THE ELECTROTOPOLOGICAL STATE - AN ATOM INDEX FOR QSAR
THE ELECTROTOPOLOGICAL STATE - AN ATOM INDEX FOR QSAR
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DOI：
10.1002/qsar.19910100108
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发表时间：
1991-03-01
期刊：
影响因子：
--
通讯作者：
KIER, LB
中科院分区：
文献类型：
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作者：
HALL, LH;MOHNEY, B;KIER, LB
引入了分子中原子的新表征作为电拓扑状态指数，它结合了分子中每个骨架原子的电子特征和拓扑环境。 骨架原子的电拓扑状态（E-状态）被公式化为内在值 I(i) 加上扰动项 DELTA-I(i)，由分子中每个原子的分子拓扑环境内的电子相互作用产生。 对于第一行原子，原子内在值表示为 I = (delta-v + 1)delta-v 和 delta 分别是分子骨架中原子的价电子和西格玛电子的计数。 原子 i 的 E 状态 S(i) 定义为 S(i) = I(j) + DELTA-I(j)，其中其他原子对原子 i 的影响 DELTA-I(i) 给出为 SIGMA(I(j) - I(j))/r(ij)2； r(ij) 是原子 i 和 j 之间的图间隔，以原子数计，包括 i 和 j。 电拓扑状态的信息通过各种类型的有机结构的例子来揭示，包括骨架分支和杂原子变化。 一系列羰基化合物的 E 态值与 NMR 化学位移的关系得到了证明。 给出了 MAO 的酰肼抑制和 β-咔啉的受体结合的 QSAR 示例。 这些例子揭示了这种使用原子级索引的 QSAR 方法的强大功能，原子级索引直接从分子连接表计算得出，其中可以识别分子中对活动重要的原子和区域。
A new characterization of atoms in molecules is introduced as the electrotopological state index, which combines both the electronic character and the topological environment of each skeletal atom in a molecule. The electrotopological state (E-state) of a skeletal atom is formulated as an intrinsic value I(i) plus a perturbation term DELTA-I(i), arising from the electronic interaction within the molecular topological environment of each atom in the molecule. The atom intrinsic value, for first row atoms, is expressed at I = (delta-v + 1)delta-v and delta are the counts of valence and sigma electrons, respectively, for the atom in the molecular skeleton. The E-state, S(i), for atom i is defined as S(i) = I(j) + DELTA-I(j), where the influence of other atoms on atom i, DELTA-I(i), is given as SIGMA(I(j) - I(j))/r(ij)2; r(ij) is the graph separation between atoms i and j, counted as number of atoms, including i and j. Information in the electrotopological state is revealed by examples of various types of organic structures, including skeletal branching and heteroatom variation. The relation of the E-state value to NMR chemical shift is demonstrated for a series of carbonyl compounds. QSAR examples are given for hydrazide inhibition of MAO and for receptor binding of beta-carbolines. These examples reveal the power of this approach to QSAR using atom level indexes, computed directly from molecule connection tables, in which it is possible to identify atoms and regions in the molecule which are important for activity.