| In recently years, according to the antibacterial mechanism and the latest achievements about bio-informatics of o-hydroxy diphenyl ether antimicrobials and zoles, we found that among o-hydroxy diphenyl ether antimicrobials, the molecular segments of o-hydroxyphenyl which possessed good affinity towards pathogeny targets, e.g. FabI and InhA, were critical structures to the molecules; many zoles show strong affinity and speciality towards HIV-TR,lanosterol 14α-demethylase, therefore, according to the superpostion principle of reinforcement of biological activities,we want to rationally assemble the two key molecular segments"o-hydroxyphenyl"and"1,2,4-triazole,1,3,4-oxadiazole,1,3,4-thiadia-zole"together, a total of thirty six compounds which have been not reported in the literature of 3-alkylthio-5-o-hydroxyphenyl-4H-1,2,4-triazoles,2-alkylthio-5-o-hydroxyphenyl-1,3,4-oxadiazoles and 2-alkylthio-5-o-hydroxyphenyl-1,3,4-thiadiazoles were designed and synthesised,The inhibitory activities of all compounds were tested.Salicylic hydrazide were synthesized by methylsalicylate with hydrazinehydrate, then, reacted with carbon disulfide or ammonium thiocyanate and hydrochloride to obtain5-(2-hyd- roxyphenyl)-1,3,4-oxadiazole-2-thiones,5-(2-hydroxyphenyl)-1,3,4-thiadia-zole-2-thiones,5- (2-hydroxyphenyl)-4H-1,2,4-triazole-3-thiones,At last,under alkaline conditions, the target compounds3-alkylthio-5-o-hydroxyphenyl-4H-1,2,4-triazoles,2-alkylthio-5-o-hydroxyphenyl-1,3,4-oxa-diazoles and 2-thio-5-o-hydroxyphenyl-1,3,4-thiadiazoles were obtained by nucleophilic substitution reaction with the halogenated acetophenone, the fluorinated- (chloromethyl) benzene or iodomethane. Studies have shown that three types of compounds in electrophilic substitution reaction time were 5-(2-hydroxyphenyl)-1,3,4-thiadia-zole-2-thiones <5-(2-hydroxyphenyl)-4H-1,2,4-triazole-3-thiones<5-(2-hydroxyphenyl)-1,3,4-oxadiazole-2-thiones, which is due to atom electronegativity were S<N<O, leading to thiol on the electron density changes caused by. In addition, electrophilic reagent (thione) on the substituents on electrophilic substitution reactions have important implications for the use of chloroacetophenone electrophilic reagents, the benzene ring substituents on the reaction to the order of blunt:4-NH2>4-OCH3>2,4-CH3>4-CH3>4-Br>4-Cl;using benzyl chloride as the electrophilic reagent, the benzene ring on the substituent to the blunt response were H>4-F >2-F>3-F; use of bromide,iodide reagent for electrophilic reagents,helping improve the pro-eletrophilic substitution reaction.All compounds were characterized by 1H NMR,IR characterized to confirm.The result of preliminary bioassay showed that the three title compounds had a good antibacterial activities against Monilia albican and Escherichia coli at 0.01% mass concentration and a favorable extent of antibacterial activities against Staphylococcus aureus. especially, the compounds which acetophenone with Cl,Br had about 95～100% inhibitory rate against Monilia albican, Escherichia coli and Staphylococcus aureus. They will be a series of potential broadly antibacterial compounds.Antibacterial activity of three series of compounds were different from that zole ring structure changes can affect its biological activity.And the three series of compounds antibacterial activities against Monilia albican and Escherichia coli were oxadiazole>triazole >thiadiazole;but against Staphylococcus aureus the resrults was thiadiazole>triazole> oxadiazole.Target molecules, the fragments of the bridge connecting the two aromatic compounds to the anti-bacterial activity has an important impact, the compounds with the bridge of-SCH2CO- of antibacterial activity generally higher than the compounds with bridge of-SCH2-, Noting the introduction of carbonyl compounds can improve the antibacterial activity. Benzene ring substituents on the antibacterial activity of the compounds have important impact, the antibacterial activities of title compounds were enhanced by the halogen groups ,such as Cl,Br. |
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