Ram Kumar A, Selvaraj S, Vickram A S, Sheeja Mol G P, Awasthi Shikha, Thirunavukkarasu M, Selvaraj Manickam, Basumatary Sanjay
Department of Biotechnology, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha University, Chennai 602105, Tamil Nadu, India.
Department of Physics, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha University, Chennai 602105, Tamil Nadu, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2025 Feb 15;327:125349. doi: 10.1016/j.saa.2024.125349. Epub 2024 Oct 28.
This study characterizes the steroidal saponin diosgenin by theoretical and experimental spectroscopic techniques. Theoretical simulations were performed using the DFT/B3LYP/6-311++G(d,p) basis set to simulate spectroscopic, structural and other properties. Optimized geometries from simulations and experiments showed strong agreement, with R value of 0.99846 for bond lengths and 0.88092 for bond angles. Vibrational spectra revealed distinctive peaks for the methyl, methylene, and methine groups in diosgenin. Solvent-solute interactions on the Frontier Molecular Orbitals (FMO), Molecular Electrostatic Potential (MEP) surfaces, and electronic spectra were analyzed, revealing insights into diosgenin's behavior in different environments. The FMO energy gap shows that polar solvents like acetone, ethanol, and water have wider band gaps (6.22-6.23 eV) than non-polar solvents like benzene, chloroform, and toluene (6.17-6.20 eV), indicating stronger interactions with polar groups, enhanced stability, and reduced reactivity. NBO analysis shows substantial stabilization energy (14.71 kJ/mol) when electrons from oxygen's (O) lone pair are donated to the anti-bonding orbital of OC through the transition of LP (2) → σ*. The carbon (C) situated between oxygen (O) and (O) exhibits increased electronegativity (-1.65605 e), confirming the electronegativity of the oxygen atoms. Hirshfeld surfaces shows that the crystal structure is mainly influenced by H…H (90.7 %) interaction. Topological analyses revealed molecular interactions and chemical bonding within diosgenin, highlighting its diverse chemical functionalities. Furthermore, molecular docking and ADME predictions underscores diosgenin's potential biological activity against human hexokinase (-8.09 kcal/mol) and phosphofructokinase (-8.35 kcal/mol), suggesting its efficacy as an antitumor drug.
本研究通过理论和实验光谱技术对甾体皂苷元薯蓣皂苷元进行了表征。使用DFT/B3LYP/6-311++G(d,p)基组进行理论模拟，以模拟光谱、结构和其他性质。模拟和实验得到的优化几何结构显示出高度一致性，键长的R值为0.99846，键角的R值为0.88092。振动光谱揭示了薯蓣皂苷元中甲基、亚甲基和次甲基基团的独特峰。分析了前沿分子轨道（FMO）、分子静电势（MEP）表面和电子光谱上的溶剂-溶质相互作用，揭示了薯蓣皂苷元在不同环境中的行为。FMO能隙表明，丙酮、乙醇和水等极性溶剂的带隙（6.22 - 6.23 eV）比苯、氯仿和甲苯等非极性溶剂（6.17 - 6.20 eV）更宽，这表明与极性基团的相互作用更强、稳定性增强且反应性降低。NBO分析表明，当氧（O）孤对电子通过LP(2)→σ*跃迁捐赠给OC的反键轨道时，会有大量的稳定化能（14.71 kJ/mol）。位于氧（O）和（O）之间的碳（C）表现出增加的电负性（-1.65605 e），证实了氧原子的电负性。Hirshfeld表面表明晶体结构主要受H…H（90.7%）相互作用的影响。拓扑分析揭示了薯蓣皂苷元内的分子相互作用和化学键，突出了其多样的化学功能。此外，分子对接和ADME预测强调了薯蓣皂苷元对人己糖激酶（-8.09 kcal/mol）和磷酸果糖激酶（-8.35 kcal/mol）的潜在生物活性，表明其作为抗肿瘤药物的功效。
