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Biomedical subjects

W W Ma

Publications and source records attributed to W W Ma.

9 recordsLinked to original sources
PubMed1992

Biologically active gamma-lactones and methylketoalkenes from Lindera benzoin.

Brine shrimp lethality-directed fractionation of the 95% EtOH extract of ripe berries from Lindera benzoin led to the isolation of three new C21 alkane-alkene gamma-lactones designated isolinderanolide, isolinderenolide, and linderanolide as well as the known series of C17 and C19 obtusilactones (isoobtusilactone A, obtusilactone A, isoobtusilactone, and obtusilactone) previously isolated from Lindera obtusiloba. The novel (6Z,9Z,12Z)-pentadecatrien-2-one, the known (6Z,9Z)-pentadecadien-2-one, and the known (+)-(Z)-nerolidol were also isolated as bioactive compounds. The structural elucidation and biological activities of these compounds are reported.

Animals↗
PubMedDate not supplied

Additional toxic, bitter saponins from the seeds of Chenopodium quinoa.

Quinoa (Chenopodium quinoa) is an important Native American food grain. Prior to consumption, the seeds must be washed with H2O to remove bitterness and improve nutritive value. From the warm-H2O extract of quinoa seeds from Mexico, saponins 1-4 were isolated by monitoring the fractionation with brine shrimp lethality and a taste test for bitterness. By chemical, spectral, and enzymatic methods, 1-4 were identified as glycosides of oleanolic acid. Saponin 4, 3-O-[(beta-D-xylopyranosyl)(1----3)]-beta-D-glucuronopyranosyl-6-O -methyl ester]-oleanolic acid, is a new natural compound.

Animals↗
PubMedDate not supplied

Majorenolide and majorynolide: a new pair of cytotoxic and pesticidal alkene-alkyne delta-lactones from Persea major.

From the EtOH extract of the bark of Persea major, two bioactive compounds, majorynolide [1] and majorenolide [2], were isolated by activity-directed fractionation using brine shrimp. Their structures have been elucidated on the basis of spectral data as a pair of new alkene-alkyne delta-lactones, each with an exocyclic alkylidene methine carbon. Both 1 and 2 are moderately cytotoxic, and 2 is selectively pesticidal.

Animals↗
PubMedDate not supplied

Goniotriol from Goniothalamus giganteus.

The known styrylpyrone, goniotriol, has been isolated from Goniothalamus giganteus. Its bioactivities are reported, and its structure and relative stereochemistry have been determined by X-ray crystallography as 6R-(7R,8R-dihydro-7,8-dihydroxystyryl)-5S,6R-dihydro-5-hydroxy-2-p yrone.

Animals↗
PubMedDate not supplied

Tubulosine: an antitumor constituent of Pogonopus speciosus.

From the antitumor-bioactive sap of Pogonopus speciosus, tubulosine [1] was isolated, by activity-directed fractionation using the brine shrimp lethality test, as the major antitumor constituent. 1H-nmr assignments, obtained from HETCOR and COSY, and X-ray crystallographic results are reported for the first time. Psychotrine [2] was also isolated, and its spectral data are also reported.

Antineoplastic Agents, Phytogenic↗
PubMedDate not supplied

Bioactive neolignans from Endlicheria dysodantha.

From bioactivity-directed fractionation of the EtOH extract of Endlicheria dysodantha, dysodanthin A and dysodanthin B, which are new hexahydrobenzofuranoid neolignans, have been isolated. In addition, the known neolignans, compound 4, which is a burchellin analogue, and megaphone acetate [1] were isolated. All four neolignans showed activities in the brine shrimp lethality test; compounds 1-3 also inhibited the growth of crown gall tumors on potato discs and were cytotoxic to human tumor cells in culture. This is the first report of these neolignans isolated from the genus Endlicheria and of their completely assigned 1H-and 13C-nmr data.

Animals↗