Ndi Chi P, Semple Susan J, Griesser Hans J, Pyke Simon M, Barton Mary D
Sansom Institute, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, Australia.
J Nat Prod. 2007 Sep;70(9):1439-43. doi: 10.1021/np070180r. Epub 2007 Sep 11.
A crude extract from the Australian desert plant Eremophila neglecta has recently been shown to possess antibacterial activity in a survey of candidate plants that may bear novel antimicrobial compounds. Bioassay-directed fractionation of the Et(2)O extract of E. neglecta using a broth microdilution assay led to the isolation of three new serrulatane-type diterpenoids, 2,19-diacetoxy-8-hydroxyserrulat-14-ene (2), 8,19-dihydroxyserrulat-14-ene (3), and 8-hydroxyserrulat-14-en-19-oic acid (4), and a known o-naphthoquinone commonly referred to as biflorin (5). The structures of 2-5 were determined using 1D and 2D NMR, FTIR, and high-resolution mass spectrometry. Compounds 3-5 showed antimicrobial activity against Gram-positive bacteria including Staphylococcus aureus, Streptococcus pyogenes, and S. pneumoniae. The minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) ranged from 6.5 to 101.6 microM and 12.7 to 202.9 microM, respectively. No activity was observed for these compounds against Gram-negative bacteria.
最近，在一项对可能含有新型抗菌化合物的候选植物的调查中，澳大利亚沙漠植物疏花糙苏（Eremophila neglecta）的粗提物显示出抗菌活性。使用肉汤微量稀释法对疏花糙苏的Et(2)O提取物进行生物活性导向分级分离，得到了三种新的锯齿烷型二萜类化合物，即2,19 - 二乙酰氧基 - 8 - 羟基锯齿 - 14 - 烯（2）、8,19 - 二羟基锯齿 - 14 - 烯（3）和8 - 羟基锯齿 - 14 - 烯 - 19 - 酸（4），以及一种已知的邻萘醌，通常称为双花萘醌（5）。通过一维和二维核磁共振、傅里叶变换红外光谱和高分辨率质谱确定了2 - 5的结构。化合物3 - 5对包括金黄色葡萄球菌、化脓性链球菌和肺炎链球菌在内的革兰氏阳性菌显示出抗菌活性。最低抑菌浓度（MIC）和最低杀菌浓度（MBC）分别为6.5至101.6微摩尔和12.7至202.9微摩尔。未观察到这些化合物对革兰氏阴性菌有活性。
