elix   +2 more
openaire   +1 more source

Depsidone synthesis. IV. Caloploicin

Australian Journal of Chemistry, 1976
The synthesis of the lichen depsidone caloploicin (2,4,7-trichloro-3-hydroxy-8-methoxy-1,6,9- trimethyldibenzo[b,e][l,4]dioxepin-11-one) (1) by oxidative coupling of 5'-chloro-2,2',4-trihydroxy-4- methoxy-3',6,6'-trimethylbenzophenone (23), and subsequent steps, is described.
MV Sargent, P Vogel
openaire   +1 more source

Depsidones from the Endophytic Fungus BCC 8616

Journal of Natural Products, 2006
Three new depsidones (1-3) have been isolated from the endophytic fungus BCC 8616 and their structures analyzed on the basis of spectroscopic data interpretation. Compound 1 exhibited weak cytotoxic activity against breast and epidermoid carcinoma cell lines.
Pattama, Pittayakhajonwut, Aibrohim, Dramae, Siribhorn, Madla, Nattapat, Lartpornmatulee, Nattawut, Boonyuen, Morakot, Tanticharoen   +5 more
openaire   +2 more sources

Three New Lichen Depsidones

Australian Journal of Chemistry, 1987
The depsidones a- acetylconstictic acid (5-acetoxymethyl-1,4-dihydroxy-10-methoxy-8-methyl-3,7-dioxo-1,3-dihydro-7 H- isobenzofuro [4,5- b][l,4] benzodioxepin-ll-carbaldehyde ) (6), substictic acid (1,4-dihydroxy-10-methoxy-8-methy1-3,7-dioxo- 1,3-dihydro-7 H- isobenzofuro [4,5-b][1,4]benzodioxepin-11-carbaldehyde) (7) and conphysodalic acid (9 ...
JA Elix, KL Gaul, PW James, OW Purvis
openaire   +1 more source

ChemInform Abstract: DEPSIDONE SYNTHESIS. PART 16. BENZOPHENONE‐GRISA‐3′,5′‐DIENE‐2′,3‐DIONE‐DEPSIDONE INTERCONVERSION: A NEW THEORY OF DEPSIDONE BIOSYNTHESIS

Chemischer Informationsdienst, 1981
AbstractOxidative Kupplung der substituierten 2,2′‐Dihydroxy‐4‐methoxy‐benzophenone (I), (IV) bzw. (VII) mit K3 [Fe(CN)6] unter optimalen Bedingungen liefert die Grisadiendione (II), (V) bzw. (VIII), die sich bei Thermolyse in fester Form oder in Lösungsmitteln wie TFA/ CHz C12, Diphenylether oder Phenetol in die Depsidone (III), (VI) bzw.
T. SALA, M. V. SARGENT
openaire   +1 more source

Depsidone synthesis. Part 16. Benzophenone–grisa-3′,5′-diene-2′,3-dione–depsidone interconversion: a new theory of depsidone biosynthesis

J. Chem. Soc., Perkin Trans. 1, 1981
The synthesis of a number of grisa-3′,5′-diene-2′,3-diones by oxidative coupling of substituted 2,2′-dihydroxy-4-methoxybenzophenones is described. The rearrangement of these grisadienediones to depsidones under basic, acidic, and thermal conditions is described and the mechanisms of these reactions are discussed.
Tony Sala, Melvyn V. Sargent
openaire   +1 more source

Depsidones from Anomalographis madeirensis

Biochemical Systematics and Ecology, 1999
0 ...
González, Antonio G., Hernández, Consuelo, Rodríguez, Elsa M., Del Carmen Alfayate, M., Bermejo, Jaime   +4 more
openaire   +2 more sources