Knoevenagel Condensation Catalyzed by DBU Brnsted Ionic Liquid without Solvent

A protocol for the Knoevenagel condensation of aromatic aldehydes with methylene compounds catalyzed by task specifed ionic liquid 1,8-diazabicyclo[5.4.0]-undec-7-en-8-ium lactate under solvent-free conditions has been developed. The reactions proceed at ambient temperature and the work-up procedures are very simple. Good to excellent yields could be obtained. The ionic liuid could be simply prepared and recycled efficiently.

Meso-Zeaxanthin:One of Important Carotenoids for Human Health

As one of optical isomers of zeaxanthin, meso-zeaxanthin is an important ingredient of macular pigment. Compared with lutein and zeaxanthin, meso-zeaxanthin may display strong functions as antioxidant and filtering short-wavelength, for example, the blue light. Comparisons among lutein, zeaxanthin and meso-zeaxanthin as well as functions and distributions together with the source of meso-zeaxanthin were discussed. The application as a supplement of diet and issues should be studied in the future for mesozeaxanthin were also analyzed.

Design, Synthesis and Inhibitory Properties against Coxsackie B3/B6 of Some Novel Triazole Derivatives

A series of 1,2,4-triazole derivatives were synthesized, and their abilities to inhibit the in vitro replication of Coxsackie B3/B6 were evaluated. Among the 1,2,4-triazole derivatives, compound 3 g displayed potent activity, with a high antiviral potency (IC50 = 1.71 μM (against CVB3), 1.43 μM (against CVB6)). The structures of all the new synthesized compounds were confirmed by 1H-NMR spectra, mass spectra and elemental analyses.

Synthesis of mono-substituted derivatives of 6-aminoquinoline

Several 6-aminoquinoline derivatives,which could be used in drug design,have been synthesized.The reaction conditions were comparatively studied,and the p-chloroaniline was used as optimum oxidant in Skraup-Doebner-Von Miller reaction.The nitro group was reduced effectively by SnCl2 with no halo-removed occurred.

Preparation and characterization of SO_(4)^(2−)−/TiO_(2)and S_(2)O_(8)^(2)−/TiO_(2) catalysts

Nanosized solid superacids SO_(4)^(2−)/TiO_(2)and S_(2)O_(8)^(2)−/TiO_(2),as well as MCM-41-supported SO_(4)^(2−)/ZrO_(2),were prepared.Their structures,acidities,and catalytic activities were investigated and compared using XRD,N2 adsorption-desorption,and in situ FTIR-pyridine adsorption,as well as an evaluation reaction with pseudoionone cyclization.The results showed that SO_(4)^(2−)/TiO_(2)and S_(2)O_(8)^(2)−/TiO_(2)possess not only nanosized particles with diameters<7.0 nm,a BET sur-face greater than 140 cm2/g and relatively regular mesostruc-tures with pores around 4.0 nm,but also a pure anatase phase and strong acidity.Different from the Lewis acid nature of SO_(4)^(2−)/ZrO_(2)/MCM-41,SO_(4)^(2−)/TiO_(2)and S_(2)O_(8)^(2)−/TiO_(2)exhibit mainly Brønsted acidities.The strongest Brønsted acid sites were produced on SO_(4)^(2−)/TiO_(2)promoted with H2SO4,while Lewis acid sites on S_(2)O_(8)^(2)−/TiO_(2)even stronger than those on SO_(4)^(2−)/ZrO_(2)/MCM-41 were generated when persulfate solu-tion was used as sulfating agent.Because of their distinct acid natures,SO_(4)^(2−)/TiO_(2)and S_(2)O_(8)^(2)−/TiO_(2)exhibited catalytic activities for the cyclization of pseudoionone that were much higher than that of SO_(4)^(2−)/ZrO_(2)/MCM-41.It can be concluded that the existence of more Brønsted acid sites was favorable for proton participation in the cyclization reaction.

A new isobenzofuranone derivative from a marine Streptomyces sp.

One new isobenzofuranone derivative, 1,4-dimethoxy-3-（3R＊-hydroxy-3R＊-methyl-1-tetralone）-1 （3H）-isobenzofuran （1）, was isolated from the broth of marine Streptomyces sp. M268. The structure was elucidated by spectroscopy characteristics as well as comparison with the literature. Compound 1 exhibited cytotoxicities against human cancer cell, HL-60, A549, and BEL-7402.