Synthesis, crystal structure and in-silico evaluation of arylsulfonamide Schiff bases for potential activity against colon cancer

This report presents a comprehensive investigation into the synthesis and characterization of Schiff base compounds derived from benzenesulfonamide. The synthesis process, involved the reaction between N-cycloamino-2-sulfanilamide and various substituted o-salicylaldehydes, resulted in a set of compounds that were subjected to rigorous characterization using advanced spectral techniques, including 1H NMR, 13C NMR and FT-IR spectroscopy, and single-crystal X-ray diffraction. Furthermore, an in-depth assessment of the synthesized compounds was conducted through Absorption, Distribution, Metabolism, Excretion and Toxicity (ADMET) analysis, in conjunction with docking studies, to elucidate their pharmacokinetic profiles and potential. Impressively, the ADMET analysis showcased encouraging drug-likeness properties of the newly synthesized Schiff bases. These computational findings were substantiated by molecular properties derived from density functional theory (DFT) calculations using the B3LYP/6-31G* method within the Jaguar Module of Schrödinger 2023-2 from Maestro (Schrodinger LLC, New York, USA). The exploration of frontier molecular orbitals (HOMO and LUMO) enabled the computation of global reactivity descriptors (GRDs), encompassing charge separation (Egap) and global softness (S). Notably, within this analysis, one Schiff base, namely, 4-bromo-2-{N-[2-(pyrrolidine-1-sulfonyl)phenyl]carboximidoyl}phenol, 20, emerged with the smallest charge separation (ΔEgap = 3.5780 eV), signifying heightened potential for biological properties. Conversely, 4-bromo-2-{N-[2-(piperidine-1-sulfonyl)phenyl]carboximidoyl}phenol, 17, exhibited the largest charge separation (ΔEgap = 4.9242 eV), implying a relatively lower propensity for biological activity. Moreover, the synthesized Schiff bases displayed remarkeable inhibition of tankyrase poly(ADP-ribose) polymerase enzymes, integral in colon cancer, surpassing the efficacy of a standard drug used for the same purpose. Additionally, their bioavailability scores aligned closely with established medications such as trifluridine and 5-fluorouracil. The exploration of molecular electrostatic potential through colour mapping delved into the electronic behaviour and reactivity tendencies intrinsic to this diverse range of molecules.

Evaluation of the In Vitro Antifungal Activity of Novel Arylsulfonamides against Candida spp

The antifungal activity of molecules belonging to the arylsulfonamide chemotype has previously been demonstrated. Here, we screened arylsulfonamide-type compounds against a range of Candida spp. and further established the structure-activity relationship based on a "hit compound". A series of four sulfonamide-based compounds, N-(4-sulfamoylbenzyl) biphenyl-4-carboxamide (3), 2,2-diphenyl-N-(4-sulfamoylbenzyl) acetamide (4), N-(4-sulfamoylphenethyl) biphenyl-4-carboxamide (5) and 2,2-diphenyl-N-(4-sulfamoylphenethyl) acetamide (6), were tested against the American Type Culture Collection (ATCC) and clinical strains of C. albicans, C. parapsilosis and C. glabrata. Based on the fungistatic potential of prototype 3, a further subset of compounds, structurally related to hit compound 3, was synthesized and tested: two benzamides (10-11), the related amine 4-[[(4-4-((biphenyl-4-ylmethylamino)methyl) benzenesulfonamide (13) and the corresponding hydrochloride, 13^.HCl. Both amine 13 and its hydrochloride salt had fungicidal effects against Candida glabrata strain 33 (MFC of 1.000 mg/mL). An indifferent effect was detected in the association of the compounds with amphotericin B and fluconazole. The cytotoxicity of the active compounds was also evaluated. This data could be useful to develop novel therapeutics for topical use against fungal infections.

Discovery of Arylsulfonamide Nav1.7 Inhibitors: IVIVC, MPO Methods, and Optimization of Selectivity Profile

The voltage-gated sodium channel Nav1.7 continues to be a high-profile target for the treatment of various pain afflictions due to its strong human genetic validation. While isoform selective molecules have been discovered and advanced into the clinic, to date, this target has yet to bear fruit in the form of marketed therapeutics for the treatment of pain. Lead optimization efforts over the past decade have focused on selectivity over Nav1.5 due to its link to cardiac side effects as well as the translation of preclinical efficacy to man. Inhibition of Nav1.6 was recently reported to yield potential respiratory side effects preclinically, and this finding necessitated a modified target selectivity profile. Herein, we report the continued optimization of a novel series of arylsulfonamide Nav1.7 inhibitors to afford improved selectivity over Nav1.6 while maintaining rodent oral bioavailability through the use of a novel multiparameter optimization (MPO) paradigm. We also report in vitro-in vivo correlations from Nav1.7 electrophysiology protocols to preclinical models of efficacy to assist in projecting clinical doses. These efforts produced inhibitors such as compound 19 with potency against Nav1.7, selectivity over Nav1.5 and Nav1.6, and efficacy in behavioral models of pain in rodents as well as inhibition of rhesus olfactory response indicative of target modulation.

Novel Donepezil-Arylsulfonamide Hybrids as Multitarget-Directed Ligands for Potential Treatment of Alzheimer's Disease

Alzheimer’s disease (AD) is one of the most devastating neurodegenerative disorders, characterized by multiple pathological features. Therefore, multi-target drug discovery has been one of the most active fields searching for new effective anti-AD therapies. Herein, a series of hybrid compounds are reported which were designed and developed by combining an aryl-sulfonamide function with a benzyl-piperidine moiety, the pharmacophore of donepezil (a current anti-AD acetylcholinesterase AChE inhibitor drug) or its benzyl-piperazine analogue. The in vitro results indicate that some of these hybrids achieve optimized activity towards two main AD targets, by displaying excellent AChE inhibitory potencies, as well as the capability to prevent amyloid-β (Aβ) aggregation. Some of these hybrids also prevented Aβ-induced cell toxicity. Significantly, drug-like properties were predicted, including for blood-brain permeability. Compound 9 emerged as a promising multi-target lead compound (AChE inhibition (IC₅₀ 1.6 μM); Aβ aggregation inhibition 60.7%). Overall, this family of hybrids is worthy of further exploration, due to the wide biological activity of sulfonamides.

Mechanism and Potential Inhibitors of GlmU: A Novel Target for Antimicrobial Drug Discovery

BACKGROUND

Multidrug resistant Gram negative pathogens pose a persistent threat to the health care system and require investigation of new targets and molecules for the development of antibiotics to treat infections caused by MDR bacterial pathogens.

OBJECTIVE

It is essential to work on multidisciplinary approaches and diverse strategies for developing new compounds acting on novel antibacterial targets. N-acetylglucosamine-1-phosphateuridyltransferase/ glucosamine-1-phosphate-acetyltransferase (GlmU) is one such target which is involved in the synthesis of both peptidoglycan and Lipopolysaccharide in Gram negative and Gram positive bacteria making GlmU an attractive target for developing antibacterials.

RESULTS

GlmU, as revealed by X- ray crystallographic studies, is made up of two domains connected by α helical arm; the N-terminal uridyltransferase domain resembles a dinucleotide Rossmann fold and the C- terminal acetyltransferase domain adopts a left handed parallel β helix structure. The GlmU molecules are arranged in a trimeric array, the acetyltransferase active site being formed at the junction of adjacent LβH domain. Many potent inhibitors of both the acetyltransferase and uridyltransferase activity of GlmU have been identified. Inhibitors of the acetyltransferase activity of GlmU include nonspecific thiol reactive agents, 2-phenylbenzofurans, arylamines and arylsulfonamides. A aminopiperidine based inhibitor has also been reported to inhibit uridyltransferase activity of hiGlmU.

CONCLUSION

The present review provides an insight of the structure of GlmU and its reported inhibitors which make GlmU a potential target for drug designing. The GlmU is a promising target for drug discovery against Gram negative pathogens and future studies should focus on GlmU for the development of more potent compounds for treating Gram negative infections.

Identification of Loop D Domain Amino Acids in the Human Aquaporin-1 Channel Involved in Activation of the Ionic Conductance and Inhibition by AqB011

Aquaporins are integral proteins that facilitate the transmembrane transport of water and small solutes. In addition to enabling water flux, mammalian Aquaporin-1 (AQP1) channels activated by cyclic GMP can carry non-selective monovalent cation currents, selectively blocked by arylsulfonamide compounds AqB007 (IC₅₀ 170 μM) and AqB011 (IC₅₀ 14 μM). In silico models suggested that ligand docking might involve the cytoplasmic loop D (between AQP1 transmembrane domains 4 and 5), but the predicted site of interaction remained to be tested. Work here shows that mutagenesis of two conserved arginine residues in loop D slowed the activation of the AQP1 ion conductance and impaired the sensitivity of the channel to block by AqB011. Substitution of residues in loop D with proline showed effects on ion conductance amplitude that varied with position, suggesting that the structural conformation of loop D is important for AQP1 channel gating. Human AQP1 wild type, AQP1 mutant channels with alanines substituted for two arginines (R159A+R160A), and mutants with proline substituted for single residues threonine (T157P), aspartate (D158P), arginine (R159P, R160P), or glycine (G165P) were expressed in Xenopus laevis oocytes. Conductance responses were analyzed by two-electrode voltage clamp. Optical osmotic swelling assays and confocal microscopy were used to confirm mutant and wild type AQP1-expressing oocytes were expressed in the plasma membrane. After application of membrane-permeable cGMP, R159A+R160A channels had a significantly slower rate of activation as compared with wild type, consistent with impaired gating. AQP1 R159A+R160A channels showed no significant block by AqB011 at 50 μM, in contrast to the wild type channel which was blocked effectively. T157P, D158P, and R160P mutations had impaired activation compared to wild type; R159P showed no significant effect; and G165P appeared to augment the conductance amplitude. These findings provide evidence for the role of the loop D as a gating domain for AQP1 ion channels, and identify the likely site of interaction of AqB011 in the proximal loop D sequence.

A novel small-molecule arylsulfonamide causes energetic stress and suppresses breast and lung tumor growth and metastasis

Neoplastic cells display reprogrammed metabolism due to the heightened energetic demands and the need for biomass synthesis of a growing tumor. Targeting metabolic vulnerabilities is thus an important goal for cancer therapy. Here, we describe a novel small-molecule arylsulfonamide (N-cyclobutyl-N-((2,2-dimethyl-2H-pyrano[3,2-b]pyridin-6-yl)methyl)-3,4-dimethoxybenzenesulfonamide) that exerts potent cytotoxicity and energetic stress on tumor cells while largely sparing non-cancerous human cells. In tumor cells, it stimulates glycolysis and accelerates glucose consumption. Consequently, intracellular ATP levels plummet, triggering activation of AMP-activated protein kinase (AMPK), and diminishing the mammalian target of rapamycin complex 1 (mTORC1) and hypoxia-inducible factor 1 (HIF-1) signaling. In orthotopic triple-negative breast cancer and subcutaneous lung cancer mouse models, this arylsulfonamide robustly suppresses primary tumor growth, inhibits the formation of distant metastases to the lung, and extends mouse survival while being very well tolerated. These therapeutic effects are further potentiated by co-administration of 2-deoxy-D-glucose (2-DG), a glucose analog and glycolysis inhibitor. Collectively, our findings provide preclinical proof of concept for the further development of this arylsulfonamide in combination with 2-DG towards cancer treatment.

Design, synthesis, and in vitro antiproliferative and kinase inhibitory effects of pyrimidinylpyrazole derivatives terminating with arylsulfonamido or cyclic sulfamide substituents

A novel series of substituted pyrimidine compounds bearing N-phenylpyrazole and terminating with aryl and cyclic sulfonamido moiety were designed, synthesized, and evaluated in vitro as antiproliferative agents against a panel of 53 cell lines of different tissues at the NCI. Among them, compound 1d with p-chlorobenzenesulfonamido terminal moiety, ethylene spacer, and 4-chloro-3-methoxyphenyl ring at position 3 of the pyrazole nucleus showed the highest mean percentage inhibition value over the whole cancer cell line panel at 10 μM concentration. It showed broad-spectrum antiproliferative activity over many cell lines of different cancer types. For instance, compound 1d inhibited the growth of HL-60 (TB), SR leukemia, and T-47D and MCF-7 breast cancer cell line by 135.92%, 119.44%, 95.32%, and 82.03% at 10 μM, respectively. And it inhibited the growth of COLO 205 colon, HT29 colon, BT-549 breast, and ACHN renal cancer cell lines by more than 80% at the same test concentration. However, testing compound 1d upon determining its IC₅₀ against the most sensitive cell lines showed to good extent selectivity against HT29 colon cancer cell line than HL-60 leukemia and MRC-5 lung fibroblasts (normal cells). Compound 1d was further tested against 12 kinases of different kinase families, and the highest inhibitory effect was exerted against RAF1, V600E-B-RAF, and V600K-B-RAF kinases.