Annulation of a Methylenecyclopropane with Cyanoalkenes Catalyzed by Lewis Bases.

The annulation of a methylenecyclopropane with acyl cyanoalkenes by using DABCO or quinuclidine as a catalyst to give 2,3-dihydofurans has been developed. A stoichiometric amount of the Lewis bases promoted the isomerization of 2,3-dihydrofurans to furans. 1 H NMR spectra of the reaction in situ revealed that the methylenecyclopropane is opened by the Lewis base to form a reaction intermediate that is added to the cyanoalkenes.

Ginsenosides in Panax ginseng Extract Promote Anagen Transition by Suppressing BMP4 Expression and Promote Human Hair Growth by Stimulating Follicle-Cell Proliferation.

Studies showing that Panax ginseng promotes hair growth have largely been conducted using mice; there are few reports on how P. ginseng affects human hair growth. In particular, little is known about its effect on the telogen to anagen transition. To determine the effect of P. ginseng on human hair growth and the transition from the telogen to the anagen phase. The effects of P. ginseng extract (PGE) and the three major ginsenoside components, Rb1, Rg1, and Re, on the proliferation of human dermal papilla cells (DPCs) and human outer root sheath cells (ORSCs) were investigated. The effects of these compounds on the cell expression of bone morphogenetic protein 4 (BMP4), fibroblast growth factor 18 (FGF18) and Noggin were assessed by real-time PCR. The effect of PGE on hair-shaft elongation was determined in a human hair follicle organ-culture system. PGE and the three ginsenosides stimulated the proliferation of DPCs and ORSCs and suppressed BMP4 expression in DPCs but did not affect FGF18 expression in ORSCs and Noggin expression in DPCs. PGE stimulated hair-shaft growth. PGE and the ginsenosides Rb1, Rg1, and Re stimulate the transition from the telogen phase to anagen phase of the hair cycle by suppressing BMP4 expression in DPCs. These compounds might be useful for promoting the growth of human hair.

Enantioselective Reaction of N-Unprotected Activated Ketimines with Phosphine Oxides Catalyzed by Chiral Imidazoline-Phosphoric Acids.

The first enantioselective hydrophosphonylation of ketimines with phosphine oxides was developed. The reaction of unprotected ketimines with phosphine oxides using a bis(imidazoline)-phosphoric acid catalyst gave chiral α-quaternary aminophosphorous compounds having a primary amino group in excellent yields and enantioselectivities. Based on experimental results and DFT calculation, transition states were proposed to explain the stereoselectivity of the reaction.

Geotrichum candidum aldehyde dehydrogenase-inorganic nanocrystal with enhanced activity.

A novel Geotrichum candidum aldehyde dehydrogenase (GcALDH) effectively oxidized aldehydes to carboxylic acids under mild conditions. Nonetheless, the free form of GcALDH still had a limitation in stability and recyclability. Herein, to overcome these limitations, this study achieved the immobilization of the GcALDH by the organic-inorganic nanocrystal formation. The GcALDH nanocrystal exhibited 261 ± 40 % of activity comparing to the free enzyme. It also exhibited improved thermostability and recyclability as well as remained excellent substrate promiscuity, which suggested its potential use in green industries. To the best of our knowledge, this is the first time to report the ALDH-inorganic nanocrystal formation with superior properties.