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Zhong J.-S.,Sun Yat Sen University | Wan J.-Z.,Sun Yat Sen University | Ding W.-J.,Sun Yat Sen University | Wu X.-F.,Chinese Academy of Sciences | And 2 more authors.
Journal of Pharmaceutical and Biomedical Analysis | Year: 2015

A quality control strategy using high-performance liquid chromatography-diode array detector-electrospray ionization-tandem mass spectrometry (HPLC-DAD-ESI-MS/MS) coupled with chemometrics analysis was proposed for Aloe barbadensis Miller. Firstly, the extraction conditions including methanol concentration, extraction time and solvent-to-material ratio were optimized by multi-responses optimization based on response surface methodology (RSM). The optimum conditions were achieved by Derringer's desirability function and experimental validation implied that the established model exhibited favorable prediction ability. Then, HPLC fingerprint consisting of 27 common peaks was developed among 15 batches of A. barbadensis samples. 25 common peaks were identified using HPLC-DAD-ESI-MS/MS method by their spectral characteristics or comparison with the authentic standards. Chemometrics techniques including similarity analysis (SA), principal components analysis (PCA) and hierarchical clustering analysis (HCA) were implemented to classify A. barbadensis samples. The results demonstrated that all A. barbadensis samples shared similar chromatographic patterns as well as differences. These achievements provided an effective, reliable and comprehensive quality control method for A. barbadensis. © 2015 Elsevier B.V. Source


Ding W.-J.,Sun Yat Sen University | Wu X.-F.,Chinese Academy of Sciences | Wu X.-F.,Hainan Provincial Key Laboratory of Quality and Safety for Tropical Fruits and Vegetables | Zhong J.-S.,Sun Yat Sen University | Wan J.-Z.,Sun Yat Sen University
International Journal of Food Science and Technology | Year: 2014

Summary: This study explored the stability and degradation products of aloin A under varying pH, temperature and light conditions usually encountered in processing. The stability of aloin A was significantly affected by temperature and pH. The content of aloin A decreased by more than 90% within 12 h at 50 °C and within 6 h at 70 °C, respectively. A significant decrease in stability was also observed at higher pHs. At pH 8.0, less than 2% of aloin A remained within 12 h. However, aloin A exhibited good stability at acidic pH levels with 94% remaining at pH 2.0 for 14 days. Light exerted no influence on the stability during the experimental period (14 days). Aloe-emodin, elgonica-dimers A and B were characterised as major degradation products of aloin A at pH 5.0 or below, and elgonica-dimers were mainly formed at 4 °C as well. 10-hydroxyaloins A and B were found under any condition except at pH 2.0 and 3.0, and they were mainly formed under high temperature, neutral-basic and any light conditions. This study investigated the stability and degradation products of aloin A under varying pH, temperature and light conditions. © 2014 Institute of Food Science and Technology. Source


Zhong J.-S.,Sun Yat Sen University | Wan J.-Z.,Sun Yat Sen University | Liu Y.-P.,Sun Yat Sen University | Ding W.-J.,Sun Yat Sen University | And 3 more authors.
Analytical Methods | Year: 2014

Multi-component analysis has been considered to be one of the key techniques for quality control of traditional Chinese medicines. However, the shortage and high cost of reference standards have become the greatest obstacles in implementing this goal. An alternative method using only an easily available reference standard as the internal standard to determine multiple analogues has gained increasing attention. In the present study, a practical HPLC method was established for the simultaneous quantification of seven chromones in Aloe barbadensis Miller using a single reference standard. An easily available compound in the plant named 8-C-glucosyl-7-O-methyl-(S)-aloesol (3) was selected as the internal standard, and the other six chromones were determined by their relative response factors. The results indicated that the established method was accurate and reliable for the routine quality control of A. barbadensis. 6 batches of A. barbadensis samples were analyzed using this method and no significant difference was observed in the results obtained using the established method and external standard method. The newly developed method can serve as an alternative approach when reference standards are difficult to obtain. This achievement would promote the quality control of A. barbadensis. © 2014 the Partner Organisations. Source


Zhong J.-S.,Sun Yat Sen University | Wan J.-Z.,Sun Yat Sen University | Jiang X.-Q.,Sun Yat Sen University | Ding W.-J.,Sun Yat Sen University | And 3 more authors.
Separation Science and Technology (Philadelphia) | Year: 2015

A bioactive chromone, 8-C-glucosyl-7-O-methyl-(S)-aloesol (compound 1), was prepared by the acid-catalyzed hydrolysis of isoaloeresin D in Aloe barbadensis Miller. The hydrolysis conditions were successfully optimized by response surface methodology (RSM). The results indicated that RSM in the present study was adequate and effective. Then, reversed-phase flash chromatography was utilized for the isolation. In a one-step operation within 45 min, 26 mg of compound 1 was isolated from 153 mg of hydrolysis product, with a purity of 99.3%. These achievements would afford sufficient amount of high pure compound for chromatographic purpose and pharmacological activity screening. © , Copyright © Taylor & Francis Group, LLC. Source


Li S.,Chinese Academy of Agricultural Sciences | Li S.,Hainan Provincial Key Laboratory of Quality and Safety for Tropical Fruits and Vegetables | Wu X.,Chinese Academy of Agricultural Sciences | Wu X.,Hainan Provincial Key Laboratory of Quality and Safety for Tropical Fruits and Vegetables | And 4 more authors.
Microchimica Acta | Year: 2016

The authors describe a nanomaterial for solid-phase extraction of carbendazim. Magnetic molecularly imprinted polymer nanoparticles (mag-MIP-NPs) were obtained by immobilizing the MIP and a thiolated β-cyclodextrin on the surface of magnetite (Fe3O4) nanoparticles coated with gold nanoparticles. Both the recognition sites of the MIP and the hydrophobic cavities in the β-cyclodextrin contribute to the specific molecular recognition and extraction of carbendazim. The mag-MIP-NPs have an apparent adsorption capacity of 190 mg⋅g‾1. Spiked vegetables were analyzed by using this material for extraction of carbendazim prior to its determination by ultra performance liquid chromatography (UHPLC). Recoveries range from 90.5 % to 109 %, and the detection limit is 3.0 pg⋅mL‾1. [Figure not available: see fulltext.] © 2016 Springer-Verlag Wien Source

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