Novel seco-phenanthroquinolizidine alkaloids from Indonesian Boehmeria virgata

Two novel seco-phenanthroquinolizidine alkaloids, (− )-(14aR,15R)-hydroxyjulandine (1) and (+)-(S)-3-O-des- methyljulandine (2), together with eleven known compounds (3–13) were isolated from the leaves of Indonesian Boehmeria virgata. The structures of these compounds were assigned based on the interpretation of 1D/2D NMR and HRMS data. The absolute configurations of seco-phenanthroquinolizidines 1 and 2 were determined from their ECD spectra by comparison with the known phenanthroquinolizidine 3. The isolated seco-phena- throquinolizidines 1–3 were evaluated for antiproliferative activity against five tumor cell lines. Compound 3 exhibited potent cytotoxic activity, while 1 and 2 were not active against all tested cell lines.