Lin Bing-Dong, Zhang Chuan-Rui, Yang Sheng-Ping, Zhang Sheng, Wu Yan, Yue Jian-Min
Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, People's Republic of China.
J Nat Prod. 2009 Jul;72(7):1305-13. doi: 10.1021/np900139c.
Sixteen new D-ring-opened phragmalin limonoid orthoesters, swietenitins A-M (1-6, 8, 10, 12-16), 2-acetoxyswietenialide D (7), 2,11-diacetoxyswietenialide D (9), and 11-deoxyswietenialide D (11), and four known compounds were isolated from the twigs of Swietenia macrophylla. The structures of 1-16 were established on the basis of spectroscopic methods, and 1 and 2 were confirmed by single-crystal X-ray diffraction. The (1)H NMR-based conformational analysis on the epimeric compounds 1 and 2 provided a general approach to determine the absolute configuration of the 2,3-epoxy-2-methylbutyryloxy unit at C-3 borne by a large group of the known phragmalin-type limonoid orthoesters.
从大叶桃花心木的嫩枝中分离出16个新的D-环开裂的苦木素类柠檬苦素原酸酯，即苦木素A-M（1-6、8、10、12-16）、2-乙酰氧基苦木内酯D（7）、2,11-二乙酰氧基苦木内酯D（9）和11-脱氧苦木内酯D（11），以及4个已知化合物。通过光谱方法确定了1-16的结构，1和2通过单晶X射线衍射得到证实。基于（1）H NMR对非对映异构体化合物1和2进行的构象分析，为确定一大类已知苦木素型柠檬苦素原酸酯在C-3位上由2,3-环氧-2-甲基丁酰氧基单元所携带的绝对构型提供了一种通用方法。
