Antimycobacterial Activity of (<i>E</i>)-Phytol and Derivatives: A Preliminary Structure-Activity Study
作者:Mohamed Rajab、Charles Cantrell、Scott Franzblau、Nikolaus Fischer
DOI:10.1055/s-2006-957354
日期:1998.2
The crude methanol extract of the Kenyan shrub Leucas volkensii Gürke (Labiatae) displayed in a radiorespirometric bioassay antimycobacterial activity against Mycobacterium tuberculosis. Bioassay-guided fractionation of the crude extract led to the identification of (E)-phytol as the principal active component with a minimum inhibitory concentration (MIC) of 2 µg/ml, a value also observed for (3R,S,7/R,11R)-phytanol, (Z)-phytol, and a commercially available 2:1 mixture of (E)- and (Z)-phytol. The derivatives (E)-phytol acetate, a mixture of the (2S, 3S)- and (2R,3R)-isomers of (E)-phytol epoxide and (3R,S,7R,11R)-phytanic acid displayed lower activities with MICs of 8, 16, and >128 µg/ml, respectively. Geraniol and farnesol, displayed MICs of 64 and 8 µg/ml, respectively. The activities of (E)-phytol, (Z)-phytol and (3R,S,7R,11R)-phytanol were found to be in the same range as ethambutol, a clinically useful drug with an MIC in the range 0.95-3.8 µg/ml.
肯尼亚灌木 Leucas volkensii Gürke(唇形科植物)的甲醇粗提取物在放射性呼吸生物测定中显示出对结核分枝杆菌的抗霉菌活性。生物测定指导下对粗萃取物进行分馏,确定了(E)-斑蝥酚为主要活性成分,其最低抑菌浓度(MIC)为 2 µg/ml,(3R,S,7/R,11R)-斑蝥酚、(Z)-斑蝥酚以及市售的(E)-斑蝥酚和(Z)-斑蝥酚 2:1 混合物也具有相同的抑菌浓度。衍生物(E)-phytol acetate、(E)-phytol epoxide 的(2S, 3S)-和(2R,3R)-异构体的混合物以及(3R,S,7R,11R)-phytanic acid 的活性较低,其 MIC 值分别为 8、16 和 >128 µg/ml。香叶醇和法呢醇的 MIC 值分别为 64 微克/毫升和 8 微克/毫升。研究发现,(E)-斑鸠醇、(Z)-斑鸠醇和(3R,S,7R,11R)-斑鸠醇的活性与乙胺丁醇处于相同的范围,乙胺丁醇是一种临床常用药物,其 MIC 为 0.95-3.8 µg/ml。