Paired Electrolysis-Enabled Arylation of Quinoxalin-2(1H)-ones.

The first paired electrolysis-enabled arylation of quinoxalin-2(1H)-ones was achieved using cyanoarenes as the arylation reagents. A variety of 3-arylquinoxalin-2(1H)-ones with various important functional groups were obtained in moderate to good yields under metal- and chemical oxidant-free conditions. With a pair of reductive and oxidative processes occurring among the substrates and reaction intermediates, the power consumption can be dramatically reduced.

Optimization of extraction technology of total saponins from Patrinia scabiosaefolia by response surface method and its contraction effect on isolated rat intestinal smooth muscle / 中草药

Objective: To optimize the extraction technology for total saponins from Patrinia scabiosaefolia (TSPS) by response surface method. At the same time, the function of promoting intestinal peristalsis by total saponins was investigated. Methods: UV spectrophotometric method was used to determine the contents of total saponins in P. scabiosaefolia at the wavelength of 510 nm by taking oleanolic acid as standard substance, and vanillin acetic acid as chromogenic reagent. The extraction rate of total saponins was used as index to evaluate the technology based on single factor test, in which three factors were considered the concentration of extraction solvent, solid-liquid ratio, extraction time, and their interaction on extraction were studied by response surface method. The contraction effect and signal changes of total saponins extract of P. scabiosaefolia on intestinal smooth muscle were recorded by tension transducer to the BL-420 biological experimental multi-channel physiological signal acquisition and processing system. Results: The best extraction conditions were as follows: ethanol concentration of 75% alcohol, solid-liquid ratio of 1:12, extraction time for 1.5 h, twice and extraction temperature of 90℃. The optimized extraction rate could reach 10.96 mg/g. P. scabiosaefolia extracts obtained using the optimized method showed significantly contraction effect on rat intestinal smooth muscle and the results were displayed as: colon > colon>jejunum>duodenum. The concentration at 0.32 mg/mL has the best effect of gastrointestinal contraction. Conclusion: The optimized extraction technology is stable and effective, and with higher extraction rate. The extract of P. scabiosaefolia has a significant promotion effect on intestinal smooth muscle of rat, which shows positive correlation with the rate of extract.