五种新的倍半萜,(4S,5S,6S,7S,8R)-5,6-二羟基-1-乙酰氧基-10(14)-烯丙内酯(1),(4S,5R,6S,7S,8R)-5,6-二羟基-1-乙酰氧基-10(14)-烯丙内酯(2),6-O-丙酰基-英兰内酯(3),1β-羟基-3α-乙酰氧基-11(13)-en-12,8β-内酯(4)和1β,5β-二羟基Eudesma-11(13)-en-12,8β-内酯(5),与12种已知的花一起,从pentanemabritannicum(L.)D.古特。Larr.其中,化合物1和2是立体异构体,属于1,10-seco-eudesmane倍半萜,在C-10和C-14之间具有罕见的双键。通过各种光谱方法阐明了分离化合物的结构,包括1D和2DNMR实验。
Five new sesquiterpenoids, (4S, 5S, 6S, 7S, 8 R)-5,6-dihydroxy-1-acetoxy-10(14)-en-britannilactone (1), (4S, 5 R, 6S, 7S, 8 R)-5,6-dihydroxy-1-acetoxy-10(14)-en-britannilactone (2), 6-O-propionyl-britannilactone (3), 1β-hydroxy-3α-acetoxyeudesma-11(13)-en-12,8β-olide (4) and 1β,5β-dihydroxyeudesma-11(13)-en-12,8β-olide (5), along with twelve known ones were isolated from the flowers of Pentanema britannicum (L.) D.Gut.Larr. Among them, compounds 1 and 2 were stereoisomers which belong to 1,10-seco-eudesmane
sesquiterpenoid with rare double bond between C-10 and C-14. The structures of the isolated compounds were elucidated by various spectroscopic methods, including 1D and 2D NMR experiments.