Institute of Photo Biophysics, Physics and Electronics Department, Henan University, 475004, Kaifeng, China.
J Mol Model. 2013 Sep;19(9):3619-26. doi: 10.1007/s00894-013-1894-9. Epub 2013 Jun 9.
A tree-step computational approach has been applied to determine the lowest-energy conformers of luteolin-4'-O-β-D-glucoside (L4'G). Fifty-seven starting structures of the L4'G have been built, and then by performing with density functional theory (DFT) optimizations and second-order Møller-Plesset (MP2) calculations, the preferred conformations of L4'G are predicted. In order to test the accuracy of the computational approach, a hybrid Monte-Carlo multiple minimum (MCMM)/quantum mechanical (QM) approach is applied to determine the favorable conformers of L4'G. The alternative classification is employed to put similar conformations into the same catalogue according to the dihedral angles among the luteolin rings, glycosidic dihedral angles, and the orientations of hydroxyl and hydroxymethyl groups. The low-energy conformations are located after the optimizations at the HF/6-31G(d) and B3LYP/6-311+G(d) levels. Compared with the hybrid MCMM/QM approach, the tree-step computational approach not only remains accurate but also saves a lot of computing resources.
已应用树步计算方法来确定木樨草素-4'-O-β-D-葡萄糖苷（L4'G）的最低能量构象。构建了 57 个 L4'G 的起始结构，然后通过进行密度泛函理论（DFT）优化和二级 Møller-Plesset（MP2）计算，预测了 L4'G 的优先构象。为了测试计算方法的准确性，应用混合蒙特卡罗多最小值（MCMM）/量子力学（QM）方法来确定 L4'G 的有利构象。采用替代分类法，根据木樨草素环、糖苷二面角和羟基及羟甲基基团的取向之间的二面角，将相似构象归入同一目录。在 HF/6-31G(d)和 B3LYP/6-311+G(d)水平进行优化后，找到了低能量构象。与混合 MCMM/QM 方法相比，树步计算方法不仅保持了准确性，而且还节省了大量的计算资源。
