Medicinal Chemistry - Volume 19, Issue 2, 2023

Cancer is an uncontrolled, abnormal growth of cells and the second cause of death after cardiovascular disease. At present, chemotherapy and related drugs have three major categories. All three have characteristic action and toxicity levels of antitumor activity. Due to indications of unwanted side effects, the exploration of novel and selective anticancer agents is crucially required. Heterocyclic compounds have always played a major role in research for new drug discovery and development. 1,3,4-oxadiazole derivatives are heterocyclic isomers having pharmacological properties and play an important role as antiproliferative agents. The present review summarizes anticancer activities of 1,3,4-oxadiazole derivatives against different cell lines, such as HCT-116, MCF-7, HeLa, SMMC-7721, and A549. The results showed that 1,3,4-oxadiazole and its derivatives have the potential to play a major role as an anticancer agent with fewer side effects.

Background: Understanding the cognitive and behavioral aspects of Alzheimer's disease- related dementia is surely a sturdy task to deal with. In recent years, a broad search for novel anti-Alzheimer agents has been continuously conducted. The malfunctioning of various neurotransmitter systems and the accumulation of abnormal proteins in the brain are the two key characteristics of this disorder. This is supported by a growing amount of evidence. Some Pharmacophoric groups/combinations exhibit potential neuroprotective activity. Methods: This study aims to compile the most recent and interesting target/target combinations/ pharmacophoric combinations to cure Alzheimer's disease. We concentrated our efforts to find the ability of certain pharmacophoric elements to interfere with various enzymatic and/or receptor systems or to work as neuroprotective agents. These pharmacophoric elements may be proved to be promising leads for future multi-target anti-Alzheimer drug discovery programs. Results: Anticholinesterase drugs were mentioned as the best treatment thus far. Additionally, impairments in the serotonergic, GABAergic, noradrenergic, dopaminergic, and glutaminergic and a few other pathways have all been linked to memory, speech, behavioral and other alterations in Alzheimer's disease. Conclusion: This includes the study of workable pharmacophoric groups/combinations, receptors/ enzymatic systems and related hypotheses to find the promising therapeutic lead compounds which could work as future anti-Alzheimer drugs. We discuss future work that would improve our understanding of this Disease.

Background: The role of Zn(II) in storage, insulin secretion and function has been documented, while plant phenolics have antioxidant and other pharmacological credence. Objective: The study aimed at synthesizing a novel medicinal Zn(II) complex. The medicinal properties of zinc(II) and caffeic acid were considered in synthesizing a novel complex with promising and improved antioxidant and anti-hyperglycaemic attributes. Methods: Complex synthesis was done using a 1:2 molar ratio of zinc acetate and caffeic acid and structurally characterized using NMR, FT-IR, high resolution-mass spectroscopy and HPLC. Its cellular toxicity was assessed in Chang liver cells and L-myotubes. In vitro, cellular, and isolated tissue models were used to evaluate the antioxidant and anti-hyperglycaemic properties of the complex relative to its precursors. Molecular docking was used to investigate the interaction with insulin signalling target proteins: GLUT-4 and protein kinase B (Akt/PKB). Results: Zinc(II) and caffeic acid interacted via Zn:O4 coordination, with the complex having one moiety of Zn(II) and 2 moieties of caffeic acid. The complex showed in vitro radical scavenging, α- glucosidase and α-amylase inhibitory activity up to 2.6 folds stronger than caffeic acid. The ability to inhibit lipid peroxidation (IC50 = 26.4 μM) and GSH depletion (IC50 = 16.8 μM) in hepatocytes was comparable to that of ascorbic acid (IC50 = 24.5 and 29.2 μM) and about 2 folds stronger than caffeic acid. Complexation improved glucose uptake activity of caffeic acid in L-6 myotubes (EC50 = 23.4 versus 169 μM) and isolated rat muscle tissues (EC50 = 339 versus 603 μM). Molecular docking showed better interaction with insulin signalling target proteins (GLUT-4 and Akt/PKB) than caffeic acid. The complex was not hepatotoxic or myotoxic. Conclusion: Data suggest a synergistic antioxidant and anti-hyperglycaemic potential between zinc and caffeic acid, which could be attributed to the Zn:O4 coordination. Thus, it may be of medicinal relevance.

Background: Inflammation is a protective biological process, but under extreme conditions, it can become highly dreadful to the body. Antioxidant and anti-inflammatory agents treat similar disease conditions as inflammation and oxidative stress commonly follow similar causative pathways. Objective: The goal of this study was to synthesize N-substituted indole derivatives with different heterocyclic moieties through propyl linker with the aim of getting highly potent anti-inflammatory and antioxidant agents. Methods: Synthesized compounds were analyzed by analytical techniques such as IR, ¹H NMR, ¹³C NMR spectra, and mass spectrometry. Molecular docking and ADME calculation were employed on synthesized compounds to estimate their COX-2 enzyme inhibition and drug like properties, respectively. Antioxidant activity was evaluated by the DPPH assay and the reducing power assay. Selected derivatives were evaluated for anti-inflammatory activity at an acute (carrageenan-induced paw edema method) and chronic level (formalin-induced inflammation method) using indomethacin as a standard drug. Results: Herein, twelve indole derivatives (11a-c, 12a-c, 13a-c, and 14a-c) were synthesized. Among all, compound 12c was found to be the best inhibitor of the COX-2 enzyme as it displayed good interaction energy. Zero violations of Lipinski's rule were found in the ADME investigation, confirming the drug-like qualities of synthesized compounds. The compounds 11a and 12c were found to be the most potent as compared with standard ascorbic acid in antioxidant evaluation. From the collected results, compounds 12c and 13b were the most potent against acute and chronic inflammation. Conclusion: The novel synthetic indole derivatives could act as potent leads for the development of novel antioxidant and anti-inflammatory agents.

Introduction: An analysis of the literature on the painkillers long used in traditional medicine, which are isolated from plant materials, has shown that many of them are alkylamides of various carboxylic acids. This fact served as the basis for the study of a large group of N-alkyl-4- methyl-2,2-dioxo-1H-2λ⁶,1-benzothiazine-3-carboxamides as potential new analgesics. The objects of the study were synthesized in the traditional way involving the initial conversion of 4-methyl- 2,2-dioxo-1H-2λ⁶,1- benzothiazine-3-carboxylic acid to imidazolide, in which imidazolide was used as an acylating agent. The method is simple to implement and, as a rule, gives high yields of final alkylamides. However, in reaction with sterically hindered tert-butylamine, along with the “normal” product, an unexpected formation of N-tert-butyl-4-methyl-1-(4-methyl-2,2-dioxo-1H-2λ⁶,1- benzothiazine-3-carbonyl)-2,2-dioxo-2λ⁶,1-benzothiazine-3-carboxamide was observed, which was characterized by X-ray diffraction analysis as a monosolvate with N,N-dimethylformamide. These synthetic problems can be avoided using a more powerful acylating agent, 4-methyl-2,2-dioxo-1H- 2λ⁶,1- benzothiazine-3-carbonyl chloride. Background: A large group of new N-alkyl-4-methyl-2,2-dioxo-1H-2λ⁶,1-benzothiazine-3- carboxamides was synthesized. Objective: On the basis of molecular docking, some derivatives of N-alkyl-4-methyl-2,2-dioxo-1H- 2λ⁶,1-benzothiazine-3-carboxamides have been designed. Their preliminary structure-activity relationships (SAR) have been studied. The most rational approaches to the synthesis of lead compounds have been developed. The most active compounds have shown high anti-inflammatory and analgesic activities. Methods: The structure of all compounds prepared has been confirmed by the data of elemental analysis, 1H- and 13C NMR spectroscopy, and electrospray ionization liquid chromato-mass spectrometry. For rational drug design, optimization of further pharmacological screening and prediction of a possible mechanism of pharmacological action, molecular docking has been performed. For the determination of activity, pharmacological studies have been carried out. Results: Pharmacological tests have determined that the transition from N-aryl(heteroaryl) alkylamides to “pure” N-alkylamides we carried out is accompanied by a significant reduction and even complete loss of anti-inflammatory effect with remaining analgesic activity. Conclusion: According to the studies, compounds from N-alkyl-4-methyl-2,2-dioxo-1H-2λ⁶,1- benzothiazine-3-carboxamides are potential anti-inflammatory and analgesic agents.

Aims: To synthesize novel sulfonamide inhibitors of carbonic anhydrase and develop in vitro prioritization workflow to select compounds for in vivo evaluation. Background: Carbonic anhydrase (CA) inhibitors gain significant attention in the context of drug discovery research for glaucoma, hypoxic malignancies, and bacterial infections. In previous works, we have successfully used direct sulfochlorination approach to develop diverse heterocyclic primary sulfonamides with remarkable activity and selectivity against therapeutically relevant CA isoforms. Objective: Synthesis and investigation of the CA inhibitory properties of novel trifluoromethylisoxazolyl- and trifluoromethylpyrazolyl-substituted (hetero)aromatic sulfonamides. Methods: Thirteen trifluoromethylisoxazolyl- and thirteen trifluoromethylpyrazolyl-substituted (hetero) aromatic sulfonamides were synthesized by direct sulfochlorination of hydroxyisoxazolines and pyrazoles followed by reaction with ammonia. The compound structures were confirmed by ¹H and ¹³C NMR as well as element analysis. The obtained compounds were evaluated, using the CA esterase activity assay, for their potential to block the catalytic activity of bovine CA (bCA). Results: Eight most potent compounds selected based on the esterase activity assay data were tested for direct affinity to the enzyme using the thermal shift assay (TSA). These compounds displayed Kd values (measured by TSA) in the double-digit nanomolar range, thus showing comparable activity to the reference drug acetazolamide. Conclusion: Coupling the bCA esterase activity assay with thermal shift assay represents a streamlined and economical strategy for the prioritization of sulfonamide CA inhibitors for subsequent evaluation in vivo.