贝母辛的结构修正

从川产家种华西贝母(Fritillaria siechuanica)鳞茎中分出贝母辛(peimisine)(碱Ⅲ)。应用光谱法(¹H—¹H,¹³C—¹H COSY,2D—NOE),对文献报告的贝母辛的结构作了修正,并证明FR—5与贝母辛系同一化合物。指出湖贝辛结构的某些错误以及对松贝辛的结构提出怀疑,认为其可能为贝母辛。

REVISION OF STRUCTURE OF PEIMISINE

From the bulbs of Fritillaria siechuanica cultivated in Sichuan province, 5 alkaloids including peimisine (III) were isolated. Structure of peimisine reported in reference (2) was revised as 2 based on 2D-NMR (1H-1H, 1H-13C COSY and NOE), and FR-5 was proved to be peimisine on the basis of their melting point and TLC behavior. It is worthy of noting that 1) configuration of the oxygen at the C-17 in hupehenisine 3 is possibly erroneous; 2) both songbaisine 4 (A or B) and peimisine 2 should be the same compound on the basis of comparison of their 13C NMR data (Table 3) and 1H NMR spectra; 3) configuration of the oxygen atom at C-17 in the jervine-type steroidal alkaloids can not be safely proved by their IR, MS and the chemical shifts of some protons such as the methyls without the X-ray diffraction analysis, or the NOE technique and the 13C NMR method.