Design and synthesis of pyridazinone-substituted benzenesulphonylurea derivatives as anti-hyperglycaemic agents and inhibitors of aldose reductase - an enzyme embroiled in diabetic complications.

Thirty new aryl-pyridazinone-substituted benzenesulphonylurea derivatives (I-XXX) were synthesized and evaluated for their anti-hyperglycaemic activity in glucose-fed hyperglycaemic normal rats. Twenty-three compounds (III-XI, XIV-XVII, XIX-XXIV, XXVI and XXVIII-XXX) showed more or comparable area under the curve (AUC) reduction percentage (ranging from 21.9% to 35.5%) as compared to the standard drug gliclazide (22.0%). On the basis of docking results, 18 compounds were screened for their in vitro ability to inhibit rat lens aldose reductase. Ten compounds (III-VI, XII, XVI-XVIII, XXI and XXVII) showed ARI activity with IC50 ranging from 34 to 242 µM. Out of these, two compounds IV and V showed best ARI activity which is comparable with that of quercetin. As a result, two compounds (IV and V) possessing significant dual action (anti-hyperglycaemic and aldose reductase inhibition) were identified and may be used as lead compounds for developing new drugs.

Pyridazinone substituted benzenesulfonamides as potent carbonic anhydrase inhibitors.

A series of sulfonamide derivatives (2a-l) incorporating substituted pyridazinone moieties were investigated for the inhibition of two human cytosolic carbonic anhydrase isoforms, hCA I and hCA II. All these compounds, together with the clinically used sulfonamide acetazolamide were investigated as inhibitors of the physiologically relevant isozymes I and II. These sulfonamides showed very strong inhibition against all these isoforms with K(I)'s in the range of 0.98-8.5 nM which makes such molecules possible to be used as leads for discovery of novel effective CA inhibitors targeting other isoforms with medicinal chemistry applications.

Synthesis and Biological Evaluation of New Phthalazinone Derivatives as Anti-Inflammatory and Anti-Proliferative Agents.

The chemistry of phthalazine derivatives has been of increasing interest since many of these compounds have found many chemotherapeutic applications. So this study aims to synthesize a library of phthalazine derivatives and to investigate their anti-inflammatory and anti-proliferative activities. Sixteen new phthalazinone derivatives (2a-p) were synthesized and tested for their in vitro antiproliferative and in vivo anti-inflammatory activities. All the synthesized compounds were identified and characterized by IR, (1) H NMR, (13) C NMR spectroscopy, and MS. Two compounds, 2b and 2i, showed significant anti-inflammatory activity comparable with that of the standard drug etoricoxib in the carrageenan-induced rat paw edema model at 3 and 5 h, respectively. Three compounds (2h, 2j, and 2g) showed moderate sensitivity toward the renal cancer cell line UO-31.

Synthesis and biological evaluation of some new pyrazoline substituted benzenesulfonylurea/thiourea derivatives as anti-hyperglycaemic agents and aldose reductase inhibitors.

Seventeen new pyrazoline substituted benzenesulfonylurea/thiourea derivatives (2a-q) were synthesized and characterized by elemental analysis and various spectroscopic techniques viz; IR, (1)H NMR, (13)C NMR, and MS data. Thirteen compounds showed moderate to good anti-hyperglycaemic activity in glucose fed hyperglycaemic normal rats at the dose of 0.05 mM/kg b.w. On the basis of docking results nine compounds (2a, 2c, 2e, 2h, 2k, 2l, 2n, 2o and 2q) were evaluated for their ability to inhibit rat lens aldose reductase. Out of these six compounds (2h, 2k, 2l, 2n, 2o and 2q) were found more effective than the known ARI sorbinil. Five compounds (2h, 2k, 2l, 2n and 2o) showed significant dual action (anti-hyperglycaemic and aldose reductase inhibition).

Synthesis and evaluation of some new pyrazoline substituted benzenesulfonylureas as potential antiproliferative agents.

Twenty six new pyrazoline substituted benzenesulfonylureas (2a-z) were synthesized and tested for in vitro anticancer activity. Fourteen derivatives (2i, 2k-2p, 2r, 2s-2x) were screened for their antiproliferative activity towards 60 human cancer cell lines by the National Cancer Institute (USA). Among them four compounds (2i, 2n, 2v and 2x) exhibited significant growth inhibition and further screened at 10-fold dilutions of five different concentrations (0.01, 0.1, 1, 10 and 100 µM). The compounds 2i, 2n, 2v and 2x showed effective growth inhibition (GI50 MID) values of 2.62, 3.93, 3.33, 3.74 µM respectively beside cytostatic activity TGI (MG-MID) values of 8.42, 65.80, 24.00 and 36.06 µM respectively. The compound 2i displayed remarkable antiproliferative activity in 8 different cell lines with GI50 less than 2 µM. Compounds 2n, 2v and 2x also displayed good antiproliferative activity against 11, 18 and 14 different cell lines respectively with GI50 less than 3 µM.

Synthesis and blood glucose lowering activity of some novel benzenesulfonylthiourea derivatives substituted with 4-aryl-1-oxophthalazin-2(1H)yl-ones.

Some new benzenesulfonylthiourea derivatives substituted with phthalazones (2a-q) were synthesized by refluxing the appropriate 4-aryl-1-oxophthalazin-2(1H)yl benzenesulfonamides with isothiocyanate in dry acetone over anhydrous K2CO3. All the synthesized compounds were characterized on the basis of IR, (1)H NMR, MS data and elemental analysis. These synthesized compounds (2a-q) at the dose of 20 mg/kg were tested for antihyperglycemic activity in the glucose-fed hyperglycemic normal rat model and among these compounds 2f and 2m showed modest antihyperglycemic activity.

Synthesis, antiproliferative and anti-inflammatory activities of some novel 6-aryl-2-(p-(methanesulfonyl)phenyl)-4,5-dihydropyridazi-3(2H)-ones.

Sixteen new 6-aryl-2-(p-(methanesulfonyl)phenyl)-4,5-dihydropyridazi-3(2H)-ones (2a-p) were synthesized and tested for in vitro anticancer and in vivo anti-inflammatory activities. Eleven (2b, 2d, 2e-j and 2m-p) of the obtained compounds were screened for their antiproliferative activity towards 60 human cancer cell lines by the National Cancer Institute (USA). Compound 2f showed remarkable activity with GI50 less than 1 µM on 36 human tumor cell lines and has been referred to Biological Evaluation Committee (NCI) for advance study. Compound 2g also displayed promising antiproliferative activity against 20 different cell lines with GI50 less than 1 µM. Compounds 2k and 2n were found to have a comparable anti-inflammatory activity to that of standard drug etoricoxib in carrageenan-induced rat hind paw edema model at 5 h.

Synthesis and biological evaluation of 4-arylphthalazones bearing benzenesulfonamide as anti-inflammatory and anti-cancer agents.

Nine 4-arylphthalazones bearing benzenesulfonamide (2a-i) were synthesized by the condensation of the appropriate 2-aroylbenzoic acid (1a-i) and 4-hydrazinobenzenesulfonamide in ethanol. The structures of these compounds were elucidated by elemental analysis, IR, ¹H NMR, ¹³C NMR, and MS spectroscopy. Two compounds, 2b and 2i, showed significant anti-inflammatory activity comparable to that of the standard drug celecoxib in the carrageenan-induced rat paw edema model. These compounds (2b and 2i) had selective inhibitory activity towards the COX-2 enzyme. Compound 2b had a better selectivity ratio (COX-1/COX-2) compared to that of celecoxib and can be used as a novel template for the design of selective COX-2 inhibitors. Compounds 2d and 2i were screened for their antiproliferative activity toward 60 human cancer cell lines by the National Cancer Institute (USA). The compounds 2d and 2i displayed mild activity toward the renal cancer cell line UO-31.

Synthesis and anti-inflammatory activity of celecoxib like compounds.

Nine novel 4-[3-(4-Dimethylamino-phenyl)-5-aryl-4,5-dihydro-pyrazol-1-yl]-benzenesulfonamides (2a-i) were synthesized and evaluated for their anti-inflammatory and antiproliferative activities. These compounds (2a-i) showed moderate to strong anti-inflammatory activity in carrageenan rat paw oedema test. Compounds 2b, 2d and 2g showing comparable anti-inflammatory activity to that of reference drug celecoxib were evaluated for their ulcerogenic and analgesic activities. The effect of 2b, 2d and 2g on the content of NO, TNF-α and PGE2 in exudates from rat paw stimulated by carrageenan was also evaluated. The compound 2c showed considerable antitumor activities against all 60 human tumor cell lines with effective GI50 (MG-MID) value of 3.63 µM. It exhibited maximum activity against melanoma (LOX IMVI and SK-MEL-5) cancer cell lines with GI50 value less than 2 µM.

6-chloro-7-methyl-3', 4'-dimethoxyflavone - a potent selective COX-2 inhibitor.

Some unnatural chalcones (1a-q) and flavones (2a-d) have been synthesized and evaluated for their antiinflammatory activity using carrageenan-induced rat paw edema assay. The flavone 2c (6-Chloro-7-methyl-3', 4'- dimethoxyflavone) had higher anti-inflammatory activity and superior gastrointestinal safety profiles than the reference drug celecoxib. Compound 2c showed almost two times better selective inhibitory activity towards COX-2 enzyme than celecoxib. 2'-Hydroxychalcones (1a-h) showed moderate to strong anti-inflammatory activity (38.6-82.4 % at 3h and 52.4-80.2 % at 5h). Among 2'-methoxychalcones (1i-q) 1k and 1q exhibited maximum activity 82.6% (at 3h) and 84.3% (at 5h) respectively.

Synthesis and evaluation of anticancer activity of some novel 6-aryl-2-(p-sulfamylphenyl)-pyridazin-3(2H)-ones.

A series of novel pyridazinone derivatives bearing benzenesulfonamide moiety (2a-h) has been synthesized by the condensation of appropriate aroylacrylic acid and 4-hydrazinobenzenesulfonamide hydrochloride in ethanol. Five derivatives (2a, 2b, 2d, 2g and 2h) were evaluated for their anticancer activity toward human cancer cell lines by the National Cancer Institute. The 2h showed remarkable activity against SR (leukemia) and NCI-H522 (non-small cell lung) with a GI(50) value of less than 0.1 µM. It also displayed good activity against leukemia (CCRF-CEM, HL-60 (TB), K-562, MOLT-4, RPMI-8226), non-small cell lung cancer (NCI-H460), colon (HCT-116, HCT-15, HT29, KMI2, SW-620), CNS (SF-295), melanoma (MALME-3M, M14, MDA-MB-435 SK-MEL-5), ovarian (OVCAR-3, NCI/ADR-RES) and breast (MCF7) cancer cell lines with a GI(50) less than 1.0 µM. The acute toxicity study of 2h indicated that it is well tolerated intra-peritoneally (400 mg/kg) by athymic nude mice. The 2h may possibly be used as lead compound for developing new anticancer agents.

Synthesis and biological evaluation of some novel sulfamoylphenyl-pyridazinone as anti-inflammatory agents (Part-II * ).

Seven novel 6-aryl-2-(p-sulfamoylphenyl)-4,5-dihydropyridazin-3(2H)-ones (2a-g) were synthesized by the condensation of appropriate aroylpropionic acid and 4-hydrazinobenzenesulfonamide hydrochloride in ethanol. Structure of all compounds have been elucidated by elemental analysis, IR, (1)H NMR, (13)C NMR, DEPT and MS spectrscopy. These compounds were tested for their anti-inflammatory activity in carrageenan-induced rat paw edema model. Compound 2b exhibited anti-inflammatory activity comparable to that of celecoxib (at 5 h). Two other compounds 2d and 2g showed promising anti-inflammatory activity (edema reduction more than 80% at 5 h). These compounds (2b, 2d and 2g) did not produce any ulceration in gastric region.

Synthesis of some new 1,3,5-trisubstituted pyrazolines bearing benzene sulfonamide as anticancer and anti-inflammatory agents.

Thirteen new 2-pyrazoline derivatives bearing benzenesulfonamide moiety (2a-m) were synthesized by condensing appropriate chalcones with 4-hydrazinonbenzenesulfonamide hydrochloride and tested for anticancer and anti-inflammatory actions. According to the protocol of the National Cancer Institute (NCI) in vitro disease-oriented human cells screening panel assay compounds 2b, 2c, 2e, 2f and 2g exhibited considerable antitumor activities against the entire tested tumor cell lines and showed effective growth inhibition GI(50) (MG-MID) values of 2.63, 2.57, 6.61, 3.31 and 2.57µM, respectively, beside a cyclostatic activity TGI (MG-MID) 9.54, 8.51, 24.0, 19.9 and 8.71µM, respectively. Two compounds 2g and 2k showed more potent anti-inflammatory activity than celecoxib at 5h in carrageenan-induced rat paw edema bioassay. These compounds (2g and 2k) proved to have superior gastrointestinal safety profiles as compared to celecoxib, when tested for their ulcerogenic effects. Compounds 2g and 2k showed no inhibition against the enzymatic activity of bovine COX-2 (in vitro).