No abstract

A simple and effective extraction method based on solid-phase extraction (SPE) was developed to determine chlorothalonil, metalaxyl, triadimefon, dimetachlone, procymidone, flumetralin, oxadixyl and iprodione in Panax Notoginseng using gas chromatography-mass spectrometry with selected ion monitoring (GC/MS, SIM). The prepared samples were analysed with GC-MS in the selected ion monitoring mode (SIM) using one target and two or three qualitative ions for each analyte. In the method, hexane - dichloromethane（6:4，v/v）was selected to effectively extract the pesticides from the Panax Notoginseng samples. Solid-phase extraction was carried out using Supelclean ENVI-Carb/NH2 SPE Column with acetonitrile-toluene (3:1, v/v) as the eluted solvent. In the linear range of each pesticide, the correlation coefficient was R2≥0.99. The limit of detection ranged from 0.001 to 0.05 µg.mL-1, average recoveries ranged from 79.80% to 95.00%, with relative standard deviations between 1.96% and 4.32% for all 8 pesticides.They were readily achieved with this method for all tested pesticides.

The present study is the first investigation of the chemical composition and antimicrobial activitys of Marsdenia koi Tsiang essential oils. A total of forty-five compounds were identified, representing about 94.9% of the studied oil.The essential oil exhibited antibacterial activity against B.subtilis, S.aureus and S. albus with the MIC values of 50 μg/ml, 100μg/ml and 100μg/ml respectively.

BRAF, a serine/threonine specific protein kinase that is part of the MAPK pathway and acts as a downstream effector of RAS, is a potential therapeutic target in melanoma. We have studied a series of small-molecule BRAF inhibitors based on a 1H-imidazo[4,5-b]pyridine-2(3H)-one scaffold (ring A) as the hinge binding moiety and a number of substituted phenyl rings C that interact with the allosteric binding site. Based on molecular docking obtained by using GOLD, the interaction models on the receptor site of BRAF are guiding the design of potential inhibitory structures directed against BRAF activity.