Five new pregnane glycosides from the stems of Marsdenia tenacissima.

Activity-guided fractionation of the stems of Marsdenia tenacissima led to the isolation of five new pregnane glycosides, namely marstenacissides E (1), F (2), G (3), H (4), and I (5). Their structures were determined on the basis of (1)H and (13)C NMR, COSY, TOCSY, ROESY, and FABMS experiments.

[Studies on the chemical constituents in vine stem of Bauhinia championii (I)].

Objective: To study the chemical constituents of Bauhinia championii.

Method: Compounds were isolated from the ethanolic extract of B. championii by silica gel column Chromatography, and their structures were elucidated by spectral analyses.

Pregnane glycosides from the stems of Marsdenia tenacissima.

Four new pregnane glycosides, named marstenacissides A (1), B (2), C (3), and D (4), have been isolated from the stems of Marsdenia tenacissima. Their structures were established on the basis of chemical and spectral methods.

Two new bicoumarins from Trifolium repens L.

Two new bicoumarins, named repensin A (1) and B (2), have been isolated from Trifolium repens. On the basis of spectral data, the structures of 1 and 2 have been established as 7-methoxy-7',8'-dihydroxy-8,6'-bicoumarinyl and 7,5'-dihydroxy-3,6'-bicoumarinyl, respectively.