Co-reporter:Yuqing Duan;Xiaoping Luo;Yu Qin;Haihui Zhang;Guibo Sun;Xiaobo Sun;Yongsheng Yan
Journal of Applied Polymer Science 2013 Volume 129( Issue 5) pp:2882-2890
Publication Date(Web):
DOI:10.1002/app.39002
Abstract
An electrochemical molecularly imprinted polymer (MIP) sensor for detecting the existence of epigallocatechin-3-gallate (EGCG) in tea and its products was successfully developed on the basis of a glassy carbon electrode modified with an electropolymerized nonconducting poly(o-phenylenediamine) film. The properties of the electrode were characterized by cyclic voltammetry, differential pulse voltammetry, and infrared spectroscopy. The template molecules could be rapidly and thoroughly removed by methanol/acetic acid. The linear response range for EGCG was 5.0 × 10−7–1.0 × 10−4 mol/L, and the limit of detection was as low as 1.6 × 10−7 mol/L. The prepared MIP sensor could discriminate between EGCG and its analogs. In addition, satisfactory results were obtained in the detection of real tea samples. The results of our investigation indicate that the MIP sensor was useful for the determination of EGCG with excellent selectivity, high sensitivity, repeatability, and reproducibility. This MIP sensor provides the potential for monitoring the variation of EGCG content during the industrial processes and for predicting the quality of tea and its products. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Co-reporter:Yuqing Duan, Haihui Zhang, Feifei Xu, Bijun Xie, Xianwen Yang, Yong Wang, Yongsheng Yan
Food Chemistry 2010 Volume 122(Issue 1) pp:84-91
Publication Date(Web):1 September 2010
DOI:10.1016/j.foodchem.2010.02.020
Significant growth inhibition effects of procyanidins from lotus (Nelumbo nucifera Gaertn.) seedpod (LSPCs) on mouse melanoma B16 were found both in vivo and in vitro. In vivo treatment with LSPCs inhibited tumour growth in C57BL/6 J mice by 55.3% in terms of average tumour weight. LSPCs can significantly (P < 0.05) decrease lipid peroxidation (LPO) levels and increase the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in liver tissue. In vitro assay of anti-cancer activities suggested that LSPCs (25–100 μg/ml) possessed cytotoxicities against mouse melanoma B16 in a dose-dependent mode. Furthermore, LSPCs had significant (P < 0.05) stimulatory effects on mouse splenocyte proliferation. The prevention of tumour growth was exerted through diverse mechanisms, including cell-cycle arrest, induction of tumour cell death by apoptosis and increase of Ca2+ ions, together with stimulation of antioxidant enzyme activities and immunomodulatory activities.
Co-reporter:Haihui Zhang, Feifei Xu, Yuqing Duan, Xiaoping Luo, ... Xiaobo Sun
IERI Procedia (2013) Volume 5() pp:339-343
Publication Date(Web):1 January 2013
DOI:10.1016/j.ieri.2013.11.113
To separate and enrich EGCG from a mixture of tea catechins, the molecular imprinted polymers (MIPs) were synthesized on silica gel by surface molecular imprinting technique and characterized with Fourier transform infrared spectroscopy (FT-IR), elemental analysis and scanning electronic microscopy (SEM). MIPs exhibited favorable recognition, better selectivity for EGCG than the other monomers, and the descending order was EGCG, (+)-catechin (C), (−)-epicatechin (EC), (−)-epigallocatechin (EGC), (−)-catechin gallate (CG) and (−)-gallocatechin gallate (GCG). These results demonstrated that MIPs could realize the separation and enrichment of EGCG in real sample.
Co-reporter:Xiaoping Luo, Yuqing Duan, Wenya Yang, Haihui Zhang, Changzheng Li, Jixian Zhang
Carbohydrate Polymers (10 February 2017) Volume 157() pp:
Publication Date(Web):10 February 2017
DOI:10.1016/j.carbpol.2016.10.066
•CMP was obtained by subcritical water extraction.•CMP-W1 and CMP-S1 were purified.•Preliminary structural features of CMP-W1 and CMP-S1 were investigated.•CMP-W1 and CMP-S1 displayed immunostimulatory activity in vitro.Water-soluble polysaccharides were obtained from Cordyceps militaris (C. militaris) (CMP) by subcritical water extraction (SWE). Two polysaccharides fractions, CMP-W1 and CMP-S1, were isolated from CMP using DEAE-52 cellulose and Sephadex G-150 column chromatography. The structural characteristics of CMP-W1 and CMP-S1 were investigated. The results showed that the molecular weight of CMP-W1 and CMP-S1 are 3.66 × 105 Da and 4.60 × 105 Da, respectively, and both of them were heteropolysaccharides composed of d-mannose, d-glucose, d-galactose with the molar ratios of 2.84:1:1.29 and 2.05:1:1.09, respectively. FT-IR spectra analysis suggested that CMP-W1 and CMP-S1 belonged to pyranose form sugar and protein free. For immunostimulatory activity assay in vitro, CMP-W1 and CMP-S1 significantly promoted lymphatic spleen cell proliferation of mice. Therefore, the polysaccharides obtained from C. militaris by SWE can be used as potential natural immunostimulant in functional foods or medicine.
