1. Nanoparticles based on chitosan hydrochloride/hyaluronic acid/PEG containing curcumin: In vitro evaluation and pharmacokinetics in rats
Yurui Xu, Hongying Li, Sajid Asghar, Qinqing Shi, Wenwen Shi, Qineng Ping, Yanyu Xiao, Yibo Li, Liu Yang, Zhipeng Chen Int J Biol Macromol . 2017 Sep;102:1083-1091. doi: 10.1016/j.ijbiomac.2017.04.105.
Nanoparticles based on chitosan hydrochloride (CSH)-hyaluronic acid (HA)-PEG were prepared for delivering curcumin (CUR) (CUR-PNPs) to brain tumor. CUR-PNPs of 245.9nm and spherical morphology were obtained at optimized CSH/HA/PEG20000/CUR ratios with negative charge of about -27.2mV and EE of approximately 93.3%. Cytotoxicity studies showed that CUR-PNPs improved drug's anticancer activity in rat glioma cells (C6). The cellular uptake mechanism study showed active targeting of CUR-PNPs into C6 cells by HA mediated endocytosis. Clathrin-coated pit mediated endocytosis, clathrin-mediated endocytosis and macropincytosis were also identified as the entry pathways of PNPs into C6 cells. Pharmacokinetics of preparations in rats after i.v. administration further proved the superiority of CUR-PNPs (3.98 times greater than the area under the curve of CUR solution). In conclusion, CUR-PNPs might be a promising carrier for the therapy of brain tumors.
2. Metal-free and regiospecific synthesis of 3-arylindoles
Chuangchuang Xu, Jiaxi Xu, Wenlai Xie Org Biomol Chem . 2020 Apr 8;18(14):2661-2671. doi: 10.1039/d0ob00317d.
A convenient, metal-free, and organic acid-base promoted synthetic method to prepare 3-arylindoles from 3-aryloxirane-2-carbonitriles and arylhydrazine hydrochlorides has been developed. In the reaction, the organic acid catalyzes a tandem nucleophilic ring-opening reaction of aryloxiranecarbonitriles and arylhydrazine hydrochlorides and Fischer indolization. The organic base triethylamine plays a crucial role in the final elimination step in the Fischer indole synthesis, affording 3-arylindoles regiospecifically. The reaction features advantages of microwave acceleration, non-metal participation, short reaction time, organic acid-base co-catalysis, and broad substrate scope.
3. Iodine-Catalyzed Diazenylation with Arylhydrazine Hydrochlorides in Air
Ilesha Avasthi, Shashikant U Dighe, Sanjay Batra, Dinesh S Barak J Org Chem . 2018 Apr 6;83(7):3537-3546. doi: 10.1021/acs.joc.7b03149.
A mild approach to diazenylation of active methylene compounds and N-heterocyclic compounds with arylhydrazine hydrochlorides in the presence of iodine under basic aerobic conditions was developed. The reaction could be executed either under heating or in the presence of blue LED light, though the latter condition was found to be relatively efficient. Presumably, the aryldiazene produced by oxidation of arylhydrazine hydrochloride acts as a nitrogen scavenger of the radical intermediate generated from the active methylene compound in the presence of iodine to produce the diazo compounds. The scope and limitations of the protocol are presented.
