Darius Molho

La citréomontanine, nouvelle α-pyrone polyéthylénique isolée de Penicillium pedemontanum

Abstract Citreomontanin, a new polyene 2-pyrone was isolated from the mycelium of P. pedemontanum . Based upon spectral data, it was assigned the structure: (all- E )-4-methoxy-5-methyl-6-(7,9,11- trimethyl-1,3,5,7,9,11-tridecahexaenyl)-2 H -pyran-2-one.

Fungal macrolides: Structure determination and biosynthesis of achaetolide, a lactone from Achaetomium cristalliferum

Abstract The structure of a new ten-membered lactone, achaetolide, isolated from cultures of Achaetomium cristalliferum is deduced from its mass and NMR spectra and from the study ofsomederivatives. The 13 C NMR spectra of achaetolide enriched with [1- 13 C], [2- 13 C] and [1, 2- 13 C] acetate established its formation from eight intact acetate units via a precursor octaketide chain.

Isolation of daucane esters from Ferula communis var. Brevifolia

Abstract Three new daucane sesquiterpenes related to jaeschkeanadiol have been isolated from the leaves and the seeds of Ferula communis var. brevifolia. The structures were elucidated by spectroscopic studies and correlated with known compounds.

Ferulenol and ω-hydroxyferulenol, toxic coumarins from Ferula communis var. genuina

Abstract From the root sap of Ferula communis , two isoprenylated 4-hydroxycoumarins, the known ferulenol and the new ω-hydroxyferulenol, were isolated, which both show haemorrhagic action. Their structures were established from MS, IR, 1 H and 13 C NMR spectral analysis.

Xanthones and C-glucosylflavones from Gentiana corymbifera

Abstract A new xanthone and twelve known compounds were isolated from the aerial parts of Gentiana corymbifera . The new xanthone was shown to be 3-methylcorymbiferin (1,8-dihydroxy-3,4,5-trimethoxy-9 H -xanthen-9-one) by spectral and chemical procedures. The chemotaxonomic implications are discussed.

A Chemically Distinctive New Ramalina from Fiji

The new species Ramalina luciae is unique among the sekikaic acid- producing members of the R. farinacea complex in its very low content of homo- sekikaic acid and in its lack of mono-O-demethyl derivatives of homosekikaic acid.

Biosynthesis of citreomontanin in Penicillium pedemontanum

Abstract The 13 C NMR spectrum of citreomontanin has been fully assigned by analysis in the presence of a shift reagent. The intramolecular distribution patt

Structure des acides isomuronique et neuropogolique, nouveaux acides aliphatiques du lichen Neuropogon trachycarpus

Abstract The structures of two new aliphatic acids, isomuronic and neuropogolic acid, from the lichen Neuropogon trachycarpus , were established by spectroscopic (MS, 1 H and 13 C NMR) and chemical evidence. Circular dichroism data allowed the configuration of isomuronic acid to be assigned as 2 R .

Rearrangement du cation isoflavylium en aryl-2 benzofuranne

Abstract Easy conversion of isoflavylium salts into 2-arylbenzofurans under mild perhydrol oxidation conditions suggests an alternative biogenetic pathway.

Cis-dimethoxylation de perchlorates d'alkoxy-3 flavylium.

Resume Thallium (III) trinitrate oxidation of 3-methoxy flavylium salts or bridged analogue gave polymethoxyflavans which form flavones on acidic hydrolysis.