Three new pterocarpans from the aerial parts of Abrus Precatorius

Three new pterocarpans, named abrusprecatins A-C (1-3), along with three known ones, namely medicarpin (4), maackiain (5), and 4-hydroxy-3-methoxy-8,9-methylenedioxypterocarpan (6) were isolated from the aerial parts of Abrus precatorius. The structures of these compounds were established by extensive analysis of mass spectrometric data, 1 D and 2 D NMR spectroscopic data. In addition, the absolute configurations were determined by a combination of single crystal X-ray diffraction analysis and circular dichroism spectroscopy.