Institute for Materials Research, Tohoku University, Katahira, Aoba-Ku, Sendai, Japan.
J Phys Chem B. 2012 Dec 6;116(48):14029-39. doi: 10.1021/jp3098044. Epub 2012 Nov 28.
The inclusion complex formation ability between CB[n] (n = 6-9) and Pt-drugs (oxaliplatin, nedaplatin, carboplatin, and cisplatin) in gas phase as well as water phases has been investigated using the using density functional theory. The results reveal the existence of several stable inclusion complexes in aqueous solution with high solvation energies compared to the guest and host molecule. It has been shown that the formation of complexes between CB[6] and Pt-drugs resulted in structural change in the CB[6], with the calculated deformation energies being higher for the inclusion complexes. The inclusion complexes are stabilized by the hydrogen bonding and the charge transfer between the Pt-drugs and the CB[n] host. Calculated enthalpy and Gibbs free energy of formation in aqueous solution revels that the formation of CB[7]-oxaliplatin is spontaneous, and hence its experimental synthesis is feasible. Among the CB's studied, CB[8]-Pt-drug inclusion complexes have exothermic enthalpy and low Gibbs free energy of formation. Computed (1)NMR spectra in CB[7]-oxaliplatin showed high chemical shielding for the cyclohexane ring, indicating the existence of charge transfer in the inclusion complex. The amine protons in the guest Pt-drugs are shielded due to the hydrogen bonding interaction with CB's oxygen portal.
使用密度泛函理论研究了 CB[n]（n = 6-9）与铂类药物（奥沙利铂、奈达铂、卡铂和顺铂）在气相和水相中的包合络合形成能力。结果表明，在水溶液中存在几种稳定的包合络合物，与客体和主体分子相比具有较高的溶剂化能。结果表明，CB[6]与铂类药物形成的配合物导致 CB[6]的结构发生变化，计算得到的变形能对于包合络合物更高。包合络合物通过 Pt 药物和 CB[n]主体之间的氢键和电荷转移而稳定。在水溶液中计算得到的形成焓和吉布斯自由能表明，CB[7]-奥沙利铂的形成是自发的，因此其实验合成是可行的。在所研究的 CB 中，CB[8]-Pt 药物包合络合物具有放热焓和低形成吉布斯自由能。在 CB[7]-奥沙利铂中计算的（1）NMR 谱显示环己烷环的高化学位移，表明包合络合物中存在电荷转移。由于与 CB 氧门的氢键相互作用，客体 Pt 药物中的胺质子受到屏蔽。
