Synthesis Of New Indole Derivatives Structurally Related To Camalexin And Biological Evaluation Of Antibacterial Activity
a series of novel imidazole derivatives with indole moiety was designed by using camalexin as a molecular scaffold. Seven compounds with different length of the carboxylic acid ethyl esters chain structure were prepared. The anti-microbial activity of synthesized compounds against E. coli and S. aureus were determined by using agar cup plate assayand the minimal inhibition concentration (MIC) of all the test compounds were determined in a liquid culture method. We found that compounds synthesized in the present work did not exhibit anti-microbial activity against E. coli. However, all the synthesized compounds displayed anti-microbial activity against S. aureus. The diameter of inhibition circle of the compound 3b (1 mg/disk) was found approximately 15�1.5 mm while ampicillin (10 g/disk) was found approximately 34�0.6 mm. compounds 3c, 3d and 3e displayed does-dependent effect on anti-microbial activity against S. aureus. Among the synthesized compounds, compound 3g displayed the most potent anti-microbial activity against S. aureus with a MIC value approximately 8g/ml. Our results clearly indicated that the length of the carboxylic acid ethyl ester chain greatly influence the anti-microbial activity of this synthetic series against S. aureus.
Index Terms- barassinosteriod, brassinosteroid biosynthesis inhibitors, Yucaizol, plant hormone.