Santos J R C, Abreu P E, Marques J M C
CQC-IMS, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal.
Phys Chem Chem Phys. 2023 Jul 26;25(29):19899-19910. doi: 10.1039/d3cp00096f.
This work reports a thorough molecular dynamics investigation on the aggregation patterns of curcumin and piperine in water, ethanol and a mixture of both solvents. The low solubility of curcumin in water results in a rapid formation of very stable dimers for both keto and enol tautomers. In agreement with a higher solubility, piperine molecules move closer and farther apart several times during the simulation, which indicates the formation of a less stable dimer in water. In contrast, both curcumin and piperine are soluble in ethanol and, thus, dimers can hardly be formed in this media. In comparison with a pure-water solvent, a 30 : 70 mixture of ethanol and water significantly reduces the probability of formation of most dimers of curcumin and piperine molecules. The simulations show that larger clusters may be complex structures, but the formation of stacks (in the case of piperine and enol tautomer of curcumin) and cages (when the keto tautomer of curcumin is involved) are not rare. Furthermore, it is shown that each single molecule presents a certain degree of mobility in the cluster, especially on the surface, but without leading to dissociation.
这项工作报道了对姜黄素和胡椒碱在水、乙醇以及两种溶剂混合体系中聚集模式的全面分子动力学研究。姜黄素在水中的低溶解度导致其酮式和烯醇式互变异构体都能快速形成非常稳定的二聚体。与较高的溶解度一致，在模拟过程中胡椒碱分子多次靠近和远离，这表明在水中形成了稳定性较差的二聚体。相比之下，姜黄素和胡椒碱都可溶于乙醇，因此在这种介质中几乎不会形成二聚体。与纯水溶剂相比，乙醇和水的30∶70混合物显著降低了姜黄素和胡椒碱分子形成大多数二聚体的概率。模拟结果表明，较大的聚集体可能是复杂结构，但堆积结构（如胡椒碱和姜黄素烯醇式互变异构体的情况）和笼状结构（当涉及姜黄素酮式互变异构体时）并不罕见。此外，研究表明每个单分子在聚集体中都具有一定程度的流动性，尤其是在表面，但不会导致解离。
