The lipid extract of the marine sponge Luffariella cf. variabilis from Mayotte (Indian Ocean) has proven to be an extraordinarily rich source of a wide variety of unusual steroids belonging to the 5α,8α-epidioxy sterol family. Ten epidioxy sterols have been identified: 5α,8α-epidioxycholesta-6,22-dien-3β-ol, 5α,8α-epidioxycholest-6-en-3β-ol, 5α,8α-epidioxy-24(ξ)-methylcholesta-6,22-dien-3β-ol, 5α,8α-epidioxy-24(S)-methylcholest-6-en-3β-ol and its epimer (24R), 5α,8α-epidioxy-24(S)-ethylcholesta-6,22-dien-3β-ol and its epimer (24R), 5α,8α-epidioxy-24(S)-ethylcholest-6-en-3β-ol and its epimer (24R), along with 5α,8α-epidioxy-24(ξ)-methylcholesta-6,9(11),22-trien-3β-ol. Their structures were determined by nuclear magnetic resonance ( 1 H, 13 C) and electron impact mass spectrometry. The mixture of the 10 steroids showed inhibitive activity against the human T-cell leukemia/lymphotropic virus type I (HTLV-I) and also displayed cytotoxic activity against the human breast cancer cell line (MCF 7 WT).Key words: Luffariella cf. variabilis, marine sponge, 5α,8α-epidioxy sterols, antitumor and antiviral activities.Résumé : L'extrait lipidique de l'éponge marine Luffariella cf. variabilis de Mayotte (Océan Indien) s'est révélé être une source extraordinairement riche d'une grande variété de stéroïdes particuliers appartenant à la famille des 5α,8α-épidioxy stérols. Dix épidioxy stérols ont été identifiés: 5α,8α-épidioxycholesta-6,22-dien-3β-ol, 5α,8α-épidioxycholest-6-en-3β-ol, 5α,8α-épidioxy-24(ξ)-methylcholesta-6,22-dien-3β-ol, 5α,8α-épidioxy-24(S)-methylcholest-6-en-3β-ol et son épimère (24R), 5α,8α-épidioxy-24(S)-ethylcholesta-6,22-dien-3β-ol et son épimère (24R), 5α,8α-épidioxy-24(S)-ethylcholest-6-en-3β-ol et son épimère (24R), ainsi que le 5α,8α-épidioxy-24(ξ)-methylcholesta-6,9(11),22-trien-3β-ol. Leurs structures ont été déterminées par résonance magnétique nucléaire ( 1 H, 13 C) et par spectrométrie de masse en impact électronique. Le mélange des 10 stéroïdes a montré une activité inhibitrice sur le virus de la leucémie-lymphome à cellules-T humain de type I (HTLV-I) et possède également une activité cytotoxique sur les cellules cancéreuses humaines du sein (MCF 7 WT).Mots clés : Luffariella cf. variabilis, éponge marine, 5α,8α-épidioxy stérols, activités antitumorale et antivirale. Gauvin et al. 992

The I3C chemical shifts and a large collection of coupling constants have been measured for 169 N-substituted azoles with no other substituents on the ring. Simple additive models have been used to discuss both the chemical shifts and the coupling constants. The chemical shift of the substituent depends on the nature of the azole which can, accordingly, be classified into three to six families. Some structural problems (ringchain isomerism of 1-trifluoromethylsulphonyl-1,2,3-triazole, silylotropy and stannotropy) are also discussed.

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Two new triterpenoid saponins, glinosides A and B, isolated from the aerial parts of Glinus oppositifolius, have been characterized by 1D, 2D, NMR and high-resolution mass spectral (HRMS) techniques. Their structures were established respectively as 16-O-(beta-arabinopyranosyl)-3-oxo-12,16 beta,21 beta,22-tetrahydroxyhopane for glinoside A and 16-O-(beta-arabinopyranosyl)-3-oxo-12,16 beta,22-trihydroxyhopane for glinoside B. Results presented evidence that fractions had a better antiplasmodial activity (IC50 = 31.80 micrograms/ml) than pure glinoside A (IC50 = 42.30 micrograms/ml).

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