No abstract

A variety of 2,3-bifunctionalized quinoxalines (6-14) have been prepared by the condensation of 1,6-disubstituted-hexan-1,3,4,6-tetraones (1-4) with o-phenylenediamine, (R,R)-1,2-diaminocyclohexane and p-nitro-o-phenylenediamine. It is concluded that strong intramolecular N-H----O bonds in the favoured keto-enamine form may be responsible for the minimal biological activities observed in DNA footprinting, anti-tubercular, anti-fungal and anticancer tests with these hyper π-conjugated quinoxaline derivatives. However, subtle alteration by addition of a nitro group affecting the charge distribution confers significant improvements in biological effects and binding to DNA.

Fourteen native date cultivars from different oases and regions of Morocco, Tunisia and Algeria were examined for their approximate composition, water activity, and CIELAB parameters. Sugars were the predominant component in all studied date cultivars (~ 54.14 -75.56 g/100g dry matter), followed by moisture content (~7.2 -31.9%), along with small amount of protein (~1.9 -3.3g/100g dry matter), fat (~ 0.1 -0.44g/100g dry matter), and ash (~1.88 -3.45g/100 g dry matter). Dates with early maturity had the highest water activity (0.78 -0.87) in contrast to late maturing dates cultivars. In the Deglet Nour (Tunisia) and Aziza bouzid (Morocco) cultivars, sucrose is dominant, whereas, the majority of other cultivars were rich in fructose and glucose in comparable proportions. No significant changes were observed in the approximate composition of samples of different geographical origins. All cultivars show significant differences in color. The date with late maturity (from Assiane, Aziza bouzid and Boufeggous gharas locations of Morocco) were characterized by higher L * , a * , b * than the other date cultivars. Chemical composition of dates seems to be a good tool for fruit physiological and technological ability studies.

Background This work aims to study the optimal conditions of the fermentation culture medium used for the production of extracellular enzymes (amylase, cellulase, lipase, and protease) from previously isolated Aspergillus niger strains in date by-products. Results The five most powerful isolates selected based on the zone of degradation formed on Petri plates by the substrate were subjected to the quantitative evaluation of their enzymatic production. All five strains showed almost similar API-ZYM profiles, with minor variations observed at the level of some specific enzyme expression. The production of cellulase and amylase was depending on pH and incubation temperatures. ASP2 strain demonstrated the high production rate of amylase (at pH 5 and 30 °C) and cellulase (at pH 6 and 30 °C) for 96 h of incubation. Conclusion The A. niger showed the ability to produce several extracellular enzymes and can be used in the valorization of different agroindustrial residues.

Twelve new Schiff base derivatives have been prepared by the condensation reaction of different amino substituted compounds (aniline, pyridin-2-amine, o-toluidine, 2-nitrobenzenamine, 4-aminophenol, and 3-aminopropanol) and substituted aldehydes such as nicotinaldehyde, o,m,p-nitrobenzaldehyde, and picolinaldehyde in ethanol using acetic acid as a catalyst. The envisaged structures of the all the synthesized ligands have been confirmed on the basis of their spectral analysis FT-IR, mass spectroscopy, 1H- and 13C-NMR. In vitro screening of their antibacterial and antifungal potential against Escherichia coli bacterium and Fusarium oxysporum f.sp albedinis (F.o.a) fungus, respectively, revealed that all the ligands showed no significant antibacterial activity, whereas most of them displayed good antifungal activity. Homology modeling and docking analysis were performed to explain the antifungal effect of the most and least active compound against two F.o.a fungus proteins.