Results 131 to 140 of about 1,299 (187)

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

Variability of the composition of orcinol depsidones in Hypogymnia vittata and H. subduplicata

Novosti sistematiki nizshikh rastenii
The variability of the composition of secondary metabolites in Hypogymnia vittata and H. subduplicata was studied. Three chemotypes have been identified for H.
Zh. O. Zholobova, I. A. Prokopyev, D. A. Frolova   +2 more
semanticscholar   +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

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

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

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

α-Glucosidase Inhibitory Depsidones from the Lichen Parmotrema tsavoense

Planta Medica, 2020
Chemical investigation of the lichen Parmotrema tsavoense led to the isolation of 5 new depsidones, parmosidones F – J (1 – 5). These compounds were structurally elucidated using spectroscopic methods including HRESIMS and 2D NMR data.
T. Duong, Tai-Xuan-Hoa Hang, P. Pogam, Thanh-Nha Tran, D. Mac, Minh-Hiep Dinh, J. Sichaem   +6 more
semanticscholar   +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

Liquid chromatography-electrospray ionization-mass spectrometry/mass spectrometry characterization of depsides and depsidones from the Chilean lichen Parmotrema perlatum

European Journal of Mass Spectrometry
Lichens are recognized by their unique compounds and diverse applications in food, medicines, and cosmetics. Using ultra-high pressure liquid chromatography, coupled with a high-resolution mass spectrometer, metabolomic profiling of the lichen Parmotrema
Grover Castañeta, B. Sepúlveda, C. Areche   +2 more
semanticscholar   +1 more source