777020-72-1Relevant academic research and scientific papers
Selective Reduction of Azines to Benzyl Hydrazones with Sodium Borohydride Catalyzed by Mesoporous Silica-Supported Silver Nanoparticles: A Catalytic Route towards Pyrazole Synthesis
Charistoudi, Evangelia,Kallitsakis, Michael G.,Charisteidis, Ioannis,Triantafyllidis, Kostas S.,Lykakis, Ioannis N.
, p. 2949 - 2960 (2017)
The catalytic activity of supported silver nanoparticles on mesoporous silica was studied, for the selective reduction of azines into benzyl hydrazones using sodium borohydride as mild reducing agent. Different sizes of silver nanoparticles supported on mesoporous silica (Ag/HMS) were successfully prepared by two methods, i.e., wet impregnation followed by reduction with hydrogen at 350 °C and in situ deposition/reduction with a mixture of amines (ethanolamine and ethylenediamine). The Ag/HMS (amines) catalyst was found to promote the selective 1,2-reduction of aryl-substituted azines, compared to the corresponding 1,4-reduction that occurs in general reduction processes. This catalytic transfer hydrogenation process found to be clean, fast and quantitative (>99% yields and selectivity) towards benzyl hydrazone synthesis under mild conditions. Of great importance is that under the present catalytic conditions reducible functional groups remain intact. Formal kinetics, support the in situ formation of silver hydride species being responsible for the reduction process. The presence of protic polar methanol enhanced the catalytic activity of Ag/HMS. Based on the recycling studies the catalytic system Ag/HMS-NaBH4 was found to catalyze the selective reduction of azines nine times without significant loss of its activity. Finally, a one-pot reaction between the in situ produced benzyl hydrazones and a series of nitrostyrenes readily provided the regioselective synthesis of 1,3,5-subtituted pyrazoles, highlighting a useful synthetic application of the catalytic protocol. (Figure presented.).
Targeting fungal virulence factor by small molecules: Structure-based discovery of novel secreted aspartic protease 2 (SAP2) inhibitors
Dong, Guoqiang,Han, Guiyan,Li, Chenglan,Liu, Na,Liu, Yang,Sheng, Chunquan,Tu, Jie,Wu, Shanchao
supporting information, (2020/07/06)
Secreted aspartic protease 2 (SAP2), a kind of virulence factor, is an emerging new antifungal target. Using docking-based virtual screening and structure-based inhibitor design, a series of novel SAP2 inhibitors were successfully identified. Among them, indolone derivative 24a showed potent SAP2 inhibitory activity (IC50 = 0.92 μM). It blocked fungi biofilm and hypha formation by down-regulating the expression of genes SAP2, ECE1, ALS3 and EFG1. As a virulence factor inhibitor, compound 24a was inactive in vitro and showed potent in vivo efficacy in a murine model of invasive candidiasis. It represents a promising lead compound for the discovery of novel antifungal agents.
