从富宁藤中得到的两类新的强心苷以及它们之间的可能的生源转化途径

Five novel cardiac glycosides with two types of unusual aglycone [funingenin A (2a) and B], named funingenosides E-I (2-6), together with a known compound, funingenoside B (1), were isolated from the aerial part of Parepigynumfuningense Tsiang et P. T. Li (Apocynaceae). The structures of 2-6 were elucidated by means of MS, IR, NMR spectral analyses and chemical degradation. The possible biogenetic pathway of the two types of cardiac glycosides was also discussed.