Design, Synthesis And Antibacterial Activity Of Vanillyl Amine/Alcohol Derivatives

Capsaicinoids are stable components of chili peppers which have a wide range of biological activities against bacteria and yeasts. Capsiate was isolated from sweet pepper in Japan which also have biological activities similar to capsaicinoids.In this thesis the core structure of capsaicin compounds, vanillyl amine/alcohol, was combined with nitro furan/nitrothiophene by amidation or esterification reaction., forming a series of new structures in order to ameliorate the properties and improve the antibacterial activities.Twenty-six novel 26 Vanillyl amide (alcohol) derivatives were designed and synthesized, all the structures were characterized by 1H NMR,13C NMR, MS spectroscopy, and these derivatives were very easy to be prepared.The biological activities of all the compounds for gram-positive bacteria and gram-negative bacteria were assayed, and the structure-activity relationship was initially investigated. Compound A-1, A-2, A-6, A-7 and A-10 showed some level of antibacterial activities, and MIC values of A-7 on five resistant Staphylococcus aureus, NRS-1, NRS-70, NRS-100, NRS-108, NRS-271, were 0.31-0.63,1.25-1.56, 0.31-0.63,0.63-1.25,0.63-1.25 (μg/ml), respectively, which is better than that of the positive control drug vancomycin and tetracycline. Compound B-2 exhibited significant antibacterial activity (MIC= 0.3-0.78μg/ml) against Gram-positive bacteria. The vanillyl amine/vanillyl alcohol derivatives may be used for the preparation of or as the lead compounds of antibacterial drugs.