Diabetes mellitus (DM) is a multifaceted metabolic disorder that remains a major threat to global health security. Sadly, the clinical relevance of available drugs is burdened with an upsurge in adverse effects; hence, inhibiting the carbohydrate-hydrolyzing enzymes α-glucosidase and α-amylase while preventing oxidative stress is deemed a practicable strategy for regulating postprandial glucose levels in DM patients. We report herein the α-glucosidase and α-amylase inhibition and antioxidant profile of quinoline hybrids 4a–t and 12a–t bearing 1,3,4-oxadiazole and 1,2,3-triazole cores, respectively. Overall, compound 4i with a bromopentyl sidechain exhibited the strongest α-glucosidase inhibition (IC₅₀ = 15.85 µM) relative to reference drug acarbose (IC₅₀ = 17.85 µM) and the best antioxidant profile in FRAP, DPPH, and NO scavenging assays. Compounds 4a and 12g also emerged as the most potent NO scavengers (IC₅₀ = 2.67 and 3.01 µM, respectively) compared to gallic acid (IC₅₀ = 728.68 µM), while notable α-glucosidase inhibition was observed for p-fluorobenzyl compound 4k (IC₅₀ = 23.69 µM) and phenyl-1,2,3-triazolyl compound 12k (IC₅₀ = 22.47 µM). Moreover, kinetic studies established the mode of α-glucosidase inhibition as non-competitive, thus classifying the quinoline hybrids as allosteric inhibitors. Molecular docking and molecular dynamics simulations then provided insights into the protein–ligand interaction profile and the stable complexation of promising hybrids at the allosteric site of α-glucosidase. These results showcase these compounds as worthy scaffolds for developing more potent α-glucosidase inhibitors with antioxidant activity for effective DM management.

A series of triclosan azo-adducts were synthesized to investigate their structure-activity relationship against Mycobacterium tuberculosis and non-tuberculous mycobacteria. The series' most potent compound was four and sixteen times more active than triclosan and rifabutin against drug-resistant Mycobacterium abscessus, respectively, while being less cytotoxic to human macrophages than triclosan on day one. Additionally, one of the azo-adducts was twice as efficient against M. tuberculosis as triclosan and twice as effective against Mycobacterium marinum as isoniazid. Furthermore, the synthesized azo-adducts were equally effective against M. abscessus strains overexpressing InhA, suggesting that these compounds work through a distinct mechanism.

A series of INH–pyrazole molecular hybrids (6a–o) was synthesized and evaluated for in vitro anti-tubercular activity against drug-susceptible, multidrug-resistant (MDR), and extensively drug-resistant (XDR) Mycobacterium tuberculosis strains, alongside their corresponding precursors (4a–o), using isoniazid (INH) as the reference drug. Overall, the hybrid compounds exhibited inhibitory activity comparable to or exceeding that of INH against the drug-susceptible strain. Among the series, compounds 6a, 6d–6f, and 6m demonstrated the highest potency, with a minimum inhibitory concentration (MIC) of 0.9 µM, corresponding to an approximately 4.3-fold enhancement relative to INH. Compounds 6b,c, 6g–i, and 6l,m also showed noticeable activity (MIC = 1.95 µM), representing an approximate twofold improvement over INH and significantly outperforming their respective precursors. Notably, compound 6o exhibited enhanced activity against the XDR strain (MIC = 121 µM), reflecting an approximately 2.8-fold improvement compared to precursor 4o (MIC > 341 µM), thereby highlighting the advantage of molecular hybridization. However, all compounds displayed diminished activity relative to INH against the resistant strains. Against the MDR strain, compounds 4h, 6e, and 6g displayed measurable activity, with MIC values of 76, 125, and 112 µM, respectively. Cytotoxicity assessment using THP-1 human monocytic cells revealed low toxicity, with all tested compounds maintaining acceptable cell viability at 10 µg/mL. In addition, in silico ADME analysis indicated that the hybrid molecules comply with key drug-likeness criteria. Collectively, these findings suggest that INH–pyrazole hybrids represent promising lead scaffolds for the development of next-generation anti-tubercular agents.