RESUMO
A series of 1,2,4-triazolo-quinazolinones and 1,2-benzisothiazolone derivatives (S1-S12) were successfully synthesized as environmentally friendly alternatives to copper-based antifouling paints using N-alkylation, cyclocondensation, and one-pot three-component and amide coupling reactions. The monoclinic structure of single-crystal 1,2,4-triazolo-quinazolin-acetic acid (S8) was confirmed by single-crystal X-ray diffraction analysis. All the synthesized molecules were studied for their in silico molecular docking interactions with three target proteins, namely, RbmA, ToxR, and Bap. Following that, the antialgal activity was assessed against two types of marine algae: Chlorella sp. and Chaetoceros curvisetus. The minimal inhibitory concentration and zone of inhibition have been used to evaluate the antibacterial activities of S1-S12 against both marine Gram-positive (Staphylococcus aureus) and Gram-negative (Vibrio parahemolyticus and Vibrio vulnificus) bacteria. Additionally, antifouling studies have been done on all the compounds, and among them, 1,2,4-triazolo-quinazolinyl-acetate (S7), 1,2,4-triazolo-quinazolinyl-acetic acid (S8), 1,2,4-triazolo-quinazolinyl-oxobutanoate (S9), benzo[d]isothiazolyl butanoate (S10), benzo[d]isothiazolyl-acetic acid (S11), and 1,2,4-triazolo-quinazolinyl-acetyl-benzo[d]isothiazolone (S12) exhibited good antialgal, antibacterial, and antifouling activities.
RESUMO
NADPH is an important cofactor in the cell. In addition to its role in the biosynthesis of critical metabolites, it plays crucial roles in the regeneration of the reduced forms of glutathione, thioredoxins and peroxiredoxins. The enzymes and pathways that regulate NADPH are thus extremely important to understand, and yet are only partially understood. We have been interested in understanding how NADPH fluxes are altered in the cell. We describe here both an assay and a genetic screen that allows one to discern changes in NADPH levels. The screen exploits the secondary redox property of NADPH. At low levels of glutathione we show that the redox contributions of NADPH become critical for growth, and we have used this to develop a genetic screen for genes affecting NADPH homeostasis. The screen was validated in pathways that both directly (pentose phosphate pathway) and indirectly (glycolytic pathway) affect NADPH levels, and was then exploited to identify mitochondrial genes that affect NADPH homeostasis. A total of 239 mitochondrial gene knockouts were assayed using this screen. Among these, several genes were predicted to play a role in NADPH homeostasis. This included several new genes of unknown function, and others of poorly defined function. We examined two of these genes, FMP40 which encodes a protein required during oxidative stress and GOR1, glyoxylate reductase. Our studies throw new light on these proteins that appear to be major consumers of NADPH in the cell. The genetic screen is thus predicted to be an exceedingly useful tool for investigating NADPH homeostasis.
