ABSTRACT
@#In this paper,a new method for catalytic synthesis of chalcones from substituted acetophenone and substituted benzaldehyde in polyphosphoric acid/concentrated sulfuric acid system was proposed,and the reaction conditions were optimized. The results showed that the optimized reaction conditions were determined as polyphosphoric acid of 5 equiv. and concentrated sulfuric acid of 20 equiv.,with 1,4-dioxane as solvent at 90 °C for 2 h under nitrogen protection. Twelve chalcones were synthesized with good yield. All target compounds were characterized by IR,HRMS,1H NMR and 13C NMR.
ABSTRACT
Penthorum chinense is widely distributed in eastern Asia. It has various efficacies with excellent pharmaceutical and edible prospects. It contains various types of chemical components, and main components are flavonoids, lignans, coumarins, acetophenones, tannins, triterpenes, organic acids, esters, and volatile oils. This article classifies and summarizes the chemical constituents and hopefully provides a reference for further research, development and utilization of P. chinense.
ABSTRACT
In order to isolate and purify the reference compounds and improve the quality standard of ethnic medicine of Radix of Cynanchum otophyllum, the ethanol extracts were isolated by column chromatography onsilica gel, C₁₈ reverse-phase silica gel, and semi-preparative HPLC. Twelve compounds were isolated and their structures were elucidated as 2,4-dihydroxy-6-methoxyphenylethanone(1), 4,6-dihydroxy-2-methoxyphenylethanone(2), p-hydroxyacetophenone(3), baishouwubenzophenone(4), 2,4-dihydroxyacetophenone(5), 2,5-dihydroxyacetophenone(6), otophylloside A(7),otophylloside B(8), caudatin-3-O-β-D-cymaropyranosyl-(1→4)-β-D-digitoxopyranoside(9),caudatin-3-O-β-D-glucopyranosyl-(1→4)-β-D-oleandropyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-digitoxopyranoside(10),qingyangshengenin-3-O-β-D-oleandropyranosyl-(1→4)-β-D-cymaropyranoside(11),caudatin-3-O-β-D-oleandropyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-cymaropyranoside(12) on the basis of spectral analysis. Compounds 1 and 2 were isolated from the genus Cynanchum for the first time, and compounds 3-4, 9-12 were obtained from this plant for the first time.These compounds are main active components of Radix of C.otophyllum and can be used as reference substances for the quality control of this ethnic medicine.
ABSTRACT
Twelve new chalcones were synthesized by claisen-schmidid condensation and studies for their toxicity to fish. Some of the chalcones have exhibited moderate activity. The structures of synthetic compounds have been characterized by analytical and spectral data.
ABSTRACT
AIM To study in vitro stereoselective metabolism of mandelic acid (MA) in 3 kinds of laboratory animal tissue fractions and observe the differences of MA biotransformation. METHODS MA enantiomers were incubated with the tissue fractions from rats, mice and rabbits. The phenylglyoxylic acid (PGA) concentrations in incubation mixture were determined by high-performance liquid chromatography. Coenzymes and inhibitors were co-incubated with MA to investigate their effects on MA metabolism. RESULTS Only S-MA showed a unique metabolism in liver and kidneys S9 fractions of rats. No inhibition of the enzyme activity was observed by addition of ethanol or 4-methyl pyrazole. NADPH caused a remarkable increase in S-MA metabolism. CONCLUSION Nonmicrosomal enzymes in kidneys and liver except alcohol dehydrogenase are responsible for the stereoselective metabolism of MA in rats. The MA biotransformation is significantly different between rats and mice or rabbits.