Synthesis, spectroscopic, topological, hirshfeld surface analysis, and anti-covid-19 molecular docking investigation of isopropyl 1-benzoyl-4-(benzoyloxy)-2,6-diphenyl-1,2,5,6-tetrahydropyridine-3-carboxylate.

Isopropyl 1-benzoyl-4-(benzoyloxy)-2,6-diphenyl-1,2,5,6-tetrahydropyridine-3-carboxylate (IDPC) was synthesized and characterized via spectroscopic (FT-IR and NMR) techniques. Hirshfeld surface and topological analyses were conducted to study structural and molecular properties. The energy gap (Eg), frontier orbital energies (EHOMO, ELUMO) and reactivity parameters (like chemical hardness and global hardness) were calculated using density functional theory with B3LYP/6-311++G (d,p) level of theory. Molecular docking of IDPC at the active sites of SARS-COVID receptors was investigated. IDPC molecule crystallized in the centrosymmetric triclinic ( P 1 ¯ ) space group. The topological and Hirshfeld surface analysis revealed that covalent, non-covalent and intermolecular H-bonding interactions, and electron delocalization exist in the molecular framework. Higher binding score (-6.966 kcal/mol) of IDPC at the active site of SARS-COVID main protease compared to other proteases suggests that IDPC has the potential of blocking polyprotein maturation. H-bonding and π-cationic and interactions of the phenyl ring and carbonyl oxygen of the ligand indicate the effective inhibiting potential of the compound against the virus.

Synthesis of 4-methyl-N'-(3-alkyl-2r,6c-diarylpiperidin-4-ylidene)-1,2,3-thiadiazole-5-carbohydrazides with antioxidant, antitumor and antimicrobial activities.

The structures of the newly synthesized 4-methyl-N'-(3-alkyl-2r,6c-diarylpiperidin-4-ylidene)-1,2,3-thiadiazole-5-carbohydrazide (5a­5l) were confirmed by spectral and elemental analysis. The difference in the potency of activity against various free radicals, human cancer cells and microbial strains has been evaluated by SAR. Compounds with electron-donating methoxy (5i and 5c) and methyl (5h and 5b) substitutions at the para position of the phenyl showed excellent free radical scavenging effects. In the tested compounds, electron withdrawing fluoro (5k and 5e), chloro (5j and 5d), and bromo (5l and 5f) substitution at the para position of the phenyl ring attached to C-2 and C-6 carbons of the piperidine moiety outperformed cytotoxic and antimicrobial activities. Our findings suggest that the antioxidant, anti-tumor and anti-microbial activities of compounds 5a­5l create promising leads for the development of potent anti-tumor and anti-microbial agents.