Synthesis of Schiff bases of naphtha[1,2-d]thiazol-2-amine and metal complexes of 2-(2'-hydroxy)benzylideneaminonaphthothiazole as potential antimicrobial agents.
OBJECTIVE
A series of 2-benzylideneaminonaphthothiazoles were designed and synthesized incorporating the lipophilic naphthalene ring to render them more capable of penetrating various biomembranes.


METHODS
Schiff bases were synthesized by the reaction of naphtha[1,2-d]thiazol-2-amine with various substituted aromatic aldehydes. 2-(2'-Hydroxy)benzylideneaminonaphthothiazole was converted to its Co(II), Ni(II) and Cu(II) metal complexes upon treatment with metal salts in ethanol. All the compounds were evaluated for their antibacterial activities by paper disc diffusion method with Gram positive Staphylococcus aureus and Staphylococcus epidermidis and Gram negative Escherichia coli and Pseudomonas aeruginosa bacteria. The minimum inhibitory concentrations of all the Schiff bases and metal complexes were determined by agar streak dilution method.


RESULTS
All the compounds moderately inhibited the growth of Gram positive and Gram negative bacteria. In the present study among all Schiff bases 2-(2'-hydroxy)benzylideneaminonaphthothiazole showed maximum inhibitory activity and among metal complexes Cu(II) metal complex was found to be most potent.


CONCLUSIONS
The results obtained validate the hypothesis that Schiff bases having substitution with halogens, hydroxyl group and nitro group at phenyl ring are required for the antibacterial activity while methoxy group at different positions in the aromatic ring has minimal role in the inhibitory activity. The results also indicated that the metal complexes are better antibacterial agents as compared to the Schiff bases.
Azam
Faizul
F
Department of Pharmaceutical Sciences, Kurukshetra University, Kurukshetra, Haryana, India. faizulazam@gmail.com
Singh
Satendra
S
Khokhra
Sukhbir Lal
SL
Prakash
Om
O
D000588:Amines / Q000138:chemical synthesis / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D003035:Cobalt; D003300:Copper; D009532:Nickel; D012545:Schiff Bases; D013329:Structure-Activity Relationship; D013844:Thiazoles / Q000138:chemical synthesis / Q000494:pharmacology
D000588:Amines; D000900:Anti-Bacterial Agents; D012545:Schiff Bases; D013844:Thiazoles; D003035:Cobalt; D003300:Copper; D009532:Nickel