Synthesis, antimicrobial activity and QSARs of new benzoxazine-3-ones.

New ethyl 3,4-dihydro-3-oxo-4,6,7-trisubstituted-2H-1,4-benzoxazine-2-acetate derivatives were synthesized and their structures were elucidated by IR, (1)H NMR and mass spectral data. Antimicrobial activity of the compounds was investigated by using the method of twofold serial dilution technique against different Gram-positive, Gram-negative bacteria and some Candida species in comparison to standard drugs. Microbiological results indicated that the synthesized compounds possessed a broad spectrum of activity having MIC values of 6.25-100 micro g/ml against the tested microorganisms. The QSAR analysis of a set of these compounds tested for growth inhibitory activity against Candida krusei was performed by using the computer-assisted multiple regression procedure. The activity contributions for substituent effects of these compounds were determined from the correlation equation for predictions of the lead optimization.

Synthesis and antimicrobial activity of some new 2-phenyl-N-substituted carboxamido-1H-benzimidazole derivatives.

Some 1H-benzimidazole-carboxamide derivatives were prepared and their antimicrobial activities against Staphyloccus aureus, Escherichia coli and Candida albicans evaluated. Compounds 18, 22, and 25 exhibited the best activity against Candida albicans.

Synthesis and antimicrobial activities of 5-fluoro-1,2,6-trisubstituted benzimidazole carboxamide and acetamide derivatives.

Some 5-fluoro-6-substitute-1 H-benzimidazole-2-carbamates (12a-e), 5-fluoro-6-substituted 1H-benzimidazole-2-acetate (13a-e) and 2-acetamide (14a-f) derivatives, 2-acetamido-5-fluoro-6-(morpholin-4-yl)-1-propyl-1H-benzimidazole (15), and 1-cyclopropyl-2-ethyl-5-fluoro-6-(4-methylpiperazin-1-yl)- 1H-benzimidazole (16) were synthesized, and their antimicrobial and antifungal activities evaluated. Compound 12c exhibited the best activity against Candida albicans.

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

The synthesis and microbiological activity of a new series of 5-benzamido- and 5-phenylacetamidosubstituted-2-phenylbenzoxazole derivatives (1-26) were described. The in vitro microbiological activity of the compounds was determined against Gram-positive, Gram-negative bacteria and the yeast Candida albicans in comparison with standard drugs. Microbiological results indicated that the synthesized compounds possessed a broad spectrum of activity against the tested microorganisms. The compounds 1, 21, 25 showed higher activity than tetracycline and streptomycin against Pseudomonas aeruginosa.

Synthesis of 3-substituted phenacyl-5-[2-phenyl-4H-4-oxo-1-benzopyran-6- yl)methylenyl]-thiazolidine-2,4-diones and evaluation of their antimicrobial activity.

Synthesis and physico-chemical properties of two 3-substituted phenacyl-thiazolidine-2,4-diones (2c-d) and four 3-substituted phenacyl-5-[2-phenyl-4H-4-oxo-1-benzopyran-6-yl)methyl-enyl]-thiazolidin e- 2,4-diones (4a-d) are described. These products were synthesized by Knoevenagel reaction from flavone-6-carboxaldehyde (3) and 3-(substituted phenacyl)- thiazolidine-2,4-diones (2a-d). Antibacterial and antifungal activities were investigated for these compounds.

Synthesis and microbiological activity of some N-(o-hydroxyphenyl)benzamides and phenylacetamides as the possible metabolites of antimicrobial active benzoxazoles: part II.

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 microg/ml against the Gram-negative microorganism Klebsiella pneumoniae. Most of the compounds exhibited antibacterial activity at an MIC value of 25 microg/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 microg/ml). The antimicrobial activity of some of these benzamide and phenylacetamide derivatives (2a, 2b, 2f, 2g, 2h and 2k), 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 antimicrobial activity of some new 4-hydroxy-2H- 1,4-benzoxazin-3(4H)-ones.

Some 4-hydroxy-2H-1,4-benzoxazin-3(4H)-ones were synthesized and evaluated for their antimicrobial activities against Staphylococcus aureus, Escherichia coli and Candida albicans. Compounds 9, and 10 exhibited the best activity against Candida albicans.

Synthesis and antimicrobial activity of some new flavonyl oxime ether derivatives.

The synthesis of a series of 6 compounds related to 2-(4'-formyl-phenyl)-4]H-1-benzopyran-4-one O-substituted oxime and the results of a study of their biological activity are reported. The structural assignments of the compounds is based upon various spectral data. The prepared compounds were screened for their in vitro antibacterial and antifungal activities. Compound F3 exhibited the best antifungal activity compared with ketoconazole and fluconazole.

Synthesis and antimicrobial activity of some new benzimidazole carboxylates and carboxamides.

Some benzimidazole carboxylates and carboxamides were synthesized and evaluated for their antimicrobial activities against Staphylococcus aureus, Escherichia coli and Candida albicans. Among the investigated compounds 2d exhibited best activity against C. albicans.

Synthesis and antimicrobial evaluation of some 3-(substituted phenacyl)-5-[4'-(4H-4-oxo-1-benzopyran-2-yl)-benzylidene]-2,4- thiazolidinediones.

Synthesis and in vitro antimicrobial activity of some 3-(substituted phenacyl)-5-[4'(4H-4-oxo-1-benzopyran-2-yl)-benzylidene]-2-4- thiazolidinedione derivatives are described. These products were synthesized by the Knoevenagel reaction from 4'-flavone carboxaldehyde and 3-substituted phenacyl-2,4-thiazolidinediones.

Synthesis and antimicrobial activity of some novel 2,5- and/or 6-substituted benzoxazole and benzimidazole derivatives.

A new series of 2,5- and/or 6-substituted benzoxazoles (7a-f), benzimidazoles (8a-g) holding cyclohexyl or cyclopentyl moieties at position 2 and 5- or 6-substituted-2-cyclohexylaminomethylbenzoxazoles (9a, b) was synthesized in order to determine their antimicrobial activities and feasible structure-activity relationships. The synthesized compounds were tested in vitro against three Gram-positive, two Gram-negative bacteria and the yeast Candida albicans in comparison with several control drugs. Microbiological results showed that the synthesized compounds were possessing a broad spectrum of antibacterial activity against the tested microorganisms. 5-Chloro-2-(2-cyclohexylethyl)benzimidazole (8g) was found as the most active compound against the screened Gram-positive bacteria strains at a minimum inhibitory concentration (MIC) value of 12.5 microg/ml. However, it exhibited lower antibacterial potency than the compared control drugs. On the other side, compounds 7-9 indicated significant antibacterial activity against the Gram-negative enterobacter Pseudomonas aeruginosa having MIC values of 50 microg/ml, providing either the same effect as tetracycline or higher activity than streptomycin, but showing less potency than the compared control drug gentamycin. Moreover, the synthesized compounds also possessed antimycotic activity against the yeast C. albicans showing MIC values between 25-50 microg/ml.

Synthesis of some new benzimidazolecarboxamides and evaluation of their antimicrobial activity.

A series of 1,2-disubstituted benzimidazole-5(6)-carboxamides was prepared and evaluated in vitro for antimicrobial activity against Staphyloccus aureus, Escherichia coli and Candida albicans. The precursor benzimidazolecarboxylic acids 4a-c and 9a-c were prepared via oxidative condensation of diaminobenzoic acids with aldehydes and via several steps over the 2(1H)-benzimidazolones, respectively. All acids were converted to their acyl chlorides with SOCl2, then amidified with several N,N'-dialkylaminoethyl derivatives. Compounds 8a-c, 20 and 22 exhibited the best activity.

Synthesis and antimicrobial activity of some new anilino benzimidazoles.

A series of 2-(anilino or 2,6-dichloroanilino)-1,5(6)-disubstituted-1H-benzimidazoles (1-13) were prepared by reaction of several 2-chloro- or 2-chloromethyl-1H-benzimidazoles with aniline derivatives. The prepared compounds were screened for their in vitro antibacterial and antifungal activities. Compounds 2, 8, and 9 exhibited the best activity.

Synthesis and microbiological activity of some novel N-(2-hydroxyl-5-substitutedphenyl)benzacetamides, phenoxyacetamides and thiophenoxyacetamides as the possible metabolites of antimicrobial active benzoxazoles.

Synthesis of some novel N-(2-hydroxyl-5-substitutedphenyl)benzacetamides, phenoxyacetamides and thiophenoxyacetamides (5a-k) were described in order to determine their in vitro antimicrobial activity against 3 Gram-positive, 3 Gram-negative bacteria and the fungus Candida albicans comparing with several control drugs. The derivative 5e was found active at a MIC value of 25 micrograms/ml against the whole tested Gram-positive bacteria strains and the Gram-negative microorganism Klebsiella pneumoniae. Moreover, the synthesized compounds 5a-k exhibited significant antibacterial activity against the enterobacter Pseudomonas aureginosae when compared to the control drugs. For the antifungal avtivity against C. albicans, the compound 5k was found more active than the other synthesized derivatives. On the other hand, the antimicrobial activity of some of these acetamide derivatives (5c, 5d, 5e, 5j and 5k) which are the possible metabolites of benzoxazoles, were also compared with their cyclic analogues 6-10. However, most of the MIC values of the benzoxazole derivatives provided better activity than the compared acetamides, while some others of the acetamide derivatives possessed either one fold improved (5d, 5e and 5j) or the same potency (5c, 5d, 5e, 5j and 5k) against the tested microorganisms.

Synthesis and antimicrobial activity of some new piperidinyl benzimidazoles.

A series of 2-(4-methylpiperidin-1-yl)-1,5(6)-disubstituted-1H-benzimidazoles (1-18) were prepared through the reaction of 2-chloro (or 2-chloromethyl)-1H-benzimidazole derivatives with 4-methylpiperidine. For the preparation of the individual isomers, compounds 7, 9 and 18 were synthesized by a multistep procedure. The prepared compounds were screened for their in vitro antibacterial and antifungal activities. Compound 3 and 4 exhibited the best antifungal activity.

[Microbiological quality control of lipsticks which are on the market in our country]. / Yurdumuzda uretilen ve kullanilan dudak boyalarinin mikrobiyolojik karlite kontrolleri üzerinde arastirmalar.

In this study, microbiological quality control of lipsticks has been investigated. In 81 samples, we found that 34 of them (42%) had total aerobic plate count and 19 of them (23.5%) were found to consist mold and yeast which are not allowed by the cosmetic regulations. In none of the samples, pathogen microorganisms such as S. aureus, P. aeruginosa, E.coli, Salmonella and Shigella were detected. Indeed, after carefully examining of the microbiological content of these lipsticks, their biostatistical efficiency was also determined. In each counting procedure, for different bacteria, it was found that only one sample was effective at the 3rd and 14th day. The remaining 9 lipstick samples (90%) were kept under investigation until the end of the testing procedure on the 28th day.