Synthesis of dihalogenated coumarin derivatives for monitoring acid phosphatase activity

Aim To synthetize 6-chloro-8-fluoro-4-methylumbelliferone phosphate(CF-MUP) and utilize it to analyze acid phosphatase activity.Method CF-MUP obtained by phosphorylation of CFMU(6-chloro-8-fluoro-4-methylumbelliferone) which was prepared by Pechmann reaction between 4 and ethyl acetoacetate in the presence of methanesulfonic acid.And then,the utility of CF-MUP as a substrate for acid phosphatase was compared with MUP(4-methylumbelliferone phosphate).Results The new coumarin phosphate,CF-MUP,demonstrated much higher sensitivity and was more robust for detecting the activity of acid phosphatase than MUP in the physiological pH range.Conclusion This new fluorescence dye,CF-MUP,is a convenient tool for the continuous assay of acid phosphatases with a wide range of pH.

Dihalogenated nitrophenols in drinking water:Prevalence,resistance to household treatment,and cardiotoxic impact on zebrafish embryo

Dihalogenated nitrophenols(2,6-DHNPs),an emerging group of aromatic disinfection byproducts(DBPs)detected in drinking water,have limited available information regarding their persistence and toxicological risks.The present study found that 2,6-DHNPs are resistant to major drinking water treatment processes(sedimentation and filtration)and households methods(boiling,filtration,microwave irradiation,and ultrasonic cleaning).To further assess their health risks,we conducted a series of toxicology studies using zebrafish embryos as the model organism.Our findings reveal that these emerging 2,6-DHNPs showed lethal toxicity 248 times greater than that of the regulated DBP,dichloroacetic acid.Specifically,at sublethal concentrations,exposure to 2,6-DHNPs generated reactive oxygen species(ROS),caused apoptosis,inhibited cardiac looping,and induced cardiac failure in zebrafish.Remarkably,the use of a ROS scavenger,N-acetyl-l-cysteine,considerably mitigated these adverse effects,emphasizing the essential role of ROS in 2,6-DHNP-induced cardiotoxicity.Our findings highlight the cardiotoxic potential of 2,6-DHNPs in drinking water even at low concentrations of 19μg/L and the beneficial effect of N-acetyl-l-cysteine in alleviating the 2,6-DHNP-induced cardiotoxicity.This study underscores the urgent need for increased scrutiny of these emerging compounds in public health discussions.

Determination of Hyoscine Butylbromide with Ag＋ and Dihalogenated Fluorescein Dyes in Capsules by Resonance Rayleigh Scattering Method Coupled with Flow Injection Analysis Techniquet

In pH 4.2-5.2 HOAc-NaOAc buffer solution, Ag＋ reacted with dihalogenated fluorescein （DHF） dyes to form a 1 ; 2 anionic complex. This anionic complex could further react with hyoscine butylbromide （HBB） to form 1 ： 1 ion-association complex, which resulted in the significant enhancement of resonance Rayleigh scattering （RRS） intensity. Therefore, a novel method for the determination of HBB by resonance Rayleigh scattering （RRS） coupled with flow injection analysis （FIA） technique has been established. The present method had been applied to determine HBB in capsules and the results were in good agreement with those obtained by the literature method.

Delocalizedπ_(3)^(6) Bond in OX_(2) (X=Halogen) Molecules

OX_(2)(X=halogen)molecules was studied theoretically.Calculation results show that delocalizedπ_(3)^(6) bonds exist in their electronic structures and O atoms adopt the sp^(2) type of hybridization,which violates the prediction of the valence shell electron pair repulsion theory of sp^(3) type.Delocalization stabilization energy is proposed to measure the contribution of delocalizedπ_(3)^(6) bond to energy decrease and proves to bring extra-stability to the molecule.These phenomena can be summarized as a kind of coordinating effect.