Synthesis of some piperazinobenzoxazole derivatives and their antimicrobial properties

240-247<span style="font-size:11.0pt;mso-bidi-font-size: 10.0pt;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:"times="" roman";letter-spacing:-.2pt;mso-ansi-language:="" en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="" lang="EN-US">A series of 2-(p-substitutedphenyl/benzyl)-5-[3-[4-[(p-chlorophenyl)/phenyl]piperazin-1-yl]propionamido]-benzoxazoles (<b style="mso-bidi-font-weight: normal">3-22) have been synthesized towards discovering new antimicrobial compounds in order to fight against pathogens, which have become resistant to antibiotics and are the cause of increased mortality and morbidity throughout the world. Structures of new derivatives have been elucidated by spectral techniques. New and previously synthesized benzoxazoles have been evaluated for their antibacterial and antifungal activity against standard strains, and their drug-resistant isolates in comparison with reference drugs. This study is aimed to investigate the efficacy of the antimicrobial effect of different amido bridges on the same homologue structures of benzoxazole compounds. Compounds 3-22 exhibit broad antibacterial activity with MIC (Minimum Inhibitory Concentration) values of 128-256 µg/mL against Staphylococcus aureus and its isolate except for derivative <b style="mso-bidi-font-weight: normal">7 that has a MIC value of 32 µg/mL against S. aureus isolate and compounds 3 and <b style="mso-bidi-font-weight: normal">22 which have <span style="font-size:11.0pt; mso-bidi-font-size:9.0pt;font-family:" times="" new="" roman";mso-fareast-font-family:="" "times="" roman";mso-bidi-font-family:"times="" roman";mso-ansi-language:="" en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="" lang="EN-US">MIC value of 512 µg/mL against S. aureus. Also, t<span style="font-size:9.0pt; font-family:" times="" new="" roman";mso-fareast-font-family:"arial="" unicode="" ms";="" mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;font-weight:="" normal"="" lang="EN-US">he tested compounds 3-22 possess low antifungal activity with MIC values of 128 µg/mL against Candida albicans in comparison with antifungal reference drugs, fluconazole and amphotericin B.</span

Studıes on the synthesıs of 3-methyl-6-(substıtuted-urea/-thıourea)-2(3<i style="mso-bidi-font-style:normal">H</i>)-benzothıazolone derıvatıves and antımıcrobıal actıvıtıes

253-259A series of sixteen new urea and thiourea derivatives at position 6 of 3-methyl-2(3H)-benzothiazolone ring have been prepared and studied using IR, 1H NMR, mass spectra and elemental analysis. The urea and thiourea derivatives have been obtained by the reaction of 6-amino-3-methyl-2(3H)-benzothiazolone with appropriate isocyanates and isothiocyanates. The antibacterial, antifungal and antimycobacterial activities of the synthesized compounds have been evaluated in vitro using microdilution and microplate methods

Synthesis and different biological activities of novel benzoxazoles

A series of 2-[4-(4-substitutedbenzamido/phenylacetamido/butanamido)phenyl]-5-ethylsulphonyl-benzoxazole derivatives were synthesized and biologically evaluated as possible antimicrobial agents and inhibitors of tyrosinase, acetylcholinesterase (AChE), and butyrylcholinesterase (BChE). The results demonstrated that the synthesized compounds exhibited a broad spectrum of activity with minimum inhibitory concentration (MIC) values of 128-16 μg/ml against some Gram-positive, Gram-negative bacteria as well as Candida albicans and C. krusei. The compound 10 displayed higher activity in this series against methicilline resistant Staphylococcus aureus (MRSA) with a MIC value of 16 μg/ml than the compared control drugs ampicillin and ceftriaxone. Compound 14 showed moderate tyrosinase inhibition, however, none of the compounds showed effect as inhibitor of AChE and BChE