Seven new dammarane triterpenes from the floral spikes of Betula platyphylla var. japonica
Seven new dammarane-type triterpenoids, including two 20(S)-hydroxy-25-methoxy-dammar-23-enes (1 and 2), two 20(S),24(R)-epoxydammaranes (3 and 4), a cabralealactone (5), and two 20(S),25-epoxydammaranes (6 and 7), together with seven known triterpenes (8–14), were isolated from the floral spikes of Betula platyphylla var. japonica. The structures for all compounds were elucidated by the analyses of extensive spectroscopic data, as well as chemical examinations.
KeywordsBetula platyphylla var. japonica Floral spikes Dammarane triterpene 20,25-Epoxydammarane Betulaceae
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