Emile M. Gaydou

Spectrometric identifications of sesquiterpene alcohols from niaouli (Melaleuca quinquenervia) essential oil

Oxidation and reduction reactions on alloaromadendrene and aromadendrene sesquiterpene hydrocarbons have been investigated in order to produce alcohols with an aromadendrene skeleton for checking the chemical structure and therefore the identity of one main alcohol present in niaouli (Melaleuca quinquenervia) essential oil. Oxidation using m-chloroperbenzoic acid was carried out to produce two diastereoisomer epoxides and two corresponding aldehyde isomers for each sesquiterpene. Epoxide reductions yielded two alcohols ledol and viridiflorol, from alloaromadendrene and globulol and epiglobulol from aromadendrene. The structure determination of all compounds, i.e. epoxides, aldehydes, and alcohols, was achieved using spectrometric methods: 2D-NMR and mass spectroscopy. The stereochemistry of known sesquiterpenic alcohols, viridiflorol and ledol, has been unambiguously established.

New exudate flavonoids of species from the Chrysanthemum complex (Asteraceae-Anthemideae)

Chrysanthemum segetum L., C. coronarium L. and Heteranthemis viscidehirta Schott are annual representatives of the subtribe Chrysantheminae Less. emend. Bremer (Anthemideae-Asteraceae). Contrary to earlier concepts, Chrysanthemum comprises only two species, occurring in the Mediterranean. The monotypic genus Heteranthemis, earlier considered to be Chrysanthemum, is distributed in the same area. This subtribe comprises further the Macaronesian endemic Argyranthemum Web. ex Schultz-Bip. (24 species) and the annual monotypic Ismelia Cass. (= C. carinatum; Bremer and Humphries, 1993). Phylogenetic studies confirmed the monophyly of this group (Francisco-Ortega et al., 1997; Oberprieler and Vogt, 2000). Chrysanthemum segetum L., C. coronarium L. and Heteranthemis viscidehirta were cultivated in the Botanischer Garten der Technischen Universitat Darmstadt. Voucher specimens are deposited in the herbarium of the Institut fur Botanik in

Phospholipid FA from Indian Ocean Tunicates Eudistoma bituminis and Cystodytes violatinctus

Two tunicates (Fudistoma bituminis and Cystodytes violatinctus, family Polycitoridae) were investigated for the FA content of their phospholipids. GC-MS analysis of their methyl esters and N-acyl pyrrolidides revealed 40 FA in E. bituminis, and 26 in C. violatinctus. In both cases, the most abundant FA were the saturated ones (C10 to C18). Cystodytes violatinctus contained considerable oleic acid (20%). Both E. bituminis and C. violatinctus contained phytanic acid and Δ10-unsaturated FA, which had not previously been found in such organisms. The two tropical tunicates contained only trace amounts of PUFA, which are usually predominant in this phylum.

Two-dimensional nuclear magnetic resonance of sesquiterpenes. Part 2. Total assignment of (+)-aromadendrene, (+)-longicyclene, and γ-gurjunene by the two-dimensional INADEQUATE method

Autocorrelated 13C–13C double quantum coherence two-dimensional n.m.r. spectroscopy has been used for an unambiguous complete assignment of the 13C resonances of three sesquiterpenes, (+)-aromadendrene, (+)-longicyclene, and γ-gurjunene

2'-Hydroxy-3'-methoxy-5'-flavonesulfonic Acid Trihydrate: a New Zwitterion

The title compound, C16H12O7S.3H2O, displays an anionic part, the deprotonated sulfonic group and a cationic part, the protonated carbonyl group, indicative of a zwitterionic structure. These two parts in different molecules are linked by hydrogen bonding involving three water molecules.