Phytotoxic Compounds from Xanthocephalum gymnospermoides var. eradiatum1
作者:Isabel Rivero-Cruz、José Luis Trejo、María Isabel Aguilar、Robert Bye、Rachel Mata
DOI:10.1055/s-2000-9783
日期:2000.12
Investigation of the aerial parts of Xanthocephalum gymnospermoides var eradiatum led to the isolation of two new labdane-type of diterpenes, namely, 8α,13S-epoxylabdane-14S,15-diol (1) and methyl grindelate (2). In addition, grindelic acid (3), 7α,8α-epoxygrindelic acid (4), 7α-hydroxy-8(17)dehydrogrindelic acid (5), 17-hydroxygrindelic acid (6) and 4,5-epoxy-β-caryophyllene (7) were obtained. The isolated compounds were characterized by spectral means. The absolute configuration of compound 1 was established by chemical correlation with 8α,13S-epoxy-15-nor-labdan-14-oic acid methyl ester of known absolute stereochemistry and by using the advanced Mosher's ester methodology. The results of the present investigation indicated that the known compound barbatol (8) could be an enantiomer of compound 1. Compounds 1 - 3 and 7 caused significant inhibition of the radicle growth of seedlings of Amaranthus hypochondriacus.
通过对Xanthocephalum gymnospermoides var eradiatum的空中部分进行研究,分离出两种新的腊烷型二萜,即8α,13S-环氧腊烷-14S,15-二醇(1)和甲基格林德酸(2)。此外,还获得了格林德酸(3)、7α,8α-环氧格林德酸(4)、7α-羟基-8(17)脱氢格林德酸(5)、17-羟基格林德酸(6)和4,5-环氧-β-石竹烯(7)。通过光谱手段对分离出的化合物进行了表征。通过与已知的绝对立体化学结构8α,13S-环氧-15-去甲基-腊烷-14-酸甲酯进行化学相关性分析,并利用先进的莫舍尔酯法,确定了化合物1的绝对构型。本研究结果表明,已知化合物barbatol(8)可能是化合物1的对映异构体。化合物1-3和7对Amaranthus hypochondriacus幼苗的胚根生长有显著抑制作用。