Schmidt TJ
Institut fur Pharmazeutische Biologie der Heinrich-Heine-Universitat Dusseldorf, Universitatsstrasse 1, D-40225 Dusseldorf, Germany.
J Nat Prod. 1999 May;62(5):684-7. doi: 10.1021/np980382a.
Three novel seco-prezizaane sesquiterpenes (1-3) were isolated from leaves of Illicium parviflorum (swamp star anise, yellow star anise), a species occurring endemically in central Florida. Compound 1, named cycloparvifloralone, possesses a hitherto unknown ring system with a cagelike acetal/hemiketal structure. Lactones 2 (cycloparviflorolide) and 3 (parviflorolide) which were obtained as an inseparable mixture, coexist in a hemiketal/keto equilibrium. It could be shown that a 4,7-hemiketal (4) occurs in an analogous fashion to pseudoanisatin 5, a known constituent of other Illicium species. From the fruits of Illiciumfloridanum the novel ortholactone 6 was isolated. The structures of the new compounds were elucidated by interpretation of their 1D and 2D homo- and heteronuclear NMR spectroscopic data. The modes of cyclization observed in 1, 2, 4, and 6 have not been described previously, and a biogenetic sequence is proposed for these compounds and further seco-prezizaane sesquiterpenes.
从佛罗里达州中部特有的小花八角（沼泽八角、黄八角）的叶子中分离出三种新型开环-prezizaane倍半萜（1-3）。化合物1名为环小花八角酮，具有一种迄今未知的带有笼状缩醛/半缩酮结构的环系。内酯2（环小花八角内酯）和3（小花八角内酯）以不可分离的混合物形式获得，它们以半缩酮/酮平衡共存。结果表明，4,7-半缩酮（4）的存在方式与其他八角属物种的已知成分伪莽草酸5类似。从小花八角的果实中分离出新型原内酯6。通过对其一维和二维同核和异核核磁共振光谱数据的解析，阐明了新化合物的结构。在化合物1、2、4和6中观察到的环化模式此前尚未有描述，并且为这些化合物以及其他开环-prezizaane倍半萜提出了生源序列。
