Synthesis, characterization, crystal structure, electrochemical studies and biological evaluation of metal complexes with thiosemicarbazone of glyoxylic acid

Cobalt and nickel nitrates form with thiosemicarbazone of glyoxylic acid (H(2)GAT) complexes of empirical composition Co(C3H4N3O2S)(2)center dot 2H(2)O, Ni(C3H4N3O2S)(2)center dot 2H(2)O and Ni(C3H6N3O2S)(2). X-ray diffraction studies have shown that the Co(HGAT)(2)center dot 2H(2)O, Ni(HGAT)(2)center dot 2H(2)O complexes are mononuclear, in which the coordination around the metal is octahedral, made up of two sulfur atoms, two nitrogen atoms and two oxygen atoms from two ligands. By the interaction of NiCl2 center dot H2O with 2-[2-(aminothioxomethyl)hydrazinyl] acetic acid (H(2)TAA) instead of the expected the metal thiosemicarbazonate complex with the hydrogenated on the azomethine group ligand was obtained. The redox properties of these compounds were also investigated by voltammetry on Pt in dimethylsulfoxide/tetrabutylammonium perchlorate. These thiosemicarbazone of glyoxylic acid derivatives had effective inhibition against alpha-glycosidase, cytosolic carbonic anhydrase I and II isoenzymes, butyrylcholinesterase and acetylcholinesterase. K-i values were found as 26.12-36.58 nM for hCA I, 20.73-40.78 nM for hCA II, 184.30-642.18 nM for AChE, 123.67-342.37 nM for BChE, and 14.66-45.62 nM for alpha-glycosidase. (C) 2018 Elsevier Ltd. All rights reserved

Enzyme inhibitory function and phytochemical profile of Inula discoidea using in vitro and in silico methods

Many plant species have a large diversity of secondary metabolites with different biological activities. This study aims to assess the phenolic constituent, enzyme inhibitory and antioxidant activities of the aqueous (water) and methanol extracts of Inula discoidea. The enzyme assays showed effective enzyme inhibition of the methanol extract against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), glutathione S-transferase (GST), and α-glycosidase (α-Gly) enzymes. The IC50 values for AChE, BChE, GST, and α-Gly were found as 38.5 mg/mL, 34.65 mg/mL, 77.0 mg/mL, and 40.76 mg/mL, respectively. Antioxidant properties of the aqueous and methanol extracts of I. discoidea were determined by four well-known in vitro techniques (ABTS, CUPRAC, DPPH, and FRAP methods). The antioxidant values of both water and methanol extracts were found to be better than the standard antioxidants (BHA, BHT, ascorbic acid, and α-tocopherol) in ABTS and CUPRAC methods. According to an updated LC-MS/MS technique analysis, quinic acid (21.08 mg/g), protocatechuic acid (4.49 mg/g), and gallic acid (0.48 mg/g) were found as major phenolic compounds of the plant extract. The binding interactions of major phenolic compounds of I. discoidea with the AChE, BChE, GST, and α-Gly enzymes were investigated by the molecular docking studies

Synthesis, spectroscopic properties, crystal structures, antioxidant activities and enzyme inhibition determination of Co(II) and Fe(II) complexes of Schiff base

Considering the importance of metal complexes in the development of medical science, two different Schiff base Fe(II) and Co(II) metal complex compounds were synthesized with Schiff base obtained through the condensation of 1-(4-aminophenyl)ethanone with 2-hydroxy-3-methoxybenzaldehyde. The reactions of the ligand with Co(II) and Fe(II) metal ions enabled six coordination compounds with octahedral geometries. The novel metal complexes were characterized by IR, elemental analyses, magnetic susceptibility, mass spectra, UV-Vis, thermogravimetry-differential thermal analysis (TGA-DTA) and X-ray diffraction analysis. The antioxidant properties of the new compounds were investigated using different in vitro assays. Moreover, enzyme inhibition of derivatives complexes against carbonic anhydrase I and II isoenzymes (CA I and II) and acetylcholinesterase (AChE) was evaluated. The best inhibitor complex for CA I and II isoenzymes was the Fe(II) complex with K-i values of 52.83 +/- 11.52 and 63.34 +/- 8.88, respectively

Sage (Salvia pilifera): determination of its polyphenol contents, anticholinergic, antidiabetic and antioxidant activities

In this work, we determined for the first time the Salvia pilifera Montbret & Aucher ex Bentham as an important source for natural products with antioxidant and antidiabetic potentials. In this context, methanol (MESP) and water (WESP) extracts were prepared from aerial parts of S. pilifera. Also, it was evaluated for antioxidant profile by eight distinguishes bioanalytical methods and inhibition effects against enzymes linked to different diseases, namely butyrylcholinesterase (BChE), acetylcholinesterase (AChE), ?-glycosidase and ?-amylase. Also, the polyphenolic compositions of MESP and WESP were evaluated by high performance liquid chromatography and tandem mass spectrometry (LC–MS/MS). Fourteen phenolics were identified in the evaporated MESP and thirteen phenolic compounds were identified in the lyophilized WESP. Also, we performed the antioxidant properties of both extracts. In order to estimate the capacity of MESP and WESP to act as antioxidants, 1,1-diphenyl-2-picryl-hydrazyl radicals (DPPH·), 2,2´-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radicals (ABTS·+) and N,N-dimethyl-p-phenylenediamine radicals (DMPD·+), scavenging activities, ferric ions (Fe3+), Fe3+-TPTZ and cupric ions (Cu2+) reducing assays were studied. MESP and WESP were found as potent effective DPPH· (IC50: 7.05 and 8.56 µg/mL), ABTS·+ (IC50: 3.52 and 4.76 µg/mL) and DMPD·+ (IC50: 28.92 and 30.95 µg/mL) scavenging effects. On the other hand, MESP and WESP showed the potent inhibition effects against AChE (IC50: 94.93 and 138.61 µg/mL), BChE (IC50: 60.05 and 99.13 µg/mL), ?-glycosidase (IC50: 23.28 and 36.47 µg/mL) and ?-amylase (IC50: 46.21 and 97.67 µg/mL) enzymes. This study will be an innovative and guider for further studies for antioxidant properties for industrial or medicinal plants. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.King Saud University, KSUS.A. would like to extend his sincere appreciation to the Distinguished Scientist Fellowship Program at King Saud University for funding this research