A study of the alkaloids ofVeratrum lobelianum
Conclusions1) At the beginning of vegetation, the total alkaloids in the epigeal part ofVeratrum lobelianum is 2.5% of the weight of the dry raw material, and at the end of vegetation, 0.036%.2) The new alkaloids veralosine, veralosinine, and veralosidine have been isolated from the epigeal part of the plant.3) On the basis of a study of chemical properties, IR, UV, NMR, and mass spectra, and also its conversion into tetrahydrosolasodine, structure and configuration I has been proposed as the most probable for veralosidine.
Solanum-alkaloide—XLVI : Synthese von solasodin
Abstract The steroidal alkaloid solasodine [(25R)]-22αN-spirosol-5-en-3β-ol, XIII] which was isolated from more than 60 species of the genus Solanum (Solanaceae) has been synthesized from (22S:25R)-22,26-imino-5α-cholestane-3β,16β-diol[tetrahydrosolasodine A, I]. The described transformation formally represents the total synthesis of solasodine, since the starting I is available from a simple pregnane derivative.
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.