Phytochemical investigation of CH2Cl2 crude extract from the roots
of D. velutina led to the isolation of three new pterocarpans, velucarpins
A–C (1–3) together with three known pterocarpans (4–6), (−)-
medicarpin (4) [6], 4-hydroxymedicarpin (5) [7] and (6aR,11aR)-3,8-
dihydroxy-9-methoxypterocarpan (6) [8]. The structures of these iso-
lated pterocarpans were elucidated using spectroscopic methods espe-
cially 1D and 2D NMR spectroscopy and Circular Dichroism (CD) for
the assessment of absolute configuration. The structures of the known
compounds were determined and confirmed by comparison of their 1
H and 13C NMR spectroscopic data with those previously published
data.