New alkaloids from Daphniphyllum himalense

摘要

Nine new Daphniphyllum alkaloids (1-9) and 16 biosynthetically related known ones were obtained during the phytochemical investigation into a Nepalese plant, Daphniphyllum himalense. Structures were assigned to these compounds based on careful spectroscopic interpretation and NMR comparison with literature data. Deuteration of H-2-16 in CD3OD due to quick keto-enol tautomerization was observed for both 2 and 3. The recently reported 3 beta-hydroxydaphniyunnine A was re-examined and its structure was revised to be 21-deoxymacropodumine D via X-ray diffraction analysis. All the isolates were screened preliminarily for their in vitro inhibitory effects against four kinases, PTP1B, aurora A, HDAC6 and IKK-beta, and selective alkaloids exhibited weak activities at 20 mu g mL(-1).