antibacterial activity

ABSTRACTThe substituted 4-(bromomethyl)-N-(4-ethyl-6-methylpyrimidin-2-yl) benzamide derivatives 6a-k has been synthesis from reaction in between substituted 4-ethyl-6-methylpyrimidin-2-amine and 4-(bromomethyl)benzoyl bromide 5 in presence of KOH. Type of aldol condensation reaction in between aldehydes and ketones to form ?,?-Unsaturated carbonyl compounds3 this compound has been reacted with guanidine in presence of dry alcohol to convert 4-ethyl-6-methylpyrimidin-2-amine4.Chemical structures of all the new compounds were established by IR, 1H, 13C NMR, MS and elemental data. The compounds 6a-k were evaluated for their antibacterial activity against Gram-positive bacteria viz.  Bacillus subtilis, Bacillus sphaericus and Staphylococcus aureus, and three Gram-negative bacteria viz. Pseudomonas aeruginosa, Klebsiella aerogenes and Chromobacterium violaceum  and also evaluate their antifungal activity against Candida albicans (C.albicans)(ATCC 10231), Aspergillus fumigates(A.fumigatus) (HIC 6094), Trichophyton rubrum(T. rubrum) (IFO 9185), and Trichophyton mentagrophytes(T. mentagrophytes) (IFO 40996) Amongst them, compounds containing [3-hydrophenyl] moiety 6d, [3-chlorophenyl] moiety 6f and [4-nitrophenyl] moiety 6h showed significant antibacterial and antifungal activity, almost equal/more than the activity of the standard drugs Streptomycin and Amphotericin-B. Further, the compounds 6a-k were also screened for Most of these new compounds showed appreciable activity against test bacteria and fungi and emerged as potential molecules for further development. Keywords: Synthesis,4-(bromomethyl)-N-(4-ethyl-6-methylpyrimidin-2-yl) Benzamide, antibacterial activity, antifungal activity.  

Benzimidazole derivatives play an important role in medicinal field with many biological and pharmacological activities related to it. Extensive biochemical and pharmacological studies have confirmed that the potency of these clinically useful drugs in treatment of microbial infections is encouraging and inspiring for further development of some more potent and significant compounds. A series of benzopyrone substituted benzimidazole derivatives were synthesized by reacting benzopyrone-3-carboxylic acid with o-phenylene diamine. The analogues were synthesized in a good yield. The structural characterizations for derivatives were carried out by IR, 1HNMR and Mass spectral studies. The compounds were subjected for antibacterial screening, among them 4c and 4i showed appreciable activity against all the strains. It can be concluded from the antibacterial study that the derivatives may be proved useful for future development.

As many scientific and technical observations are pouring informations about the activity and effectiveness of synthetic and semi synthetic derivatives related to quinolines and benzimidazoles it was concern to explore this two leads in a single molecular entity.  The present study embodied the synthesis and evaluation of antibacterial activity of a series of benzimidazole substituted quinoline derivatives condensed with different amines. The derivatives were synthesized in moderate to good yields. The characterizations for the synthesized derivatives were done by IR, 1H NMR and Mass spectral analysis. The compounds were then subjected for antibacterial screening, among them 4c and 4d showed appreciable activity against all the strains used. In the light of the results obtained from antibacterial studies, these derivatives can be further thoroughly investigated for future prospect.

Triazine backbone is present in a large number of bioactive substances and is known for their pharmacological activities like antimicrobial, antitumour and antiviral activity. Pyrazoles are another class of heterocyclic compounds associated with significant biological activities like anti-inflammatory, anticonvulsant and antimicrobial activity. In this view, it was proposed to synthesize some novel pyrazolo[3,4-e][1,2,4]triazines from 3,7-dimethyl pyrazolo[4,3-e] oxadiazine. In the current investigation, ethyl acetoacetate was condensed with hydrazine hydrate in ethanol to give 3-methylpyrazol-5-one. The pyrazole derivative was brominated by using bromine in acetic acid as brominating agent to give 4, 4- dibromo-3-methylpyrazol-5-one. This compound was then cyclized with acetic anhydride and hydrazine hydrate to get 3, 7-dimethyl pyrazolo[4,3-e]oxadiazine. This compound on further reaction with different substituted amines generates 4-(aryl/heteroaryl)-3,7-dimethyl-pyrazolo [3,4-e][1,2,4]triazines. The synthesized compounds were screened for their antibacterial and antifungal activity against S. aureus strain of Gram positive, E. coli the strain of Gram negative and A. niger strain of fungus by standard methods. The results suggest that the compounds 4a and 4c exhibited significant antifungal activity. Gentamycin, ciprofloxacin, cefotaxime and amphotericine B were used as standard drugs. The structures of the synthesized compounds were confirmed using analytical and spectral techniques (IR, 1H NMR and Mass spectral data).