紫杉烷类多药耐药逆转剂的合成及其逆转耐药活性紫杉烷类多药耐药逆转剂的合成及其逆转耐药活性

目的设计合成一系列新型紫杉烷类化合物并进行逆转多药耐药肿瘤细胞耐药活性的筛选。方法以本所生物合成的紫杉烷，Sinenxan A为原料，合成了10个(I_1～7, II_1,2, III)新的紫杉烷类化合物，其结构经FABMS，2DNMR确证，并对多药耐药癌细胞进行了逆转耐药性的试验。结果9个(I_2～7,II_1,2,III)化合物对多药耐药的人口腔上皮癌细胞KB/V200，能够显著逆转其耐药性，增强抗癌药的活性，其中化合物I₂, I₃, I₄逆转活性明显好于已知对照药Verapamil。结论紫杉烷类化合物作为多药耐药逆转剂有较好的逆转耐药活性，值得进一步研究。

Synthesis and drug resistant reversal activities of taxane-like multi-drug resistant reversal agents

AIM: To design and synthesize a series of new taxoids with a 5-O-sidechain, and to test the multi-drug resistant reversal activity of these compound on KB/V200 cells which is 180 times more resistant to vincristine. METHODS: Using Sinenxan A as a common synthetic starting material, three different types of 5-O-sidechain molecules were synthesized through different route. For type I compounds, 14-acetoxy of Sinenxan A was selectively removed by hydrolysis, xanthation and reduction with tributyltin; A C-10-oxo group was introduced by PCC oxidation; 5-O-acetyl group was selectively removed by potassium tert-butoxide and finally the side chain was introduced by acylating with the corresponding acid. For type II compounds, 5-O-sidechain was introduced to the 5-deacetyl Sinenxan A which was obtained by selective hydrolysis with tBuOK. For type III compounds, 9-acetoxy group was introduced, then 5-OH was left free by thorough hydrolysis and reacetylation. Acylation at 5-position, the final product was obtained. Structure of the compounds have been confirmed by FABMS and 2DNMR. The activity of the compounds in vitro was tested on KB/V200 resistant cell line using MTT method. RESULTS: Nine compounds showed resistant reversal activity and enhancing the cytotoxicity of vicristine against KB/V200 cells. Compounds I2, I3, I4 restored the sensitivity of KB/V200 towards vicristine to a level of IC50 at 1 x 10(-8) mol.L-1 which is better than the positive control Verapamil. CONCLUSION: The drug resistant reversal activity of taxane derivatives can be affected by substitution at different positions and the length of side chains of Sinenxan A. It is worthy to be further studied.