Two new C(13) nor-isoprenoids from the leaves of Casearia sylvestris

Two new C(13) nor-isoprene glycosides, (6S,9S)-6,9-dihydroxymegastiman-4-en-9-O-beta-D-glucopyranoside (1) and (6S,9S)-6,9-dihydroxymegastiman-4-en-9-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside (2) were isolated from the leaves of Casearia sylvestris, along with icariside B(5) (3), byzantionoside B (4), blumenol B (5), blumenol C (6) and loliolide (7). The structures of these compounds were determined on the basis of 1D and 2D NMR, MS and circular dichroism (CD) spectroscopic analyses, chemical methods and comparison with the literature data.