Three new biflavonoids from Chinese Dragon's blood, Dracaena cochinchinensis

摘要

Three new biflavonoids, named (2RγS)-3′-methoxy-8- methylsocotrin-4′-ol (1), (2SγR)-3′-methoxy-8-methylsocotrin- 4′-ol (2), and (2RγR)-8-methylsocotrin-4′- ol (3), were isolated from Chinese Dragon's blood [Dracaena cochinchinensis (Lour.) S. C. Chen], together with two known ones. The structures of these new biflavonoids were elucidated by a combination of HR-ESI-MS, ~1H NMR, ~(13)C NMR, HMQC, and HMBC spectra. The absolute configurations of compounds 14 were determined by quantum chemical calculation of the circular dichroism spectrum and comparison with the experimental CD spectrum.