O'Mathúna D P, Doskotch R W
Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, Ohio State University, Columbus 43210-1291.
J Nat Prod. 1994 Jun;57(6):767-75. doi: 10.1021/np50108a013.
Four new labdane diterpenes, amoenolide A [1] and its 19-acetate [2], 6-acetate [3], and 6,19-diacetate [4], were isolated from the above-ground parts of Amphiachyris amoena and their structures established by spectral and chemical methods. High-field 1H- and 13C-nmr assignments were made for each compound using 1D and 2D nmr techniques including 1H single-frequency spin-coupling and nOe difference experiments, one-bond and long-range carbon-hydrogen correlations, and the INADEQUATE carbon-carbon connectivity experiment. The absolute stereochemistry was established by the Horeau partial-resolution chemical method with amoenolide A and racemic 2-phenylbutyric anhydride, and by the cd exciton splitting physical method on the synthetic amoenolide A 2-acetate 6,19-dibenzoate [9].
从优美两栖菊（Amphiachyris amoena）的地上部分分离出4个新的半日花烷型二萜，即香茶菜内酯A [1]及其19-乙酸酯[2]、6-乙酸酯[3]和6,19-二乙酸酯[4]，并通过光谱和化学方法确定了它们的结构。使用一维和二维核磁共振技术，包括1H单频自旋耦合和核Overhauser效应（nOe）差异实验、一键和远程碳氢相关以及异核多量子相干（INADEQUATE）碳-碳连接性实验，对每个化合物进行了高场1H和13C核磁共振归属。通过Horeau部分拆分化学方法，使用香茶菜内酯A和外消旋2-苯基丁酸酐，以及通过对合成的香茶菜内酯A 2-乙酸酯6,19-二苯甲酸酯[9]进行圆二色激子分裂物理方法确定了绝对立体化学。
