Four new minor taxanes from cell cultures of Taxus chinensis

Abstract

Four new minor taxanes (1–4) have been isolated from Ts-19 cell cultures of Taxus chinensis together with five known taxanes (5–9) by silica gel chromatography combined with semi-preparative HPLC chromatography. On the basis of the analyses of the chemical and spectroscopic (IR, MS, 1D, and 2D NMR) data, the structures of new compounds were elucidated as 5α-hydroxy-2α,10β-diacetoxy-14β-(3-hydroxy-2-methyl-butyryl)oxytaxa-4(20),11-diene (1), 2α,5α,10β-triacetoxy-14β-(2-hydroxy-propionyl)oxytaxa-4(20),11-diene (2), 2α,5α,10β-triacetoxy-14β-(2-hydroxy-3-methyl-butyryl)oxytaxa-4(20),11-diene (3), and 2α-benzoxy-4α,9α,10β,13α-tetraacetoxytax-11-ene (4), respectively. Compounds 1–5 were pharmacologically evaluated for their cytotoxicities against five human cancer cell lines (HCT-8, Bel-7402, BGC-823, A549, and A2780) and their reversing activity towards multi-drug resistance A549/taxol tumor cell line, and the results showed that all of the tested compounds exhibited very low cytotoxicities, while compound 4 possessed twice the reversing activity as that of verapamil at 10 μM.

Keywords:

• taxane
• MDR reversing activity
• cell cultures
• Taxus chinensis

Acknowledgements

This work was supported by the National Natural Science Foundation of China (Grant No. 30572243), Beijing Natural Science Foundation (Grant No. 7062048), and the Program for New Century Excellent Talents in University (NCET-06-0155).