Challenging the anticolorectal cancer capacity of quinoxaline-based scaffold via triazole ligation unveiled new efficient dual VEGFR-2/MAO-B inhibitors.

Monoamine oxidases (MAOs) and vascular endothelial growth factor receptor-2 (VEGFR-2) are promoters of colorectal cancer (CRC) and central signaling nodes in epithelial-mesenchymal transition (EMT) induced by activating hypoxia-inducible factors (HIFs). Herein, a novel series of rationally designed triazole-tethered quinoxalines were synthesized and evaluated against HCT-116 CRC cells. The tailored scaffolds combine the pharmacophoric themes of both VEGFR-2 inhibitors and MAO inhibitors. All the synthesized derivatives were screened utilizing the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay for their possible cytotoxic effects on normal human colonocytes, then evaluated for their anticancer activities against HCT-116 cells overexpressing MAOs. The hit derivatives 11 and 14 exhibited IC50 = 18.04 and 7.850 µM, respectively, against HCT-116cells within their EC100 doses on normal human colonocytes. Wound healing assay revealed their efficient CRC antimetastatic activities recording HCT-116 cell migration inhibition exceeding 75 %. In vitro enzymatic assays demonstrated that both 11 and 14 efficiently inhibited VEGFR-2 (IC50 = 88.79 and 9.910 nM), MAO-A (IC50 = 0.763 and 629.1 nM) and MAO-B (IC50 = 0.488 and 209.6 nM) with observed MAO-B over MAO-A selectivity (SI = 1.546 and 3.001), respectively. Enzyme kinetics studies were performed for both compounds to identify their mode of MAO-B inhibition. Furthermore, qRT-PCR analysis showed that the hits efficiently downregulated HIF-1α in HCT-116cells by 3.420 and 16.96 folds relative to untreated cells. Docking studies simulated their possible binding modes within the active sites of VEGFR-2 and MAO-B to highlight their essential structural determinants of activities. Finally, they recorded in silico drug-like absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiles as well as ligand efficiency metrics.

Targeting the interplay between MMP-2, CA II and VEGFR-2 via new sulfonamide-tethered isomeric triazole hybrids; Microwave-assisted synthesis, computational studies and evaluation.

Recently, the interest in targeting metalloenzymes is obviously growing for halting various tumor progression events and surmounting the resistance due to routine chemotherapy regimen. In this regard, attention to MMP-2 and CA II has been drawn as validated druggable anticancer targets that share vital signaling pathways. The vast majority of MMP and CA inhibitors are designed to function as directed single-target agents. In spite of their transient efficacy, they are often susceptible to tumor resistance. Hence, several dual inhibitors of correlated MMPs and CAs were introduced. This set the stage to simultaneously target the common vital signaling nodes as well. VEGFR-2 is considered central to various tumorigenesis processes involving both MMP-2 and CA II. Herein, we report concomitant inhibition of MMP-2, CA II, and VEGFR-2 via rationally designed 1,2,3- and 1,2,4-triazole hybrids bearing various sulfonamide appendages following pharmacophore hybridization strategy. The designed adducts were efficiently elaborated in an almost quantitative yield utilizing microwave-assisted click 1,3-dipolar cycloaddition reaction between various alkynes-based 1,2,4-triazole and 4-azido benzensulfonamides. All derivatives were evaluated for their anticancer potential against three human cancer cell lines (Caco-2, MDA-MB-231, and HepG-2) after safety assessment on normal human cells (Wi-38). Amongst those click adducts, 8d and 8e were the most potent and safest anticancer agents exhibiting low range nanomolar IC50 (7.37-11.96 nM) and high selectivity (SI = 3.01-4.46), against the studied cancer cell lines, hence superior to doxorubicin concerning potency (IC50 = 10.63-48.25 nM) and selectivity (SI = 0.43-1.93). They significantly elevated the expression level of the tumor suppressor p53 in the three tested cancer cell lines up to 3 folds and induced apoptosis in HepG-2 cells with higher potential to 8d over 8e. Enzymatic evaluation showed that both derivatives were potent dual MMP-2/VEGFR-2 inhibitors, particularly 8d (MMP-2; IC50 = 5.66 nM and VEGFR-2; IC50 = 6.65 nM), relative to the reference MMP-2 inhibitor NNGH (IC50 = 299.50 nM) and VEGFR-2 inhibitor sorafenib (IC50 = 4.92 nM). Both 8d and 8e exhibited relatively moderate activity against the human CA II isoform (IC50 = 116.9 and 187.5 nM, respectively) relative to the reference (IC50 = 27.3 nM). Docking studies clearly explained the superior in vitro enzymatic inhibition profiles of 8d over 8e and predicted the structural determinants of activity. Nevertheless, 8d displayed promising in silico ADMET properties and ligand efficiency metrics. These findings evidently demonstrated the sulfatriazole 8d as an auspicious multi-target-directed ligand that deserves further optimization for developing novel antitumor agents.

Synthesis, modeling and biological evaluation of some pyrazolo[3,4-d]pyrimidinones and pyrazolo[4,3-e][1,2,4]triazolo[4,3-a]pyrimidinones as anti-inflammatory agents.

New pyrazolo[3,4-d]pyrimidinone and pyrazolo[4,3-e][1,2,4]triazolo[4,3-a]pyrimidinone derivatives were synthesized. They have been evaluated for their anti-inflammatory activity using in vitro (COX-1/COX-2) inhibitory assay. Moreover, compounds with promising in vitro activity and COX-1/COX-2 selectivity indices were subjected for in vivo anti-inflammatory testing using formalin induced paw edema and cotton-pellet induced granuloma assays for acute and chronic models, respectively. Compounds (2c, 3i, 6a, 8 and 12) showed promising COX-2 inhibitory activity and high selectivity compared to celecoxib. Most of the compounds exhibited potential anti-inflammatory activity for both in vivo acute and chronic models. Almost all compounds displayed safe gastrointestinal profile and low ulcerogenic potential guided by histopathological examination. Furthermore, molecular docking experiments rationalized the observed in vitro anti-inflammatory activity of selected candidates. In silico predictions of the pharmacokinetic and drug-likeness properties recommended accepted profiles of the majority of compounds. In conclusion, this work provides an extension of the chemical space of pyrazolopyrimidinone and pyrazolotriazolopyrimidinone chemotypes for the anti-inflammatory activity.

Design, synthesis and evaluation of some pyrazolo[3,4-d]pyrimidine derivatives bearing thiazolidinone moiety as anti-inflammatory agents.

Two new series of pyrazolo[3,4-d]pyrimidine bearing thiazolidinone moiety were designed and synthesized. The newly synthesized compounds were evaluated for their in vitro (COX-1 and COX-2) inhibitory assay. Compounds that showed promising COX-2 selectivity were further subjected to in vivo anti-inflammatory screening applying formalin induced paw edema (acute model) and cotton-pellet induced granuloma (chronic model) assays using celecoxib and diclofenac sodium as reference drugs. The histopathological and ulcerogenic potential were also determined. In vivo anti-inflammatory data showed that compounds 2, 6, 7d displayed anti-inflammatory activity higher than both references in the formalin induced paw edema model. On the other hand, compounds 2, 3d, 3e, 7b and 7d displayed anti-inflammatory activity greater than or nearly equivalent to diclofenac sodium in the cotton pellet-induced granuloma assay. Moreover, most of the tested compounds revealed good gastrointestinal safety profile. Collectively, compounds 2 and 7d were considered as promising candidates in managing both acute and chronic inflammation with safe gastrointestinal margin.

Design, synthesis and evaluation of some pyrazolo[3,4-d]pyrimidines as anti-inflammatory agents.

New pyrazolo[3,4-d]pyrimidines substituted with various functionalities or attached to a substituted pyrazole ring through different linkages were synthesized. The synthesized compounds were evaluated for their anti-inflammatory activity using in vitro COX-1/COX-2 inhibition assay and in vivo formalin induced paw edema and cotton pellet-induced granuloma assays. Results revealed that compounds 17b and 18 possessed COX-1/COX-2 selectivity indices higher than diclofenac sodium and celecoxib. However, compounds 16a,b exhibited selectivity indices higher than diclofenac sodium and nearly equivalent to celecoxib, whereas, 9b displayed selectivity index comparable to diclofenac sodium. In vivo anti-inflammatory data showed that compounds 9b, 16a, 18 displayed anti-inflammatory activity higher than both references in the formalin induced paw edema model. On the other hand, the pyrazolyl derivatives 9b, 16b and 17b displayed anti-inflammatory activity about 2-2.5-fold that of diclofenac sodium and nearly 8-10.5-fold that of celecoxib in the cotton pellet-induced granuloma assay. The ulcerogenic effect of the active compounds was also investigated and results revealed that compounds 16a, 17a,b and 18 showed good gastrointestinal safety profile. Based on this, compounds 16a and 18 were considered as safe and effective leads in managing acute inflammation, while, 17b was prominent in controlling chronic inflammation.