Shahverdi Ahmad Reza, Fakhimi Ali, Zarrini Gholamreza, Dehghan Gholamreza, Iranshahi Mehrdad
Department of Pharmaceutical Biotechnology and Medicinal Plant Research Center, Faculty of Pharmacy, Medical Sciences/University of Tehran, Tehran 1417614411, Iran.
Biol Pharm Bull. 2007 Sep;30(9):1805-7. doi: 10.1248/bpb.30.1805.
In this study the enhancement effect of Ferula szowitsiana roots' acetone extract on the antibacterial activity of penicillin G and cephalexin was evaluated against Staphylococcus aureus. Disk diffusion and broth dilution methods were used to determine the antibacterial activity of these antibiotics in the absence and presence of plant extract and its various fractions separated by TLC plate. The active component of plant extract involved in enhancement of penicillin G's and cephalexin's activities had Rf=0.336 on a TLC plate. The spectral data ((1)H-, (13)C-NMR) of this compound revealed that this compound was 7-[6-(beta-carboxyethyl)-5-isopropylidene-1,2-dimethylcyclo-hexylmethoxy]coumarin (galbanic acid), previously isolated from Ferula assa-foetida. In the presence of sub-inhibitory concentration of galbanic acid (100 microg/ml) the MIC of penicillin G for S. aureus decreased from 64 to 1 (a sixteen four-fold decrease) and for cephalexin from 128 to 1 microg/ml (a one hundred twenty eight-fold decrease). The highest fold decrease in MIC was observed for cephalexin in combination of galbanic acid against test strain. These results signify that the low concentration of galbanic acid (100 microg/ml) potentiates the antimicrobial action of penicillin G and cephalexin suggesting a possible utilization of these compounds in combination therapy against S. aureus.
本研究评估了新疆阿魏根丙酮提取物对青霉素G和头孢氨苄抗金黄色葡萄球菌抗菌活性的增强作用。采用纸片扩散法和肉汤稀释法，分别测定了在不存在和存在植物提取物及其通过薄层层析板分离得到的不同组分的情况下，这些抗生素的抗菌活性。植物提取物中参与增强青霉素G和头孢氨苄活性的活性成分在薄层层析板上的比移值（Rf）为0.336。该化合物的光谱数据（氢谱、碳谱）表明，此化合物为7-[6-(β-羧乙基)-5-异亚丙基-1,2-二甲基环己基甲氧基]香豆素（伽本酸），先前已从阿魏中分离得到。在存在亚抑制浓度的伽本酸（100微克/毫升）时，青霉素G对金黄色葡萄球菌的最低抑菌浓度（MIC）从64降至1微克/毫升（降低了64倍），头孢氨苄的MIC从128降至1微克/毫升（降低了128倍）。在伽本酸与测试菌株的组合中，头孢氨苄的MIC下降倍数最高。这些结果表明，低浓度的伽本酸（100微克/毫升）可增强青霉素G和头孢氨苄的抗菌作用，提示这些化合物在联合治疗金黄色葡萄球菌感染方面可能具有应用价值。
