Isolation, characterization and DFT studies of epoxy ring containing new withanolides from Withania coagulans Dunal.

A new withanolide named as withacoagulin J (1) along with a known withanolide H (2) from Withania coagulans Dunal are reported in this paper. The isolated compounds were elucidated by using 1D-NMR (H NMR, C NMR) and 2D-NMR including homonuclear (COSY, NOESY) and heteronuclear (HSQC, HMBC); along with Mass spectrometry, UV-Visible and IR spectroscopic techniques. The molecular formula based on Fast-Atom Bombardment Mass Spectrometry [FAB-MS (M + 1)] for 1 and 2 were deduced as CHO and CHO with m/z values 453.