五味子素类抑制HIV活性的三维定量构效关系研究

建立了五味子活性成分木脂素类和联苯类化合物抑制HIV活性的三维定量构效 方程。采用联苯环原子和苯环质心两种叠合方式，并区分联苯化合物的不同构型， 共建立了四类CoMSIA模型，其中训练集中联苯类为S构型并叠合联苯环原子建立的 CoMSIA模型相关性最好，交叉验证相关系数q~2为0.71，非交叉验证相关系数r~2 = 0.99，标准偏差SE = 0.051, F = 1000.6。CoMSIA方法采用Gaussian函数计算 场能，并在CoMFA方法的立体和静电场基础上加入疏水场，PLS分析结果更为准确。 该模型三维等势图证实了某些结构和活性规律，如联苯基共面性越好，活性越高， 同时给出了苯环上取代基的体积、电性和疏水性要求，为该类化合物的结构改造提 供了依据。

3D-QSAR Study of schizandrins for Anti-HIV Using Comparative Molecular Similarity Indices Analysis

The present study constructs a model of three-dimensional quantitative structure and bioactivity of anti-HIV for a Chinese traditional medicine-Schizandrins, by implementing a new 3D-QSAR technique: comparative molecular similarity indices analysis (CoMSIA). Here four models are built based on different form of biphenyl and two aligned methods. The results of PLS analyses indicate that a good 3D-QSAR model can be obtained if biphenyl prefers S form and all the compounds are aligned according to the atoms in biphenyl group. After field expressions in terms of similarity indices in CoMSIA instead of the conventionally used Lennard-Jones and Coulomb-type potentials in CoMFA, the cross-validated q 2 and predictive ability are significantly improved. The CoMSIA coefficient contour plots identify several key features that the torsion angel of two benzene planes is a critical factor for the activity and the substituent at cyclooctadiene is also related to the activity, which are very valuable for designing and optimizing new active structures.