Synthesis and Characterization of Glutamic-Chitosan Hydrogel for Copper and Nickel Removal from Wastewater.

Chitosan was reacted with four concentrations (2.5, 5, 10 and 20 mmol) of glutamic acid resulting in four types of glutamic-chitosan hydrogels (GCs), the activity of the resulted compounds on the removal of copper(II) and nickel(II) from wastewater were tested. The results indicated that by increasing glutamic acid concentration from GCs-1 to GCs-4, the efficiency of removing Cu(II) and Ni(II) were decreased, which may be due to a decrease in the pore size of the hydrogels as a result of the increased degree of crosslinking.

Exploring new selective 3-benzylquinoxaline-based MAO-A inhibitors: design, synthesis, biological evaluation and docking studies.

In this investigation, we searched for novel MAO-A inhibitors using a 3-benzylquinoxaline scaffold based on our earlier findings. Series of N'-(3-benzylquinoxalin-2-yl)acetohydrazide, 4a, N'-(3-benzylquinoxalin-2-yl)benzohydrazide derivatives 4b-f, N'-[2-(3-benzyl-2-oxoquinoxalin-1(2H)-yl)acetyl]benzohydrazide derivatives 7a-d, (9H-fluoren-9-yl)methyl 1-[2-(2-(3-benzyl-2-oxoquinoxalin-1(2H)-yl)acetyl)-hydrazinyl]-2-ylcarbamate derivatives 8a-c, 2-(3-benzyl-2-oxoquinoxalin-1(2H)-yl)-N'-benzylidene acetohydrazide derivatives 9a-h, and ethyl 2-(3-benzyl-2-oxoquinoxalin-1(2H)-yl)acetate derivatives 10a-e were synthesized and evaluated in vitro as inhibitors of the two monoamine oxidase isoforms, MAO-A and MAO-B. Most of the compounds showed a selective MAO-A inhibitory activity in the nanomolar or low micromolar range.

Antioxidant and antitumor activities of new synthesized aromatic C-nucleoside derivatives.

The carbohydrazide 1 was used as the precursor for the synthesis of a number of new aromatic C-nucleosides containing 1,3,4-oxadiazole 7, [1,3,4]oxadiazolo[2,3-a]isoindole 10b and pyrazole units 18. On the other hand, the thiosemicarbazone 20 was used as the key intermediate for synthesis of 1,3,4-oxadiazole  and 1,2,4-triazole-3-thione derivatives 21 and 23. The antioxidant activities of the prepared compounds were evaluated.

Synthesis and bioassay of a new class of furanyl-1,3,4-oxadiazole derivatives.

Tyrosinase enzyme is a monophenol monoxygenase enzyme, which plays an important role in human as a rate limiting step enzyme for different specific metabolic pathways, as well as its useful application in industry and agriculture. So this study was carried out to test the effect of newly prepared compounds containing 1,3,4-oxadiazoles with different substituted groups on tyrosinase enzyme activity, hoping to use them in the treatment of some diseases arising from tyrosinase activity disorders such as Parkinson's disease, schizophrenia, autism, attention deficit, hyperactivity disorder, and cancer.

Synthesis, antibacterial and antifungal activity of some new pyrazoline and pyrazole derivatives.

A series of 2-pyrazolines 5-9 have been synthesized from α,β-unsaturated ketones 2-4. New 2-pyrazoline derivatives 13-15 bearing benzenesulfonamide moieties were then synthesized by condensing the appropriate chalcones 2-4 with 4-hydrazinyl benzenesulfonamide hydrochloride. Ethyl [1,2,4] triazolo[3,4-c][1,2,4]triazino[5,6-b]-5H-indole-5-ethanoate (26) and 1-(5H-[1,2,4]triazino[5,6-b] indol-3-yl)-3-methyl-1H-pyrazol-5(4H)-one (32) were synthesized from 3-hydrazinyl-5H-[1,2,4]triazino[5,6-b]indole (24).

Synthesis of new 1,3,4-thiadiazole and 1,2,3,4-oxathiadiazole derivatives from carbohydrate precursors and study of their effect on tyrosinase enzyme.

5-(1,2,3,4-Tetrahydroxybutyl)-2-methylfuran-3-carbohydrazide (2) was condensed with a variety of ketones to afford carbohydrazide derivatives 3-6. Acetylation of 3-5 afforded the acetyl derivatives 7-9, while periodate oxidation of 3-6 afforded the formyl derivatives 10-13. Acid catalyzed condensation of thiosemicarbazide or o-tolylthiosemicarbazide with the prepared aldehydes 10-12 gave thiosemicarbazone derivatives 14-19.

5-(5-Aryl-1,3,4-oxadiazole-2-carbonyl)furan-3-carboxylate and new cyclic C-glycoside analogues from carbohydrate precursors with MAO-B, antimicrobial and antifungal activities.

Cyclization of acyclic C-glycoside derivatives 1a,b to 2a,b as the major isomers, and 4a,b as the minor isomers were carried out. The isopropylidene derivatives 3a,b were prepared, as well as the hydrazide derivative 6, which was condensed with a variety of aldehydes to give hydrazones 7a-e which were also prepared from the compounds 12a-e. Acetylation of 7a,d gave the corresponding acetyl derivatives 8a,d, respectively.

A regio- and stereo-controlled approach to triazoloquinoxalinyl C-nucleosides.

The synthesis of a new series of acyclic triazoloquinoxalinyl C-nucleosides and their transformation to their cyclic analogs are described following protection, activation, and deprotection with subsequent intramolecular nucleophilic substitution protocol. The antibacterial potency of the new compounds was determined using an inhibition zone diameter test. The results show that 3a and 2b exhibit good activity against Escherichiacoli and Candidaalbicans.

Synthesis of new series of quinoxaline based MAO-inhibitors and docking studies.

A series of 2-benzyl-3-(2-arylidenehydrazinyl)quinoxalines 3, 4-benzyl-1-aryl-[1,2,4]triazolo[4,3-a]quinoxalines 4 and phenyl(1-aryl-[1,2,4]triazolo[4,3-a]quinoxalin-4-yl)methanones 5 analogues were synthesized and investigated for their monoamine oxidase (MAO) inhibitory property. The inhibition profile was found to be competitive for compounds 3k, 3m, 5f and 5n with MAO-A selectivity. Observation of the docked positions of these compounds revealed interactions with many residues previously reported to have an effect on the inhibition of the enzyme.

Synthesis of 3-benzyl-2-substituted quinoxalines as novel monoamine oxidase A inhibitors.

A new series of 3-benzyl-2-substituted quinoxalines have been synthesized by means of microwave enhancement of nucleophilic substitution reaction involving the corresponding 2-chloroquinoxaline analogs and substituted amines or hydrazine. The synthesized compounds were evaluated for their monoamine oxidase A and B inhibitory activity by determination of their IC(50). All the newly synthesized compounds showed more selective inhibitory activity toward MAO-A than MAO-B.