Research Article
Chavan Rajashree and More Hari
Abstract
Non steroidal anti-inflammatory agents continue to be one of the most widely used groups of therapeutic agents. They are used for the treatment of inflammation including pain releasing, antipyretic and rheumatoid arthritis. However, almost all the NSAIDs under clinical usage are highly acidic in nature and suffer from a common drawback of gastrointestinal toxicity.The paper reports the synthesis and pharmacological screening of various derivatives of 1-(4, 5-dihydropyrazolyl)-indoles viz 1-(1-phenyl-5-substitutedphenyl-4,5-dihydro-1H-pyrazol-3-yl)-2- substitutedphenyl-1H-indole (4a-4l). These compounds (4a-4l) were synthesized by cyclization of chalcones of indole viz (E)-3-substitutedphenyl-1-(2-substitutedphenyl-1H-indol-1-yl) prop-2-en-1-one with phenyl hydrazine in presence of base NaOH. The structures of these synthesized compounds were supported by FT IR, 1H NMR and elemental analysis. These compounds were tested in vivo for their analgesic, anti-inflammatory and ulcerogenic activities. All these compounds tested (4a-4l) showed good analgesic and anti-inflammatory activities. Six compounds (4c, 4g, 4i, 4j, 4k, 4l) out of twelve compounds showed anti-inflammatory and analgesic activity comparable to the standard drug indomethacin with very less ulcerogenic action. The compounds 2-(4- chlorophenyl)-1-(5-(4-methoxyphenyl)-1-phenyl-4,5-dihydro-1H-pyrazol-3-yl)-1H-indole (4g) and 4-(3-(2-(4- methoxyphenyl)-1H-indol-1-yl)-1-phenyl-4,5-dihydro-1H-pyrazol-5-yl)-N,N-dimethylaniline (4l) showed good anti inflammatory as well as analgesic activity with less ulcerations. Pyrazolines having methoxy and dimethylamino group substituted at para position of phenyl ring at position-5 found to be more active than others, indicating that the presence of these functional groups may be helpful in more efficient binding with the receptors. The presence of methoxy group at para position of 2-phenyl ring on indole nucleus seems to be important for good anti inflammatory action.