Reactions of 3-(1-arylhydrazono-L-threo-2,3,4-trihydroxybutyl)-1-methyl-2-Quinoxalinones

The 1-methyl derivatives (3 and 4) of 3-(1-phenyl- (1) and 3-(1-p-bromophenylhydrazono-L-threo-2,3,4-trihydroxybutyl)-2-quinoxalinone (2) were prepared by methylation. Periodate oxidation of 3 gave 1-methyl-3-[1-(phenylhydrazono)glyoxal-1-yl]-2-quinoxalinone (5), which, on reduction with sodium borohydride, gave the corresponding 3-[2-hydroxy-1-(phenylhydrazono)ethyl] derivative (8). Reaction of 5 with hydroxylamine or benzoylhydrazine gave the corresponding 2-oxime (6) and 2-(benzoylhydrazone) (7), respectively. Acetic anhydride causes one molecule of 3 or 4 to undergo elimination of two molecules of water, with simultaneous acetylation and ring closure to afford pyrazoles 9 and 10, respectively. Pyrolysis of the triacetate of 3 led to the elimination of acetic acid from the sugar and the hydrazone residue, to give the 3-[5-(acetoxymethyl)-1-phenylpyrazol-3-yl] derivatives (9). Acetic acid was found to effect the same rearrangement, but without acetylation, of 1, 2, and 3 to give the 3-[5-(hydroxymethyl)] derivatives 11, 12, and 13, respectively. The structure of these pyrazoles was confirmed by a series of reactions, including methylation and acetylation. The n.m.r. and i.r. spectra of the compounds were investigated.     

Purification and Characterization of DT 389 GCSF Fusion Protein: A Unique Immunotoxin Against the Human Granulocyte-Colony Stimulating Factor Receptor

Immunotoxin is a recombinant fusion toxin which has been developed to kill cancer cells selectively. DT389GCSF as a new immunotoxin consists of a truncated     

Expression of Enterocin-P in HEK Platform: Evaluation of Its Cytotoxic Effects on Cancer Cell Lines and Its Potency to Interact with Cell-Surface Glycosaminoglycan by Molecular Modeling

International Journal of Peptide Research and Therapeutics - Cancer remains one of the leading causes of death worldwide. Introduction of natural compounds with anticancer properties can be an...     

Nesfatin-1 Ameliorate Learning and Memory Deficit via Inhibiting Apoptosis and Neuroinflammation Following Ethanol-Induced Neurotoxicity in Early Postnatal Rats

International Journal of Peptide Research and Therapeutics - Fetal exposure to alcohol can cause a wide range of long-lasting physiological and behavioral effects, collectively referred to as fetal...     

Exploring Lassa Virus Proteome to Design a Multi-epitope Vaccine Through Immunoinformatics and Immune Simulation Analyses

International Journal of Peptide Research and Therapeutics - Lassa virus (LASV) is responsible for a type of acute viral haemorrhagic fever referred to as Lassa fever. Lack of adequate treatment...     

A Series of Benzylidenes Linked to Hydrazine‐1‐carbothioamide as Tyrosinase Inhibitors: Synthesis,Biological Evaluation and Structure−Activity Relationship

Tyrosinase is a type 3 copper enzyme responsible for skin pigmentation disorders, skin cancer, and enzymatic browning of vegetables and fruits. In the present article, 12 small molecules of 2‐benzylidenehydrazine‐1‐carbothioamide were designed, synthesized and evaluated for their anti‐tyrosinase activities followed by molecular docking and pharmacophore‐based screening. Among synthesized thiosemicarbazone derivatives, one compound, (2E)‐2‐[(4‐nitrophenyl)methylidene]hydrazine‐1‐carbothioamide, is the strongest inhibitor of mushroom tyrosinase with IC₅₀ of 0.05 μM which demonstrated a 128‐fold increase in potency compared to the positive control. Kinetic studies also revealed mix type inhibition by this compound. Docking studies confirmed the complete fitting of the synthesized compounds into the tyrosinase active site. The results underline the potential of 2‐benzylidenehydrazine‐1‐carbothioamides as potent pharmacophore to extend the tyrosinase inhibition in drug discovery.