Two new indolizidine alkaloids, crepidatumines C (1) and D (2), together with crepidine (3), isocrepidamine (4), and crepidamine (5) were isolated from the Dendrobium crepidatum Lindl.ex Paxt.X-ray diffraction experiments established the absolute configurations of known compounds 3 and 4.The planar structures and relative configurations truvisionhealthftp.com of new compounds 1 and 2 were elucidated by extensive spectra analysis including HR-ESI-MS, NMR (1H, 13C, 1H-1H COSY, HSQC, HMBC, and NOESY spectra), read more and the absolute configurations of 1 and 2 were suggested on the basis of possible biosynthetic pathways.
The biological results confirmed that isocrepidamine (4) displayed a potent hypoglycemic effect in vitro without cytotoxicity.