Comparative Study of Vibrational Spectra of Two Bioactive Natural Products Lupeol and Lupenone Using MM/QM Method

Table 1

Calculated bond lengths (angstroms) and bond angle (degrees) for lupeol and lupenone, which were optimized at the Oniom (B3LYP/6-31G: PM3) methods.

      Lupeol
Bond lengthsOniom (B3LYP/6-31G: PM3)

(C–C)1.487–1.577
(C=C)1.333
(C–H)1.085–1.133
(C–O)1.415
(O–H)0.952

Bond anglesOniom (B3LYP/6-31G: PM3)

(C–C–C)101.77–115.51
(C–C=C)121.97–122.51
(C–C–H)107.11–112.12
(C–O–H)106.02
(C–C–O)107.61–113.37
(C=C–H)121.22–123.46
(H–C–H)105.341–115.30

      Lupenone
Bond lengthsOniom (B3LYP/6-31G: PM3)

(C–C)1.502–1.580
(C–H)1.098–1.121
(C=O)1.215
(C=C)1.345

Bond anglesOniom (B3LYP/6-31G: PM3)

(C–C–C)101.46–125.97
(C–C–H)104.15–112.67
(C–C=O)120.92–122.47
(H–C–H)104.52–107.26
(C=C–C)120.48–130.21