Protective effects of cyclodextrins on edaravone degradation induced by atmospheric oxygen or additive oxidant

Journal of Inclusion Phenomena and Macrocyclic Chemistry - Antioxidants scavenge free radicals and may help prevent disease. However, due to poor stability, continuous intake is required. This...     

Revised structure of kasarin, an antibacterial pyrazinone compound from the marine microorganism Hyphomycetes sp.

Kasarin is an antibacterial marine alkaloid that was isolated from the microorganism Hyphomycetes sp. Its structure was previously reported to be an azetinone compound 1. However, detailed spectroscopic analysis of the natural compound and its related synthetic analogs revealed that the structure of kasarin should be revised to be a novel 5-malonyloxy-1-methoxy-pyrazin-2(1H)-one derivative 2.     

Facile and efficient synthesis of lactols by a domino reaction of 2,3-epoxy alcohols with a hypervalent iodine(III) reagent and its application to the synthesis of lactones and the asymmetric synthesis of (+)-tanikolide

The domino reaction of 2,3-epoxy-1-alcohol derivatives, namely tetrasubstituted 2,3-epoxy-1-alcohols and 2- or 3-alkyl trisubstituted 2,3-epoxy-1-alcohols, with PhI(OCOCF(3))(2) in the presence of H(2)O is described in detail. In this reaction, several types of lactol derivatives can be directly obtained from the 2,3-epoxy-1-alcohol derivatives in a single operation. The obtained lactols were successively converted into the corresponding lactones. This reaction is applicable to the construction of optically active lactone compounds. The asymmetric total synthesis of (+)-tanikolide, an antifungal marine natural product, has been effectively achieved by using this reaction.     

Convenient synthesis of photoaffinity probes and evaluation of their labeling abilities

Convenient synthesis of a variety of photoaffinity probes was accomplished by utilizing our Ns strategy and novel resin. The synthetic probes were evaluated via the labeling ability with the preseniline 1 C-terminal fragments, which was identified as a therapeutic target for Alzheimer's disease.     

Versatile direct dehydrative approach for diaryliodonium(III) salts in fluoroalcohol media

We have found that the use of fluoroalcohol media greatly enhanced the efficiency and scope of the direct dehydrative condensation of arenes and hypervalent iodine(III) compounds; the present clean method has a broad range of applicability as well as unique selectivity in the aromatic substrates, and is highly efficient even in polymer functionalization.     

3+2] coupling of quinone monoacetals by combined acid-hydrogen bond donor

The expeditious and efficient [3+2] coupling approach of quinone monoacetals 1 with alkene nucleophiles 2 by the action of an activated Br?nsted acid in the presence of a hydrogen bond donor perfluorinated alcohol has been achieved. With the optimized combined acid, the reaction could proceed under mild conditions by only mixing the two reactants to afford the cycloadducts 3 in a short time (within 10 min) with good to quantitative yields.     

Extraction of amphetamines and methylenedioxyamphetamines from urine using a monolithic silica disk-packed spin column and high-performance liquid chromatography-diode array detection

To overcome the limitations of solid-phase extraction, we developed a device comprising a spin column packed with octadecyl silane-bonded monolithic silica for extracting amphetamines and methylenedioxyamphetamines from urine. Urine (0.5mL), buffer (0.4mL), and methoxyphenamine (internal standard) were directly put into the preactivated column. The column was centrifuged (3000rpm, 5min) for sample loading and washed. The adsorbed analytes were eluted and analyzed by high-performance liquid chromatography, without evaporation. The results were as follows: linear curves (drug concentrations of 0.2-20microg/mL); correlation coefficients >0.99; detection limit, 0.1microg/mL. The proposed method is not only useful for drugs from biological materials but also highly reproducible for the analysis of these drugs in urine.     

Long-alkyl-chain quaternary ammonium lactate based ionic liquids

A new group of quaternary ammonium lactate based ionic liquids have been prepared and characterized. Didecyldimethylammonium (DDA) and benzalkonium (BA) D,L- and L-lactates are air-stable, hydrophilic, surface-active salts. They are very effective antibacterial and antifungal agents, especially the DDA lactates, against Streptococcus mutants and Candida albicans. Their activities are comparable or more effective than the original benzalkonium chloride. In addition, they have been shown to be good insect-feeding deterrents. However, they are poor antifungal agents for wood preservation. The toxicity of the DDA and BA lactates has also been studied and the results are presented in this paper.