Some progress on the chemistry of natural bioactive terpenoids form Chinese medicinal plants

(1) Pseudolaric acids - Novel diterpenes, Pseudolaric acid A, B, C and D were isolated from Pseudolarix kaempferi Gorden (pinaceae). Their structures were assigned by spectroscopic data and chemical correlations. In the contineous studies, the absolute configurations, the conformations in the solutions, the framentation mechanisms of MS and assigments of all NMR spectral signals were also reported. They showed the antifungal and cytotoxic activities. (2) Daphnane diterpenes - In the further studies on the plants of Thymelaeaceae, besides 10 known diterpenes, 16 new daphnane diterpenes were isolated from Daphne genkwa, D. tangutica, D. giraldii, Wikstroemie chamaedaphne. They showed the antifertilities activities. (3) Tripterygium diterpenes 14 new diterpenes were isolated from Triperygium wilfordii, T. regeli and T. hypoglaucum. Some of them showed the antitumor activities. The CD spectra showed that A/B ring of all compoundshave trans configuration as same as tripdiolide and triptolide determined by X-ray diffraction (4) Pregnane glycosides from Marsdenia koi - Two new pregnane glycosides marsdenikoiside A and marsdenikoiside B which can terminate the early pregnancy were isolated from Marsdeia koi. Their structures were elucidated by hydrolysis and spectroscopic methods.

Preliminary study of sex hormones of medical importance in Bangladeshi plants.

Twenty six different Bangladeshi plants of folkloric contraceptive use were screened for their oil content, percent unsaponifiables and steroids particularly estradiol, and estrogenic steroids. The distribution of these parameters were studied in seeds, roots, leaves, barks and whole plants. The oil content ranged between 0.23 and 6.75% being highest in Jasminium sacbac (family : oleaceae) seeds. The unsaponifiables varied from 0.04 to 7.87% showing highest content in Xanthium stamanium (roots), and least in Litsea sebifera (Leaves). All plants tested showed positive Salkowski test. Of all 26 plants screened, Synedrella Nodiflora (whole plant), Heliotropicum indicum (root), Belva chal (Bark) and Phyllanthus neruri (whole plant), showed high content of estradiol. Amongst these four, Heliotropicum indicum root showed highest concentration of estradiol.