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In this paper the determination of taxol and the related compounds 10-deacetyltaxol, cephalomannine and 10-deacetylcephalomannine in various parts of Taxus cuspidata Sieb et Zucc. is reported. All four compounds were well separated on a 5 μm Spheri-5 RP-18 column with a mobile phase composed of water:acetonitrile:tetra-hydrofuran (55:35:10). The concentrations of these compounds are quite different for different parts of the plant and are highest in stem bark. Furthermore, the content is related to the age of the plant, the older plants containing larger quantities of taxane diterpenoids. We have also found that the contents of taxol and related compounds in the shrub are usually higher than those in the tree.

Two new bicyclic taxane diterpenoids, taxachitrienes A(1) and B(2), were isolated from the needles of Taxus chinensis. Their structure were elucidated on the basis of spectroscopic data. The crystal structure of 2 was also presented. It is the first time for the isolation of bicyclic diterpenoid which is proposed as the biogenetic precursor for taxanes.

Various 2-amido docetaxel analogues were prepared and evaluated for their cytotoxicities. Among them, m-methoxy and m-chlorobenzoylamido analogues were most active but not superior to docetaxel and paclitaxel, and D-seco analogues inactive. Change of 2-benzoate to 2-benzamide may not improve their activities to drug-resistant cell lines.

Bioassay-guided fractionation of 95% EtOH extract from the roots of Dipsacus asper lead to the isolation of some phenolic acids (caffeic acid, 2,6-dihydroxycinnamic acid, vanillic acid, 2′-O-caffeoyl-D-glucopyranoside ester, and caffeoylquinic acid) as the major active components, and five new iridoid glucoside dimers (1—5) and one new iridoid glucoside monomer (6), other known iridoid glycosides loganin, cantleyoside, triplostoside A, lisianthioside, 6′-O-β-D-apiofuranosyl sweroside, as well as triterpenoids oleanic acid and akebiasaponin D. The structures of new compounds 1—6 were determined as dipsanosides C (1), D (2), E (3), F (4), G (5), and 3′-O-β-D-glucopyranosyl sweroside (6) by spectroscopic, including 1D and 2D NMR techniques, and chemical methods.