Kumar Sumit, Wu Lidong, Sharma Neha, Kaushik Kumar, Grishina Maria, Chhikara Bhupendra S, Potemkin Vladimir, Rathi Brijesh
Laboratory for Translational Chemistry and Drug Discovery, Department of Chemistry, Hansraj College University Enclave, University of Delhi Delhi 110007 India
Department of Chemistry, Miranda House, University of Delhi Delhi 110007 India
RSC Adv. 2019 Jul 4;9(36):21031-21041. doi: 10.1039/c9ra02463h. eCollection 2019 Jul 1.
Low-molecular weight organic gelators have been of significant interest in recent years because of their interesting properties and potential applications in sensing technology, biomedicine and drug delivery. Herein, the synthesis, characterization and gelation properties of new oseltamivir conjugates are reported. The oseltamivir-triazole conjugate 1 was synthesized a click-reaction in a 75% yield. The key features of this conjugate include the presence of amide, flexible ester linkages and a triazole scaffold linking a hydrophobic alkyl chain. The conjugate 1, possessing a long alkyl chain, showed gelation properties in various apolar organic solvents. This gelation behavior was not observed in the case of the deesterified conjugate 2; this indicated the necessity of the alkyl chain for gelation. The gelator 1 showed thermoreversible gelation properties in a range of linear alkane solvents (from -pentane to -dodecane). A scanning electron microscopic study suggests that the gelator 1 exists as cross-linked structures, which are self-aggregated in the range of submicrometers, as supported by extensive H-NMR studies. The rheological parameters supported the occurrence of a soft gelation process, and the gel formed in -decane was found to be stiffer than that formed in -hexane. Computational studies suggested that the gelation behavior was indeed due to micelle formation and dependent on the lipophilicity of solvents.
近年来，低分子量有机凝胶剂因其有趣的性质以及在传感技术、生物医学和药物递送方面的潜在应用而备受关注。在此，报道了新型奥司他韦缀合物的合成、表征及凝胶化性质。奥司他韦 - 三唑缀合物1通过点击反应合成，产率为75%。该缀合物的关键特征包括酰胺的存在、柔性酯键以及连接疏水烷基链的三唑骨架。具有长烷基链的缀合物1在各种非极性有机溶剂中表现出凝胶化性质。在脱酯缀合物2的情况下未观察到这种凝胶化行为；这表明烷基链对于凝胶化的必要性。凝胶剂1在一系列线性烷烃溶剂（从戊烷到十二烷）中表现出热可逆凝胶化性质。扫描电子显微镜研究表明，凝胶剂1以交联结构存在，在亚微米范围内自聚集，大量的氢核磁共振研究支持了这一点。流变学参数支持了软凝胶化过程的发生，并且发现在癸烷中形成的凝胶比在己烷中形成的凝胶更硬。计算研究表明，凝胶化行为确实是由于胶束形成，并且取决于溶剂的亲脂性。
