Novel silver(I) N ‐heterocyclic carbene complexes bearing 2‐(4‐hydroxyphenyl)ethyl group: Synthesis, characterization, and enzyme inhibition properties

Chemistry of heterocycles as carbonic anhydrase inhibitors: A pathway to novel research in medicinal chemistry review

Nowadays, the scientific community has focused on dealing with different kinds of diseases by exploring the chemistry of various heterocycles as novel drugs. In this connection, medicinal chemists identified carbonic anhydrases (CA) as one of the biologically active targets for curing various diseases. The widespread distribution of these enzymes and the high degree of homology shared by the different isoforms offer substantial challenges to discovering potential drugs. Medicinal and synthetic organic chemists have been continuously involved in developing CA inhibitors. This review explored the chemistry of different heterocycles as CA inhibitors using the last 11 years of published research work. It provides a pathway for young researchers to further explore the chemistry of a variety of synthetic as well as natural heterocycles as CA inhibitors.

New palladium complexes with N-heterocyclic carbene and morpholine ligands: Synthesis, characterization, crystal structure, molecular docking, and biological activities

This work includes the synthesis of a new series of palladium-based complexes containing both morpholine and N-heterocyclic carbene (NHC) ligands. The new complexes were characterized using NMR (1 H and 13 C), FTIR spectroscopic, and elemental analysis techniques. The crystal structure of complex 1b was obtained by utilizing the single-crystal X-ray diffraction method. X-ray studies show that the coordination environment of palladium atom is completed by the carbene carbon atom of the NHC ligand, the nitrogen atom of the morpholine ring, and a pair of bromide ligand, resulting in the formation of slightly distorted square planar geometry. All complexes were determined for some metabolic enzyme activities. Results indicated that all the synthetic complexes exhibited powerful inhibitory actions against all aims as compared to the control molecules. Ki values of new morpholine-liganded complexes bearing 4-hydroxyphenylethyl group 1a-e for hCA I, hCA II, AChE, BChE, and α-glycosidase enzymes were obtained in the ranges 0.93-2.14, 1.01-2.03, 4.58-10.27, 7.02-13.75, and 73.86-102.65 µM, respectively. Designing of reported complexes is impacted by molecular docking study, and interaction with the current enzymes also proclaimed that compounds 1e (-12.25 kcal/mol for AChE and -11.63 kcal/mol for BChE), 1c (-10.77 kcal/mol and -9.26 kcal/mol for α-Gly and hCA II, respectively), and 1a (-8.31 kcal/mol for hCA I) are showing binding affinity and interaction from the synthesized five novel complexes.

Investigation of 4-Hydrazinobenzoic Acid Derivatives for Their Antioxidant Activity: In Vitro Screening and DFT Study

Hydrazinobenzoic acid derivatives with isothiocyanate, benzylidene, and acid anhydride core units (1-13) were previously synthesized and fully characterized. Targets 1-13 were investigated for their antioxidant activities using different in vitro assays such as 1,1-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS), ferric reducing antioxidant power (FRAP), and reducing power capability. All derivatives showed antioxidant properties in relation to the standard butylated hydroxylanisole (BHA). Superior antioxidant activities was observed for compounds 3 and 5-9 at a concentration of 20 μg/mL (70-72%) when tested by the DPPH method in comparison to BHA (92%), and compounds 1-10 showed the highest free radical quenching activity (80-85%) when examined by ABTS at 20 μg/mL in relation to BHA (85%). Density function theory (DFT) studies were carried out using the B3LYP/6-311G(d,p) level of theory. Several antioxidant descriptors were calculated for targets 1-13 compared with BHA. Targets 1-13 were proposed to exhibit their antioxidant activities via the following three proposed antioxidant mechanisms: single electron transfer (SET), hydrogen atom transfer (HAT), and sequential proton loss electron transfer (SPLET). The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies and electron levels for 1-13 were also determined.