Stigmasterol from the flowers of Peltophorum pterocarpum (DC.) Backer ex K. Heyne (Fabaceae) - Isolation, spectral properties and quantum chemical studies

摘要

Stigmasterol, a biologically potent phytosterol, has been isolated and identified first-time from the flowers of Peltophorum pterocarpum (DC.) Backer ex K. Heyne (Family: Fabaceae) based on detailed spectral studies including 1D- and 2D-NMR. A thorough computational study on the molecular features, vibrational spectra and many other descriptors like HOMO, LUMO, MESP surfaces of the title molecule have been performed. The calculated geometrical parameters are found to be in good harmony with the experimental values. The vibrational modes have been assigned on the basis of potential energy distribution as calculated by VEDA software package and agree well with the corresponding FTIR numbers. Using Gauge independent Orbital method, H-1 NMR and C-13 NMR shifts have been calculated and found to be in good correlation with the experimental results. Global reactivity descriptors and thermodynamic parameters of the molecule have also been calculated.