A new sphingolipid and furanocoumarins with antimicrobial activity from Ficus exasperata.

From the methanol extract of the stem bark of Ficus exasperata, a new sphingolipid named Ficusamide, (2S,3S,4R,11E)-2-[(2',3'-dihydroxyhexacosanoylamino)]-11-octadecene-1,3,4-triol (1), along with three known furanocoumarins, (S)-(-) oxypeucedanin hydrate (2), (R)-(+) oxypeucedanin hydrate (3), bergapten (5-methoxypsoralen) and six other known compounds, were isolated. Their structures were characterized basing on spectroscopic methods and chemical evidence. Compounds (1-3) were analyzed for their antimicrobial activity.

New friedelane triterpenoids with antimicrobial activity from the stems of Drypetes paxii.

Two new friedelane-type triterpenes named 12alpha-hydroxyfriedelane-3,15-dione and 3beta-hydroxyfriedelan-25-al, together with six known compounds were isolated from the stems of Drypetes paxii Hutch. (Euphorbiaceae). Their structures were established on the basis of conventional 1 dimensional (1D) NMR methods, 2D shift-correlated NMR experiments and mass spectra.

Triterpenoids with antimicrobial activity from Drypetes inaequalis.

The air-dried stems and ripe fruit of Drypetes inaequalis Hutch. (Euphorbiaceae) were studied. Four triterpene derivatives, characterized as lup-20(29)-en-3beta,6alpha-diol, 3beta-acetoxylup-20(29)-en-6alpha-ol, 3beta-caffeoyloxylup-20(29)-en-6alpha-ol and 28-betad-glucopyranosyl-30-methyl 3beta-hydroxyolean-12-en-28,30-dioate along with 10 known compounds were isolated from the whole stems.

New triterpenoids from the stem barks of Drypetes tessmanniana.

The MeOH extract of the stem barks of Drypetes tessmanniana (Euphorbiaceae) afforded two new triterpene derivatives characterized as 3beta-O-(E)-3,5-dihydroxycinnamoyl-11-oxo-olean-12-ene and 3beta,6alpha-dihydroxylup-20(29)-ene together with seven known compounds. Their structures were established on the basis of spectral analysis.

Synthesis and cytotoxic activity of benzo[a]pyrano[3,2-h] and [2,3-i]xanthone analogues of psorospermine, acronycine, and benzo[a]acronycine.

Condensation of 2-hydroxy-1-naphthalenecarboxylic acid with phloroglucinol afforded 9,11-dihydroxy-12H-benzo[a]xanthen-12-one (6). Construction of an additional dimethylpyran ring onto this skeleton, by alkylation with 3-chloro-3-methyl-1-butyne followed by Claisen rearrangement, gave access to 6-hydroxy-3,3-dimethyl-3H,7H-benzo[a]pyrano[3,2-h]xanthen-7-one (12) and 5-hydroxy-2,2-dimethyl-2H,6H-benzo[a]pyrano[2,3-i]xanthen-6-one (13), which were methylated into 6-methoxy-3,3-dimethyl-3H,7H-benzo[a]pyrano[3,2-h]xanthen-7-one (14) and 5-methoxy-2,2-dimethyl-2H,6H-benzo[a]pyrano[2,3-i]xanthen-6-one (15), respectively. Osmium tetroxide oxidation of 14 and 15 gave the corresponding (+/-)-cis-diols 16 and 17, which afforded the corresponding esters 18-21 upon acylation.

Synthesis and cytotoxic activity of pyranocarbazole analogues of ellipticine and acronycine.

Various 2,2,5,11-tetramethyl- and 2,2,5,6,11-pentamethyl-2,6-dihydropyrano[3,2-b]carbazole derivatives were synthesized by condensation of 3-methylbut-2-enal or 3-chloro-3-methylbut-1-yne with an appropriate hydroxycarbazole. These compounds associate the tricyclic system responsible for the intercalating properties of ellipticine related drugs, with the dimethylpyran pharmacophore of acronycine derivatives. The study of the biological properties of the new pyrano[3,2-b]carbazole derivatives was carried out in vitro on L1210 murine leukaemia cell line.

A new phenylpropanoid ester from the bark of Zanthoxylum scandens (Rutaceae).

The alkaloids norchelerythrine, magnoflorine and (-)(S)-O-methylbalfourodinium cation were isolated from Zanthoxylum scandens bark collected in Vietnam, together with the flavanone glycoside hesperidin and the phenylpropanoids (E)-O-geranylconiferyl alcohol and (E)-O-geranylconiferyl alcohol (9Z, 12Z)-linoleate. This latter is a novel compound whose structure was elucidated on the basis of its spectral data and confirmed by chemical correlation.