Chemical structure and fungicide selectivity
The influence of stereo- and other isomers, homologues and structural variations on the activity of various types of systemic fungicides is reviewed.
5-n-Butyl-2-dimethylamino-4-hydroxy-6-methylpyrimidine: a Systemic Fungicide
DURING a search for systemic fungicides it was found that 5-n-butyl-2-dimethylamino-4-hydroxy-6-niethylpyrimidine (I) gives exceptionally good control of powdery mildew (Sphaerotheca fuliginea (Schlecht)) on cucurbits, particularly when applied to the soil as a liquid or in granules. The compound has very low mammalian toxicity, with LD50 values (female rats) of 200–400 mg/kg (interperitoneal) and >4,000 mg/kg (oral).
Single step formation of biocompatible bimetallic alloy nanoparticles of gold and silver using isonicotinylhydrazide.
Manufacturing nanoparticles with controlled physicochemical properties using environment-friendly routes have potential to open new prospects for a variety of applications. Accordingly, several approaches have been established for manufacturing metal nanoparticles. Many of these approaches entail the use of hazardous chemicals and could be toxic to the environment, and cannot be used readily for biomedical applications. In the present work, we report a single step bio-friendly approach to formulate gold (Au), silver (Ag), and Au-Ag alloy nanoparticles with desired surface corona and composition using isonicotinylhydrazide (INH) as a reducing agent. INH also functioned as a stabilizing agent by enabling a surface corona around the nanoparticles. Remarkably, within a single step INH could also provide a handle in regulating the composition of Au and Ag in bimetallic systems without any additional chemical modification. The physicochemical and surface properties of the different nanoparticles thus obtained have been examined by analytical, spectroscopic and microscopic techniques. Cell cytotoxicity (release of lactate dehydrogenase), cell viability and intracellular reactive oxygen species (ROS) assays confirmed that the Au, Ag, and Au-Ag bimetallic nanoparticles prepared with INH are biocompatible. Finally, the presence of organic surface corona of INH on the nanoparticles was found to impart nanozyme activity and antimycobacterial sensitivity to the nanoparticles.