Li Ya-Wen, Feng Rui-Zhi, Li Xiao-Jiang, Liu Ai-Chuan, Wang En-Lin
School of Earth and Environment, Anhui University of Science and Technology, Huainan 232001, China.
School of Safety and Emergency Management Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, China.
Molecules. 2025 Jul 25;30(15):3115. doi: 10.3390/molecules30153115.
In order to explore the essence of the anticoccidiosis of anticoccidial drugs under bioelectric currents, the intermolecular double-proton transfer and conformational transformation of 4-pyridone-3-carboxylic acid were investigated by quantum chemistry calculations (at the M06-2X/6-311++G**, M06-2X/aug-cc-pVTZ and CCSD(T)/aug-cc-pVTZ levels) and finite temperature string (FTS) under external electric fields. The solvent effect of HO on the double-proton transfer was evaluated by the integral equation formalism polarized continuum model. The results indicate that the influences of the external electric fields along the direction of the dipole moment on double-proton transfer are significant. The corresponding products are controlled by the direction of the external electric field. Due to the first-order Stark effect, some good linear relationships form between the changes of the structures, atoms in molecules (AIMs) results, surface electrostatic potentials, barriers of the transition state, and the external electric field strengths. From the gas to solvent phase, the barrier heights increased. The spatial order parameters (, ) of the conformational transformation could be quickly converged through the umbrella sampling and parameter averaging, and thus the free-energy landscape for the conformational transformation was obtained. Under the external electric field, there is competition between the double-proton transfer and conformational transformation. The external electric field greatly affects the cooperativity transfer, while it has little effect on the conformational transformation. This study is helpful in the selection and updating of anticoccidial drugs.
为了探究抗球虫药物在生物电流作用下抗球虫的本质，通过量子化学计算（在M06 - 2X/6 - 311++G**、M06 - 2X/aug - cc - pVTZ和CCSD(T)/aug - cc - pVTZ水平）以及外部电场下的有限温度弦（FTS）研究了4 - 吡啶酮 - 3 - 羧酸的分子间双质子转移和构象转变。采用积分方程形式极化连续介质模型评估了HO对双质子转移的溶剂效应。结果表明，沿偶极矩方向的外部电场对双质子转移的影响显著。相应产物受外部电场方向控制。由于一级斯塔克效应，结构变化、分子中的原子（AIMs）结果、表面静电势、过渡态能垒与外部电场强度之间形成了一些良好的线性关系。从气相到溶剂相，能垒高度增加。通过伞形采样和参数平均可以快速收敛构象转变的空间序参量（，），从而得到构象转变的自由能景观。在外部电场作用下，双质子转移和构象转变之间存在竞争。外部电场极大地影响协同转移，而对构象转变影响较小。本研究有助于抗球虫药物的选择和更新。
