1.An Iridium-Catalyzed Reductive Approach to Nitrones from N-Hydroxyamides.
Katahara S, Kobayashi S, Fujita K, Matsumoto T, Sato T, Chida N. J Am Chem Soc. 2016 Apr 13. [Epub ahead of print]
An iridium-catalyzed reductive formation of functionalized nitrones from N-hydroxyamides was reported. The reaction took place through two types of iridium-catalyzed reactions including dehy-drosilylation and hydrosilylation. The method showed high chemoselectivity in the presence of sensitive functional groups such as methyl esters, and was successfully applied to the synthesis of cyclic and macrocyclic nitrones, which are known to be challenging compounds to access in a regioselective manner by conventional methods. 1H NMR studies strongly supported generation of an N-siloxyamide and an N,O-acetel as the actual intermediates.
2.3-Dimensional ZnO/CdS nanocomposite with high mobility as an efficient electron transport layer for inverted polymer solar cells.
Wang Y1, Fu H1, Wang Y1, Tan L2, Chen L2, Chen Y2. Phys Chem Chem Phys. 2016 Apr 14. [Epub ahead of print]
The inclusions of solution-processed ZnO electron transport layers (ETLs) of inverted polymer solar cells can lead to various surface defects, which can act as interfacial recombination centers for photogenerated charges and thereby can lead to degradation of the device performance. Three-dimensional (3D) CdS with different morphologies, such as flower-like CdS (F-CdS), branched CdS (B-CdS), and spherical CdS (S-CdS), are synthesized to modify ZnO ETLs, by effectively removing the intragap states of the ZnO nanocrystal films by forming ZnO/F-CdS, ZnO/B-CdS, and ZnO/S-CdS composite ETLs, respectively. Moreover, ZnO/CdS possesses higher electron mobility and provides a larger interface between the ETL and active layer, which is beneficial for enhancing the power conversion efficiency (PCE) of the inverted organic solar cells. In particular, a device based on a ZnO/S-CdS ETL and thieno[3,4-b]-thiophene/benzodithiophene (PTB7):[6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) active layer achieved a PCE of 8.
3.AA-PMe, a novel asiatic acid derivative, induces apoptosis and suppresses proliferation, migration, and invasion of gastric cancer cells.
Jing Y1, Wang G1, Ge Y1, Xu M1, Tang S1, Gong Z2. Onco Targets Ther. 2016 Mar 17;9:1605-21. doi: 10.2147/OTT.S98849. eCollection 2016.
Asiatic acid (AA; 2α,3β,23-trihydroxyurs-12-ene-28-oic acid) is widely used for medicinal purposes in many Asian countries due to its various bioactivities. A series of AA derivatives has been synthesized in attempts to improve its therapeutic potencies. Herein we investigated the anti-tumor activities of N-(2α,3β,23-acetoxyurs-12-en-28-oyl)-l-proline methyl ester (AA-PMe), a novel AA derivative. AA-PMe exhibited a stronger anti-cancer activity than its parent compound AA. AA-PMe inhibited the proliferation of SGC7901 and HGC27 human gastric cancer cells in a dose-dependent manner but had no significant toxicity in human gastric mucosa epithelial cells (GES-1). AA-PMe induced cell cycle arrest in G0/G1 phase and blocked G1-S transition, which correlated well with marked decreases in levels of cyclin D1, cyclin-dependent kinase CKD4, and phosphorylated retinoblastoma protein, and increase in cyclin-dependent kinase inhibitor P15. Further, AA-PMe induced apoptosis of human gastric cancer cells by affecting Bcl-2, Bax, c-Myc, and caspase-3.
4.Direct vascular actions of quercetin in aorta from renal hypertensive rats.
Choi S1, Ryu KH2, Park SH2, Jun JY1, Shin BC3, Chung JH3, Yeum CH1. Kidney Res Clin Pract. 2016 Mar;35(1):15-21. doi: 10.1016/j.krcp.2015.12.003. Epub 2016 Jan 6.
BACKGROUND: Chronic treatment with the dietary flavonoid quercetin is known to lower blood pressure and restore endothelial dysfunction in animal models of hypertension. This study investigated the direct effects of quercetin on vascular response in chronic 2-kidney, 1-clip (2K1C) renal hypertensive rats. The effects of antioxidant vitamin ascorbic acid on the vasoreactivity were also examined.
