Synthesis and microbiological activity of some 2H-1,4-Benzothiazin-3-one derivatives (original) (raw)

Synthesis and microbiological activity of some novel 5-or 6-methyl-2-(2, 4-disubstituted phenyl) benzoxazole derivatives

Il Farmaco, 1998

The synthesis of some N-(o-hydroxyphenyl)benzamides and benzacetamides (2a-2p) in order to determine their in vitro antimicrobial activity against two Gram-positive bacteria, three Gram-negative bacteria and the fungus Candida albicans is described. The new compounds were compared with several control drugs. The derivative 2g, 4-amino-N-(o-hydroxyphenyl)benzamide, was found active at an MIC value of 25 mg/ml against the Gram-negative microorganism Klebsiella pneumoniae. Most of the compounds exhibited antibacterial activity at an MIC value of 25 mg/ml against Pseudomonas aureginosa. For the antifungal activity against C. albicans, compounds 2e, 2h and 2m were found more active than the other derivatives (MIC 12.5 mg/ml). The antimicrobial activity of some of these benzamide and phenylacetamide derivatives , possible metabolites of benzoxazoles, was also compared with that of the cyclic analogues 3-8. Compound 2f possesses two dilutions better antifungal activity than its cyclic analogue the benzoxazole derivative 5 against C. albicans, while having one dilution better antibacterial activity against Streptococcus faecalis and K. pneumoniae.

Synthesis and microbiological activity of some novel 5-benzamido- and 5-phenylacetamido- substituted 2-phenylbenzoxazole derivatives

Il Farmaco, 2000

The synthesis of some N-(o-hydroxyphenyl)benzamides and benzacetamides (2a-2p) in order to determine their in vitro antimicrobial activity against two Gram-positive bacteria, three Gram-negative bacteria and the fungus Candida albicans is described. The new compounds were compared with several control drugs. The derivative 2g, 4-amino-N-(o-hydroxyphenyl)benzamide, was found active at an MIC value of 25 mg/ml against the Gram-negative microorganism Klebsiella pneumoniae. Most of the compounds exhibited antibacterial activity at an MIC value of 25 mg/ml against Pseudomonas aureginosa. For the antifungal activity against C. albicans, compounds 2e, 2h and 2m were found more active than the other derivatives (MIC 12.5 mg/ml). The antimicrobial activity of some of these benzamide and phenylacetamide derivatives , possible metabolites of benzoxazoles, was also compared with that of the cyclic analogues 3-8. Compound 2f possesses two dilutions better antifungal activity than its cyclic analogue the benzoxazole derivative 5 against C. albicans, while having one dilution better antibacterial activity against Streptococcus faecalis and K. pneumoniae.

Synthesis and microbiological activity of some N-(2-hydroxy-4-substitutedphenyl)benzamides, phenylacetamides and furamides as the possible metabolites of antimicrobial active benzoxazoles

Farmaco, 2002

The synthesis of some N-(o-hydroxyphenyl)benzamides and benzacetamides (2a-2p) in order to determine their in vitro antimicrobial activity against two Gram-positive bacteria, three Gram-negative bacteria and the fungus Candida albicans is described. The new compounds were compared with several control drugs. The derivative 2g, 4-amino-N-(o-hydroxyphenyl)benzamide, was found active at an MIC value of 25 mg/ml against the Gram-negative microorganism Klebsiella pneumoniae. Most of the compounds exhibited antibacterial activity at an MIC value of 25 mg/ml against Pseudomonas aureginosa. For the antifungal activity against C. albicans, compounds 2e, 2h and 2m were found more active than the other derivatives (MIC 12.5 mg/ml). The antimicrobial activity of some of these benzamide and phenylacetamide derivatives , possible metabolites of benzoxazoles, was also compared with that of the cyclic analogues 3-8. Compound 2f possesses two dilutions better antifungal activity than its cyclic analogue the benzoxazole derivative 5 against C. albicans, while having one dilution better antibacterial activity against Streptococcus faecalis and K. pneumoniae.

Synthesis and Microbiological Activity of Some Novel N-[2-(p-Substitutedphenyl)-5-benzoxazolyl]-cyclohexyl Carboxamide, -cyclohexyl Acetamide and -cyclohexyl Propionamide Derivatives

Cheminform, 2003

The synthesis of some N-(o-hydroxyphenyl)benzamides and benzacetamides (2a-2p) in order to determine their in vitro antimicrobial activity against two Gram-positive bacteria, three Gram-negative bacteria and the fungus Candida albicans is described. The new compounds were compared with several control drugs. The derivative 2g, 4-amino-N-(o-hydroxyphenyl)benzamide, was found active at an MIC value of 25 mg/ml against the Gram-negative microorganism Klebsiella pneumoniae. Most of the compounds exhibited antibacterial activity at an MIC value of 25 mg/ml against Pseudomonas aureginosa. For the antifungal activity against C. albicans, compounds 2e, 2h and 2m were found more active than the other derivatives (MIC 12.5 mg/ml). The antimicrobial activity of some of these benzamide and phenylacetamide derivatives , possible metabolites of benzoxazoles, was also compared with that of the cyclic analogues 3-8. Compound 2f possesses two dilutions better antifungal activity than its cyclic analogue the benzoxazole derivative 5 against C. albicans, while having one dilution better antibacterial activity against Streptococcus faecalis and K. pneumoniae.

Synthesis and biological activity of some new benzoxazoles

European Journal of Medicinal Chemistry, 2008

The synthesis and antimicrobial activity of a new series of 5-ethylsulphonyl-2-(substituted-phenyl/substituted-benzyl and/or phenylethyl)benzoxazole derivatives (3a–3t) except 3a, 3g, 3h, 3k [R.S. Pottorf, N.K. Chadha, M. Katkevies, V. Ozola, E. Suna, H. Ghane, T. Regberg, M.R. Player, Tetrahedron Lett. 44 (1) (2003) 175] were described. The in vitro antimicrobial activity of the compounds was determined against some Gram-positive, Gram-negative bacteria, a fungi Candida albicans and their drug-resistant isolates in comparison with standard drugs. Antimicrobial results indicated that the synthesized compounds possessed a broad spectrum of activity with MIC values 250–7.81 μg/ml. While all compounds are less potent than fluconazole against C. albicans, most of them are more potent than fluconazole against C. albicans isolate.

SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL EVALUATION OF SOME NEW BENZOTHIAZOLE DERIVATIVES Original Article

International Journal of Pharmacy and Pharmaceutical Sciences, 2015

Objective: Synthesis, characterization and antimicrobial evaluation of some new 1,3-benzothiazolyl pyrazole derivatives. Methods: Aseries of novel2-[3-(substituted phenyl)-4-formylpyrazol-1-yl]-6-chloro benzothiazole derivatives (5a-g) have been synthesized by cyclization through Vilsmeier-Haack reaction on hydrazones (4a-g)of substituted aromatic ketones with 6-chloro benzothiazol-2-yl hydrazine under microwave irradiation in fairly good yields. All the newly synthesized compounds were characterized by IR, 1 Results: The results revealed that all 1,3-benzothiazole pyrazole derivatives(5a-g) were synthesized in satisfactory yields and pharmacologically evaluated for their in vitro antimicrobial activity. All the synthesized compounds were in good agreement with elemental and spectral data. Some of the tested compounds showed good to moderate antimicrobial activity against all tested pathogenic bacterial and fungal strains. HNMR, Mass spectral studies and elemental analysis and were screened for their in vitro antibacterial and antifungal activities also. Conclusion: For the present investigation we have prepared benzothiazole derivatives that are incorporated with pyrazolyl moiety with the hope of potentiating the activity of two such units in the same compound. Compounds 5b, 5c, and 5a showed excellent antibacterial and antifungal activities as compared to reference drugs norfloxacin and ketoconazole.

Synthesis, antimicrobial activity, pharmacophore analysis of some new 2-(substitutedphenyl/benzyl)-5-[(2-benzofuryl)carboxamido]benzoxazoles

European Journal of Medicinal Chemistry, 2008

The synthesis and antimicrobial activity of a new series of 2-(substitutedphenyl/benzyl)-5-[(2-benzofuryl)carboxamido]benzoxazole derivatives 3–12 were described. The in vitro antimicrobial activity of the compounds was determined against some Gram-positive, Gram-negative bacteria and fungi and their drug-resistant isolates in comparison with standard drugs. Antimicrobial results indicated that the synthesized compounds possessed a broad spectrum of activity with MIC values 500–15.625 μg/ml. In the series, the most active compound against Candida krusei and Candida albicans isolate is 8 with MIC value 31.25 μg/ml. However, it is one dilution less potent than the compared fluconazole. Some of the screened compounds exhibit significant activity, having MIC value as 31.25 μg/ml in Pseudomonas aeruginosa having same activity as Rifampicin. Furthermore, considering the worth of developing new antibacterial agents against drug-resistant P. aeruginosa the present study explores the structure–activity relationship analysis of 2-(substitutedphenyl/benzyl)-5-[(2-benzofuryl)carboxamido]benzoxazoles using 3D-common features pharmacophore hypotheses approach.New 2-(substitutedphenyl/benzyl)-5-[(2-benzofuryl)carboxamido]benzoxazole derivatives were synthesized and antimicrobial activity of the compounds was investigated. The in vitro antimicrobial activity of the compounds was determined against some Gram-positive, Gram-negative bacteria and Candida albicans, Candida krusei and their drug-resistant isolates in comparison with standard drugs. Antimicrobial results indicated that the synthesized compounds possessed a broad spectrum of activity with MIC values 500–15.125 μg/ml. In the series, the most active compound against C. krusei and C. albicans isolates is 8 with MIC value 31.25 μg/ml. However, it is one dilution less potent than the compared fluconazole. Some of the screened compounds exhibit significant activity, having MIC value as 31.25 μg/ml in Pseudomonas aeruginosa having same activity as Rifampicin. Furthermore, considering the worth of developing new antibacterial agents against drug-resistant P. aeruginosa the present study explores the structure–activity relationship analysis of 2-(substitutedphenyl/benzyl)-5-[(2-benzofuryl)carboxamido]benzoxazoles using 3D-common features pharmacophore hypotheses approach.

Synthesis and evaluation of some new benzothiazole derivatives as potential antimicrobial agents

European Journal of Medicinal Chemistry, 2010

As benzothiazole has proven to be good antimicrobial agent, a novel series of Schiff bases of benzothiazole derivatives were synthesized. Thus condensation of 5-[2-(1,3-benzothiazol-2-yl-amino) ethyl]-4-amino-3-mercapto-(4H)-1,2,4-triazole 5 with appropriate aromatic aldehydes afforded 5-[2-(1,3benzothiazol-2-yl-amino)ethyl]-4-(arylideneamino)-3-mercapto-(4H)-1,2,4-triazoles 6aeg. Structures of the synthesized compounds were elucidated on the basis of elemental analyses and spectral data. All the synthesized compounds were screened for their antimicrobial activity.