Crepidatumines C and D, Two New Indolizidine Alkaloids from Dendrobium crepidatum Lindl. ex Paxt.
Two new indolizidine alkaloids, crepidatumines C (1) Bar Spoons 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