Simultaneous enantioseparation of citrus flavonoids in chiral microemulsion electrokinetic chromatography using deep eutectic solvents.

A novel, deep eutectic solvent (DES)-assisted sodium cholate (SC)-chiral microemulsion electrokinetic chromatography method is presented for separation of five flavonoid glycoside enantiomers, namely hesperidin, naringin, narirutin, eriocitrin, and neoeriocitrin. Herein, we develop a novel, green DES, whose addition considerably enhances the separation performance through multiple synergistic effects. A series of factors notably affecting chiral separation are systematically optimized: type and concentration of cyclodextrin, DES, and SC, oil phase type, and pH.

Highly sensitive determination of multiple pesticide residues in foods by supercritical fluid chromatography coupled with ion mobility quadrupole time-of-flight mass spectrometry.

This experiment aimed to establish a green, simple and highly sensitive method (supercritical fluid chromatography (SFC) coupled with ion mobility quadrupole time-of-flight mass spectrometry (IM-Q-TOF/MS)) for the detection of multiple pesticides in foods. During the experiments, several important SFC parameters, such as stationary phase, modifier, make-up solution, back-temperature and back-pressure were optimized. Here, single-field collision cross section (CCS) values and multifield CCS values of 20 pesticides were examined by IM-Q-TOF/MS as highly specific parameters with excellent experimental precision.

Gold-Catalyzed [4 + 1] Heterocyclization of Hydroxamic Acid and Nonactivated Alkyne: A Protocol to Construct 5-Methyl-1,4,2-dioxazole.

A novel gold-catalyzed [4 + 1] heterocyclization of nonactivated alkyne and hydroxamic acid is developed for the regiospecific synthesis of 5-methyl-1,4,2-dioxazole, which is an important structural motif in various bioactive molecules. The current methodology is characterized by high efficiency, simple operation, mild reaction conditions, and good functional group compatibility. Moreover, gram-scale synthesis and synthetic application toward bioactive molecular skeletons have been realized.

Synthesis of heterocyclic ring-fused analogs of HMG499 as novel degraders of HMG-CoA reductase that lower cholesterol.

HMG-CoA reductase (HMGCR) is the rate-limiting enzyme in cholesterol de novo biosynthesis and its degradation may bring therapeutic benefits for the treatment of cardiovascular disease (CVD) and nonalcoholic steatohepatitis (NASH). Before, we disclosed compound HMG499 as a potent HMGCR degrader, which could be a promising agent for treating CVD, however its side-effect of promoting cholesterol accumulation in cells should be eliminated before progression. Herein, a series of novel heterocyclic ring-fused analogs of HMG499 were synthesized and investigated for their activities of stimulating HMGCR degradation using a HMGCR (TM1-8)-GFP reporting system.

Genetic structure of (Diptera: Culicidae) based on COI DNA barcodes.

Gile is a major vector of Japanese encephalitis in China. The population genetics study is crucial as it helps understanding the epidemiological aspects of mosquito-brone diseases and improving vector control measures. Here, the genetic population structure of in the mainland China were estimated using the cytochrome oxidase subunit 1 (COI) DNA barcodes region.