JOURNAL OF ANALYTICAL TOXICOLOGY
·
2015
·Vol. 39
·期 7
·551-556
·
IF 2.858
Wang Ting,Yu Zhiguo,Shi Yan,Xiang Ping
At the global level, seizures of crystalline methamphetamine (MA) and MA tablets have risen to a new high, indicating that the substance is an imminent threat. MA enantiomer profiling was a useful tool to investigate the prevalence of MA abuse, the intrinsic characteristics of the seized samples and the trends of precursors. In this work, the distribution of enantiomers in clandestine MA crystals and tablets seized mainly in the Yangtze River Delta region, China, from 2008 to 2014 were identified. The MA samples were diluted with internal standard methanol solution, and analyzed by LC–MS-MS. The detection limits of the enantiomers were 0.04 μg/L. The limit of quantification was 0.1 μg/L. As little as 0.2% of the R-enantiomer ratio could be determined. Standard calibration curves of S- and R-MA showed good linearity in the range of 0.1–80 μg/L (r2 > 0.995). All of the seizures were optically pure S-enantiomer in the years 2008 and 2009. Seized samples containing a slight amount of R-MA began to appear in 2010 and increased in the year 2014. No racemic mixture or R-isomer of MA was seized. From this study, we could find out that smuggling routes and/or precursors might be silently changing in the Yangtze River Delta region, China.
研究领域:
分析化学
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法医学
·
药学
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DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2025
·
IF 6.2
Kai Liu,Haoran Li,Alan Kueichieh Chang,Ying Pei,Jianxin Li,Jiao Ai,Wenbao Liu,Tingting Wang,Liuping Xu,Ruiyun Li,Qing Yu,Nan Zhang,Nan Wang,Yuhui Liu,Zhen Jiang,Lijiang Chen,Xiao Liang
Fenbuconazole, a chiral triazole fungicide, is produced and used as a racemate. Previous toxicological research on fenbuconazole in nontarget organisms primarily used the racemate, necessitating an investigation into each enantiomer’s distribution and elimination for safety assessment. In this study, the absolute configurations of fenbuconazole enantiomers were first confirmed by ECD, designating them as S-(+)-fenbuconazole and R-(−)-fenbuconazole based on their optical activity. The UHPLC-QQQ/MS method was selected to systematically study the toxicokinetics and enantiomer conversion of fenbuconazole enantiomers in mice. The results revealed significant enantioselectivity, with S-(+)-fenbuconazole exhibiting 15.11 times higher AUC0–∞ than R-(−)-fenbuconazole, indicating greater blood absorption. In the distribution experiment involving the 14 examined tissues, S-(+)-fenbuconazole consistently exceeded R-(−)-fenbuconazole levels, except in the stomach. Notably, S-(+)-fenbuconazole concentration in the liver was second only to the stomach and was 4.35 times higher than R-(−)-fenbuconazole, suggesting a greater propensity for hepatic accumulation. Molecular docking studies further demonstrated a stronger interaction between S-(+)-fenbuconazole and the CYP2B enzyme in the liver, implying higher hepatotoxic potential. Both enantiomers were rarely excreted in urine or feces, with a cumulative excretion rate below 2.5‰. Enantiomer conversion occurred unidirectionally (R → S) in mice, and the rates were generally low in most tissue. Thus, enantiomeric conversion was not the primary factor driving the enantioselectivity. In summary, R-(−)-fenbuconazole exhibited poor absorption, limited distribution, and a weak interaction with the CYP2B enzyme, which may be considered a low-risk product that could guide monomer development and promote the reduction of pesticide usage.
研究领域:
农药毒理学
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环境科学
·
药代动力学
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DOI
PubMed
高影响因子
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2025
·
IF 2.6
Fang Zhili,Li Xiaoguang,Nie Ying,Zhang Hui,Xu Wenyuan,Nie Qixiang
Two chiral covalent organic polymers (R)-COP and (S)-COP, respectively, were synthesized by Schiff base reaction using tri(4-formyl phenoxy)cyanurate (TFPC) and (1R,2R)-( +)-1,2-Diphenyl-1,2-ethanediamine or (1S,2S)-( +)-1,2-Diphenyl-1,2-ethanediamine as the building blocks. Electrochemical sensors (R)-COP/GCE and (S)-COP/GCE were prepared by coating the two chiral COPs on the surface of glassy carbon electrode (GCE) to detect tryptophan enantiomers. The results showed that both (R)-COP/GCE and (S)-COP/GCE could effectively recognize L-tryptophan (L-Trp) and D-tryptophan (D-Trp). The experimental results indicate that heterochiral interaction had an advantage over homogeneous ones between D-(or L-)Trp and R-(or S-)COP/GCE. Moreover, it was found that there is higher recognition efficiency for tryptophan on (R)-COP/GCE than on (S)-COP/GCE. The obtained (R)-COP/GCE and (S)-COP/GCE electrodes were also used for the determination of tryptophan enantiomer excess (ee), and a good linear relationships were found between the peak current and ee% of tryptophan for both (R)-COP/GCE and (S)-COP/GCE electrodes. Through the optimization of experimental conditions, it is found that there is a good linear relationship between the D-tryptophan concentration on (R)-COP/GCE electrode and the oxidation current in the concentration range of 1 ~ 50 µM and 50 ~ 300 µM D-tryptophan. The detection limit of D-tryptophan was 0.1 µM on (R)-COP/GCE.
研究领域:
分析化学
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生物化学
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DOI
高影响因子
CHIRALITY
·
2017
·Vol. 29
·期 7
·348-357
·
IF 1.956
Hao Wu,Xiaolin He,Huifen Dong,Qingyan Zhou,Yongsong Zhang
Imazethapyr (IM) is a chiral herbicide composed of an (−)-R-enantiomer and an (+)-S-enantiomer with differential herbicidal activity. In this study, the effects of microbial organisms, humidity, and temperature on the selective degradation of the (−)-R- and (+)-S-enantiomers of IM were determined in silty loam (SL) and clay loam (CL) soil with different pH values. The (−)-R-enantiomer of IM was preferentially degraded in two soils under different microorganism, humidity, and temperature conditions. The average half-lives of R-IM ranged from 43 to 66.1 days and were significantly shorter ( P < 0.05) than those of S-IM, which ranged from 51.4 to 79.8 days. The enantiomer fraction (EF = (+)-S-enantiomer/((−)-R-enantiomer + (+)-S-enantiomer)) values were used to describe the enantioselectivity of degradation of IM were >0.5 ( P < 0.05) in two unsterilized soils under different humidity and temperature conditions. The highest EF values were observed at unsterilized CL soil samples under 50% maximum water-holding capacity (MWHC) and 25 °C environmental conditions. The EF values of the IM enantiomers were significantly higher ( P < 0.05) in CL soils (higher pH = 5.81) and were 0.581 (unsterilized) and 0.575 (50% MWHC; 25 °C) compared with those recorded in SL soil (lower pH = 4.85). In addition, this study revealed that microbial organisms preferentially utilized the more herbicidal active IM enantiomer.
研究领域:
环境科学
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土壤微生物学
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农药化学
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DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
·
2018
·
IF 5.123
Datong Wu,Wensheng Tan,Yin Yu,Baozhu Yang,Hongda Li,Yong Kong
Electrochemical enantiorecognition has attracted much interest due to its advantages of low cost and simple equipment. In this work, a new chiral ionic liquid is prepared and applied as an electrolyte for the one-step synthesis of functional graphene sheets (GO-( S , S )-CIL). More importantly, an electrode is modified by the material for the construction of an electrochemical sensor (GO-( S , S )-CIL-GCE). Enantiomers including L/D-tryptophan, ( R )-/( S )-mandelic acid, ( R )-/( S )-malic acid, and L/D-tyrosine are successfully distinguished by GO-( S , S )-CIL-GCE in the response of peak currents to different forms. In addition, the peak potential of the L form is located negatively compared to the D form for tryptophan , and the value of the peak-to-peak potential separation approaches 72 mV. The recognition mechanism is assessed by the density functional theory calculation in detail. In brief, the present method offers great promise for the preparation of functional graphene sheets and their further application in chiral recognition.
研究领域:
材料科学
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电化学
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生物分析化学
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DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2022
·Vol. 190
·期 1
·1-10
·
IF 6.408
Wang Zhongrui,Ji Xinxin,Zhao Jingying,Ji Jie,Li Guangyao,Yang Guang,Xia Hongyan,Hou Juan
Fluorescein-functionalized fluorescent polymer dots (F-PDs) were prepared by a facile one-pot method by magnetic stirring under mild conditions based on carboxymethylcellulose (CMC) and fluorescein as the precursors. The obtained F-PDs exhibited a nanoscale size of 3.2 ± 1.1 nm, excellent water solubility, and bright yellow fluorescence emission with a fluorescence quantum yield of 12.0%. The fluorescent probe displays rapid and sensitive chiral discrimination for lysine focused on different complexation abilities between lysine enantiomers and Cu 2+ . The concentration of L-lysine in the range 4 to 14 mM ( R 2 = 0.997) was measured by the fluorescence intensity ratio ( I 513 / I 429 ); the exitation wavelength was set to λ ex = 365 nm. The detection limit was 0.28 mM (3 σ /slope). Importantly, this sensor accurately predicted the enantiomeric excess (ee) of lysine enantiomers at the designed concentration (lysine: 20 mM; Cu 2+ : 10 mM) ranges. The proposed sensor was successfully applied to determine L-lys (recovery: 95.8–101%; RSD: 0.465–3.34%) and ee values (recovery: 98.5–102%; RSD: 2.61–3.21%) in human urine samples using the standard addition method. Graphical abstract
研究领域:
分析化学
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材料科学
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生物医学工程
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DOI
PubMed
高影响因子
Environmental Science-Water Research & Technology
·
2021
·Vol. 7
·期 7
·1220-1229
·
IF 4.251
Guangqian Yang,Zhengyi Liu,Tingting Lan,Li Dou,Kankan Zhang
A liquid chromatography with tandem mass spectrometry method was developed and applied for the investigation of penthiopyrad photolysation and hydrolysation in different aqueous solutions, and the potential enantioselectivity of this chiral fungicide was further assessed. Good linearity was obtained (R2 > 0.99) for R-(−)- and S-(+)-penthiopyrad in different matrices and the respective limits of detection and quantitation of both enantiomers were 0.003 μg mL−1 and 0.01 μg mL−1. The most suitable illumination intensity for photolysing penthiopyrad was 400 W. Other factors such as pH, salinity and flavonoid also influenced penthiopyrad photolysation. In an acidic solution, the photolytic degradation rate of penthiopyrad enantiomers decreased due to their chemical structures and physicochemical characteristics. Different salinities affected penthiopyrad photolysation differently; acceleration occurred in solutions with salinities of 0.5% or 3.0% due to effective catalysis by photosensitive chloride radical anions, and when the salinity was 1.0% or 2.0%, the inhibitory effect of inorganic salt decreased the photolysation rate. The addition of different flavonoids could significantly inhibit the photolysation of penthiopyrad by decreasing degradation 5–597 times through photo-quenching effects. Under some conditions, the S-(+)-enantiomer was photolysed faster than its antipode, indicating that the photolysation of penthiopyrad was enantioselective. During the hydrolysation process, penthiopyrad degraded faster in the acidic solution than in the other two aqueous solutions with different pH levels, which was attributed to the hydrogen ion-induced catalytic reaction. In sterile/nonsterile natural water matrices, the hydrolysation rate of penthiopyrad enantiomers was also influenced by pH, in the degradation order of tap water (pH 7.1) > rain water (pH 7.3) > lake water (pH 8.8). Enantiopure enantiomers were hydrolysed more slowly than racemic enantiomers due to their mutual promotion effects. The configuration stability of penthiopyrad enantiomers was preserved during the degradation process. Similar enantioselectivities of the hydrolysation of penthiopyrad and preferential degradation of the S-(+)-enantiomer were observed in some aqueous solutions. The results could provide some data to more accurately demonstrate the enantioselective environmental fate and risk of penthiopyrad in aquatic environments.
研究领域:
环境科学
·
农业化学
·
分析化学
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DOI
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
·
2021
·
IF 4.354
Qiaoling Zhang,Hang Feng,Feng Chen,Ze He,Qingle Zeng
A KOH-promoted unusual deoxidative coupling reaction of β-sulfinyl esters with benzylic trimethylammonium salts to produce thioethers is discovered for the first time. If quaternary ammonium salts synthesized from enantiomerically enriched amines are adopted, highly enantiomerically enriched benzyl thioethers (>95–99% ee) with configurations opposite to those of the enantiomerically enriched amines are obtained.
研究领域:
有机化学
·
合成化学
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DOI
PubMed
高影响因子
Nature Communications
·
2022
·Vol. 13
·期 1
·1-14
·
IF 17.694
Arabi Maryam,Ostovan Abbas,Wang Yunqing,Mei Rongchao,Fu Longwen,Li Jinhua,Wang Xiaoyan,Chen Lingxin
Chiral discrimination is critical in environmental and life sciences. However, an ideal chiral discrimination strategy has not yet been developed because of the inevitable nonspecific binding entity of wrong enantiomers or insufficient intrinsic optical activities of chiral molecules. Here, we propose an “inspector” recognition mechanism (IRM), which is implemented on a chiral imprinted polydopamine (PDA) layer coated on surface-enhanced Raman scattering (SERS) tag layer. The IRM works based on the permeability change of the imprinted PDA after the chiral recognition and scrutiny of the permeability by an inspector molecule. Good enantiomer can specifically recognize and fully fill the chiral imprinted cavities, whereas the wrong cannot. Then a linear shape aminothiol molecule, as an inspector of the recognition status is introduced, which can only percolate through the vacant and nonspecifically occupied cavities, inducing the SERS signal to decrease. Accordingly, chirality information exclusively stems from good enantiomer specific binding, while nonspecific recognition of wrong enantiomer is curbed. The IRM benefits from sensitivity and versatility, enabling absolute discrimination of a wide variety of chiral molecules regardless of size, functional groups, polarities, optical activities, Raman scattering, and the number of chiral centers.
研究领域:
环境科学
·
生命科学
·
分析化学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
·
2021
·
IF 6.558
Xiaojuan Zhou,Qiang Liu,Xiaoyu Shi,Chunli Xu,Baoxin Li
In this work, three kinds of gold nanorods (AuNRs) with different aspect ratios were synthesized through conventional seed-mediated growth method, and the chirality of these AuNRs were characterized by circular dichroism (CD) spectroscopy. The results showed that the AuNRs with bigger aspect ratio had larger chirality. The AuNRs with different aspect ratios were applied to distinguish the enantiomers of 19 kinds of α -amino acids. It was found that AuNRs with bigger aspect ratio exhibited the stronger chiral recognition ability. As a proof-of-principle, the AuNRs with the aspect ratio of 4.8 were used to quantitatively recognize enantiomers of valine . Furthermore, the microcalorimetry was applied to study the interaction of AuNRs with amino acid enantiomers. This work provides one method to improve the chiral recognition ability of AuNRs by optimizing the aspect ratio of AuNRs, and helps people better understand the intrinsic chirality of nanostructures .
研究领域:
纳米生物学
·
分析化学
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产品关联
DOI
PubMed
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2023
·
IF 6.8
Yirong Zhang,Zhenchao Tan,Kaikai Qin,Chenglan Liu
Pesticides and heavy metals commonly coexist in soil. In this study, the influence of Cd and Cu on the toxicity of rac -dinotefuran and the enantioselective behavior of dinotefuran enantiomers in soil-earthworm microcosms were investigated. The acute toxic tests showed that S -dinotefuran has higher toxic than that of R -dinotefuran. The rac -dinotefuran and Cd has an antagonistic effect on earthworms, and the Cu and rac -dinotefuran has a synergistic effect. Earthworms maybe promoted the enantioselective behavior of dinotefuran in soil. Co-exposure to Cd or Cu inhibited the dissipation of dinotefuran enantiomers ( S -dinotefuran and R -enantiomers), and slightly reduced the enantioselectivity in soil. The earthworms were found to be preferentially enriched with S -dinotefuran. However, Cd or Cu attenuated the accumulation of dinotefuran enantiomers in earthworms and decreased the enantioselectivity. The effect of Cd and Cu on the environmental behaviors of dinotefuran enantiomers were correlated positively with the dose of Cd/Cu. These results showed that Cd and Cu alter the environmental behaviors and the toxicity of dinotefuran enantiomers in soil-earthworm microcosms. Thus, the influence of coexistent heavy metals on the ecological risk assessment of chiral pesticides should be considered.
研究领域:
环境科学
·
毒理学
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DOI
PubMed
高影响因子
Journal of Analytical Methods in Chemistry
·
2023
·
IF 2.6
Xiaoyu Yang
Simultaneous enantioseparation of three commonly used chiral antifungal pesticides (diniconazole, hexaconazole, and imazalil) was first studied based on micellar electrokinetic chromatography (MEKC) with hydroxypropyl-γ-CD (HP-γ-CD) as chiral selector. In this study, the importance of experimental parameters such as chiral selector type and concentration, sodium dodecyl sulfate (SDS) concentration, the ratio of methanol, and separation voltage in optimizing were investigated. The simultaneous enantioseparation of diniconazole, hexaconazole, and imazalil was successfully achieved in 30 mM borate buffer (pH 9.0) containing 10 mM HP-γ-CD and 20 mM SDS with methanol (8%) added as organic modifiers. The resolution of diniconazole, hexaconazole, and imazalil was 15.2, 2.12, and 2.78, respectively, and the peak efficiency (N) was over 566,825 plates/m. This study provides an alternative way to systematically separate chiral antifungal pesticides with high efficiency.
研究领域:
分析化学
·
农药科学
·
环境科学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）