A Rapid Determination of 30 Prohibited Pesticide Residues in Lycii Fructus by UPLC-MS/MS

Prohibited pesticide residues have become one of the main factors affecting the quality and safety of Lycii Fructus,However,rarely studies focus on the rapid determination of these residues.Here,a total of 30 kinds of prohibited pesticide residues were determined by ultra-performance liquid chromatography tandem triple quadrupole mass spectrometry(UPLC-MS/MS)in five different process ways.Pretreatment methods,chromatographic separation and detection conditions in mass spectrometry were all optimized accordingly.Among the five different pretreatment methods,the first and third solid phase extraction failed to provide high recoveries of sulfosulfuron compounds(both lower than 60%).Recovery of chlorphenamidine by the Quick Easy Cheap Effective Rugged and Safe multiresidue method(QuEChERS)was lower than 60%,which did not meet the requirements of trace determination.The concentrations of 30 prohibited pesticides residues treated by straightforward and solid phase extraction showed good linearity in their corresponding ranges,with correlation coefficients over 0.99.The average recoveries of straightforward ranged from 78.13%to 110.9%,while RSD ranged from 1.3%to 16.9%,albeit poor purification was observed.The recovery yield from solid phase extraction was between 67.75%and 103.08%with RSD value from 0.8%to 14.0%,which met the requirements of trace determination,this method has good precision and stability.These results could be employed to other Traditional Chinese Medicines(TCMs)in detecting prohibited pesticide residues.

An optimization of ultra-sonication-assisted extraction from flowers of Apocynum venetum in targeting to amount of free amino acids determined by UPLC-MS/MS

Amino acids are naturally occurring compounds in many edible or medicinal plants,which possess a variety of nutraceutical effects in human.Here,a method of ultrasound-assisted extraction was optimized using Box-Behnken design of response surface methodology in maximizing the yield of free amino acids deriving from flowers of Apocynum venetum L.Under the optimal condition of ultrasound-assisted extraction,i.e.187.5 W of ultrasonic power,31.93 min of extraction time,and 0.47 mg/ml of solid-liquid ratio,the experimental yield of extractive was 287.17±0.205 mg/g,which was in close agreement with the value,as predicted by the established model.In addition,a hydrophilic interaction ultra-high performance liquid chromatography coupled with QqQ-MS/MS method was developed and validated for simultaneous quantification of 20 types of amino acids without derivatization contained in A.venetum flowers.The analytical method was validated by matrix effect,linearity,limit of detection,limit of quantification,precision,repeatability,stability,and recovery.The analysis results showed that A.venetum flower was rich in free amino acids of~3%of total dried weight,and which contained leucine(13.7 g/mg),isoleucine(7.9 g/mg),and lysine(2.2 g/mg)as the most abundant amino acids.Thus,A.venetum flower could provide beneficial nutrient values for human health,e.g.adult weight maintenance or glucose homeostasis.

Interacting with α7 nAChR is a new mechanism for AChE to enhance the inflammatory response in macrophages

Acetylcholine(ACh)regulates inflammation viaα7 nicotinic acetylcholine receptor(α7 nAChR).Acetylcholinesterase(AChE),an enzyme hydrolyzing ACh,is expressed in immune cells suggesting non-classical function in inflammatory responses.Here,the expression of PRiMA-linked G4 AChE was identified on the surface of macrophages.In lipopolysaccharide-induced inflammatory processes,AChE was upregulated by the binding of NF-κB onto the ACHE promotor.Conversely,the overexpression of G4 AChE inhibited ACh-suppressed cytokine release and cell migration,which was in contrast to that of applied AChE inhibitors.AChEmt,a DNA construct without enzymatic activity,was adopted to identify the protein role of AChE in immune system.Overexpression of G4 AChEmt induced cell migration and inhibited ACh-suppressed cell migration.The co-localization ofα7 nAChR and AChE was found in macrophases,suggesting the potential interaction ofα7 nAChR and AChE.Besides,immunoprecipitation showed a close association ofα7 nAChR and AChE protein in cell membrane.Hence,the novel function of AChE in macrophage by interacting withα7 nAChR was determined.Together with hydrolysis of ACh,AChE plays a direct role in the regulation of inflammatory response.As such,AChE could serve as a novel target to treat age-related diseases by antiinflammatory responses.