三裂蟛蜞菊中的倍半萜内酯成分及其化感作用

Allelopathic Sesquiterpene Lactones from Wedelia trilobata

摘要:

从外来种三裂蟛蜞菊(Wedeliatrilobata)的全株中分离得到6个倍半萜内酯化合物,通过光谱分析,分别鉴定为6-异丁酰基-三叶拉色芹内酯(1)、1β-acetoxy-4α,9α-dihydroxy-6β-isobutyroxyprostatolide(2)、1β,9α-diacetoxy-4α-hydroxy-6β-isobutyroxyprostatolide(3a)、1β,9α-diacetoxy-4α-hydroxy-6β-methacryl-oxyprostatolide(3b)、1β,4α-dihydroxy-9α-tigloyloxy-6β-methylpropanoylprostatolide(4a)、9α-angeloyloxy-1β,4α-dihydroxy-6β-methylpro-panoylprostatolide(4b)。除1和3a外,其余4个化合物均是首次从该植物中得到。通过种子萌发和幼苗生长抑制试验发现化合物1、2、3a和3b的混合物以及4a和4b的混合物对萝卜、小白菜和西红柿的幼苗生长有较强的抑制作用。4a和4b的混合物对咸水虾有较高的毒性。

Abstract:

Six sesquiterpene lactones were isolated from the whole plant of Wedelia trilobata (Compositae). On the basis of spectral data, the structures of these constituents were identified as trilobolide-6-O-isobutyrate (1), 1β-acetoxy - 4α, 9α-dihydroxy - 6β- isobutyroxyprostatolide (2), 1β, 9α- diacetoxy- 4α- hydroxy - 6β- isobuty-roxyprostatolide (3a), 1β, 9α-diacetoxy- 4α-hydroxy- 6β-methacryloxyprostatolide (3b), 1β, 4α-di hydroxy - 9α-tigloyloxy-6β-methylpropanoylprostatolide (4a), and 9α-angeloyloxy-1β，4α-dihydroxy-6β-methylpropanoyl-prostatolide(4b)．All compounds except 1 and 3a were isolated from this plant for the first time．Compounds 1，2，a mixture of 3a and 3b， and a mixture of 4a and 4b exhibited potent growth inhibitory effect on the seedlings of radish，cabbage，and tomato in seed germination and seedling growth inhibition test．The mixture of 4a and 4b showed toxicity to brine shrimp in lethality test.