ANALYTICA CHIMICA ACTA
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2014
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IF 4.517
Xiaoyu Mu,Li Qi,Juan Qiao,Xinzheng Yang,Huimin Ma
A chiral ligand exchange capillary electrophoresis (CLE-CE) method using Zn(II) as the central ion and l -4-hydroxyproline as the chiral ligand coordinating with γ-cyclodextrin (γ-CD) was developed for the enantioseparation of amino acids (AAs) and dipeptides. The effects of various separation parameters, including the pH of the running buffer, the ratio of Zn(II) to l -4-hydroxyproline, the concentration of complexes and cyclodextrins (CDs) were systematically investigated. After optimization, it has been found that eight pairs of labeled AAs and six pairs of labeled dipeptides could be baseline-separated with a running electrolyte of 100.0 mM boric acid, 5.0 mM ammonium acetate, 3.0 mM Zn(II), 6.0 mM l -hydroxyproline and 4.0 mM γ-CD at pH 8.2. The quantitation of AAs and dipeptides was conducted and good linearity ( r 2 ≥ 0.997) and favorable repeatability (RSD ≤ 3.6%) were obtained. Furthermore, the proposed method was applied in determining the enantiomeric purity of AAs and dipeptides. Meanwhile, the possible enantiorecognition mechanism based on the synergistic effect of chiral metal complexes and γ-CD was explored and discussed briefly.
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JOURNAL OF SEPARATION SCIENCE
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2015
·Vol. 38
·期 21
·3704-3711
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IF 2.737
Xianrui Liang,Cui Zhao,Weike Su
An ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry method integrating multi-constituent determination and fingerprint analysis has been established for quality assessment and control of Scutellaria indica L. The optimized method possesses the advantages of speediness, efficiency, and allows multi-constituents determination and fingerprint analysis in one chromatographic run within 11 min. 36 compounds were detected, and 23 of them were unequivocally identified or tentatively assigned. The established fingerprint method was applied to the analysis of ten S . indica samples from different geographic locations. The quality assessment was achieved by using principal component analysis. The proposed method is useful and reliable for the characterization of multi-constituents in a complex chemical system and the overall quality assessment of S . indica .
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Acta Biomaterialia
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2017
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IF 6.319
Tianzhou Liu,Dawei Zhang,Wantong Song,Zhaohui Tang,Jiaming Zhu,Zhiming Ma,Xudong Wang,Xuesi Chen,Ti Tong
Combretastatin A4 (CA4) is a leading agent in vascular disrupting strategies for tumor therapy. Although many small-molecule prodrugs of CA4 have been developed to improve its solubility, the overall therapeutic efficiency is moderate. A key reason for this is the reversible effect that CA4 has on tubulin as well as its rapid clearance from plasma and tissues. In this study, we proposed a poly( l- glutamic acid)-CA4 conjugate (PLG-CA4) nanomedicine to fulfill the requirements for fully liberating the potential of CA4 on tumor therapy. Enhanced accumulation and retention of CA4 in tumor tissue, especially, high distribution and gradual release around tumor blood vessels resulted in prolonged vascular disruption and markedly enhanced therapeutic efficiency. We examined and compared the therapeutic effect of PLG-CA4 and commercial combretastatin-A4 phosphate (CA4P) in a murine colon C26 tumor. PLG-CA4 showed significantly prolonged retention in plasma and tumor tissue. Most importantly, the PLG-CA4 was mainly distributed around the tumor vessels because of its low tissue penetration in solid tumor. Pathology tests showed that PLG-CA4 treatment resulted in persistent vascular disruption and tumor damage 72 h after a single injection, this in contrast to CA4P treatment, which showed quick relapse at an equal dose. Tumor suppression tests showed that PLG-CA4 treatment resulted in a tumor suppression rate of 74%, which indicates a significant advantage when compared to tumor suppression rate of the CA4P group, which was 24%. This is the first time that an advantage of the polymeric CA4 nanomedicine with low tissue penetration for solid tumor therapy has been shown. Thus, the results presented in this study provide a new idea for enhancing the tumor therapeutic effect of vascular disrupting agents. Statement of Significance Nanomedicine usually has low tissue penetration in solid tumors, which limits the efficacy of nanomedicine in most cases. But herein, we demonstrate a nanosized vascular disruptive agent (VDA) PLG-CA4 has supper advantages over small molecular combretastatin-A4 phosphate (CA4P) because the PLG-CA4 was mainly distributed around the tumor vessels due to its low tissue penetration in solid tumor.
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MOLECULES
·
2016
·Vol. 21
·期 3
·262
·
IF 2.465
Zhijian Tan,Yongjian Yi,Hongying Wang,Wanlai Zhou,Chaoyun Wang
Background: Ionic liquids (ILs) are considered as green solvents, and widely applied for the extraction of various compounds.Methods: The present research focuses on the extraction of flavonoids fromApocynumvenetumL. leaves by ultrasound-assisted extraction (UAE). Several major influencing factors were optimized. Then, an aqueous biphasic system (ABS) was applied for further isolation of flavonoids.Results: The flavonoids were mainly distributed in the top phase, while impurities were extracted to the bottom phase. The parameters influencing the extraction, namely type and concentration of salt, temperature, and pH, were studied in detail. Under optimized conditions (72.43% IL extract, 28.57% (NH4)2SO4, 25 °C temperature, pH 4.5), the preconcentration factor and extraction efficiency were found to be 3.78% and 93.35%, respectively.Conclusions: This simple and efficient methodology is expected to see great use in the extraction and isolation of pharmaceutically active components from medicinal plant resources.Keywords:ionic liquids;ultrasonic-assisted extraction;flavonoids;aqueous biphasic system;isolation
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International Journal of Polymeric Materials and Polymeric Biomaterials
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2016
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IF 1.667
Zhaosheng Hou,Hao Zhang,Wenqiang Qu,Zhen Xu,Zheng Han
In the study, a new approach for synthesizing biomedical segmented polyurethanes (SPUs) based on polyethylene glycol (PEG, Mn = 800), poly(ε-caprolactone-co-D,L-lactide) (PCLA) and aliphatic diurethane diisocyanates with a long uniform hard segment was developed. By the chain extension of a mixture of PEG diol and PCLA diol with diurethane diisocyanates based on inexpensive 1,6-hexanediisocyanate, three SPUs (SPU-I, SPU-II, and SPU-III) with different contents of hydrophilic segments (PEG) and hard segments were obtained. The chemical structures of diurethane diisocyanates, PCLA and SPUs were confirmed by 1H NMR, 13C NMR, FT-IR, HR-TOF-MS, and GPC. The SPU films exhibited similar thermostability, indicating that the hard segment content marginally affects on the thermostability. From the results of differential scanning calorimetry, two glass transition temperatures were observed, suggesting the microphase separation of soft and hard segments. The SPU films exhibited satisfactory mechanical properties with ultimate stress of 17.4–22.3 MPa and strain at break of 890–1060%, and the initial modulus increased with the increasing content of hard segments. In vitro degradation studies indicated that the time of SPU films to become fragments was 22–33 days, and the degradation rate increased with the increasing content of hydrophilic segments in SPU. Hence, the degradation time of SPU films could be controlled by adjusting the PEG content in SPU, which made them good candidates for further biomedical applications. Studies of in vitro drug release were conducted using vitamin B1 as model drugs. Drug-loaded films exhibited a high initial release rate and matrix-controlled release for more than two weeks, thereby demonstrating a promising material for a long-acting controlled release system. Cytotoxicity test of film extracts and cell attachment on the film surface were conducted using L929 mouse fibroblasts, and the results indicated that the SPU films possess excellent cytocompatibility and cell adhesive ability.
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FOOD CHEMISTRY
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2016
·
IF 4.052
Jiang-Lin Li,Da-Wen Sun,Hongbin Pu,Digvir S. Jayas
Surface-enhanced Raman scattering (SERS) imaging coupling with multivariate analysis in spectral region of 200 to 1800 cm −1 was developed to quantify and visualize thiophanate-methyl (TM) and its metabolite carbendazim residues in red bell pepper ( Capsicum annuum L.). Least squares support vector machines (LS-SVM) and support vector machines (SVM) models based on seven optimized characteristic peaks that showed SERS effects of TM and its metabolite carbendazim residues were employed to establish prediction models. SERS spectra with first derivative (1st) and second derivative (2nd) method were subsequently compared and the optimized model of 1st-LS-SVM acquired showed the best performance (RPD = 6.08, R 2 P = 0.986 and RMSEP = 0.473). The results demonstrated that SERS imaging with multivariate analysis had the potential for rapid determination and visualization of the trace TM and its metabolite carbendazim residues in complex food matrices.
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Processes
·
2024
·Vol. 12
·期 11
·2598
·
IF 2.8
Xiaofei Li,Tianfu Li,Xiaohu Jin,Yanfu Wei,Yanping Bao,Qian Yao,Fuhua Li,Weicheng Xu,Xiaolian Wu
The adsorption of toxic metals onto iron oxides is a prevalent geochemical process in natural environments. Organic acids are known to modify the adsorption features of toxic ions through either competitive or cooperative effects. Nowadays, the toxic metal adsorption influenced by organic acids on iron oxides with varying facet exposures is not fully understood. This study explored how L-Aspartic acid (LA) influences Cr(VI) adsorption on two different exposure facets of lepidocrocite through batch adsorption experiments, in situ ATR-FTIR spectroscopy, and 2D-COS analysis. The results reveal that LA competes for available binding sites on lepidocrocite, consequently inhibiting the adsorption of Cr(VI). Rod-shaped lepidocrocite (R-LEP) owns more (001) facets and shows stronger Cr(VI) adsorption and LA competition than plate-like lepidocrocite (P-LEP), which mainly has (010) facets. The data for Cr(VI) uptake on both P-LEP and R-LEP within the effect of LA are well-fitted by the pseudo-second-order kinetics and the Freundlich isotherm model, suggesting chemical interaction as the dominant process for Cr(VI) coordination on lepidocrocite. Cr(VI) ions favor interaction with R-LEP over P-LEP, forming inner-sphere complexes on (001) facets. Concurrently, LA’s carboxyl groups can compete for the active sites on the lepidocrocite surfaces, engaging in anion exchange with hydroxyl groups, and forming outer-sphere and inner-sphere structures. This competitive effect is particularly pronounced in the R-LEP system. The current findings are expected to broaden insights into how the exposed facets of lepidocrocite influence the fate of Cr(VI) in the organic acid coexistence environment.
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ELECTROCHIMICA ACTA
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2017
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IF 4.798
Yuan Chen,Xiao-Mi Liu,Xi Wu,Xue-Chen Liu,Wen-Hao Dong,Bing-Kai Han,Xin Du,Cong Zhang,Yan-Yan Zhang,Hong-Tao Wang,Qiang Chen
Novel approachs to functionalize carboxylated multi-walled carbon nanotubes (CMWCNTs) array with poly- l -histidine (PLH) on a self-assembled monolayer (SAM) of 4-aminothiophenol (4ATP) were developed for the first time. With help of π–π interaction and chelation of the side imidazole groups in poly- l -histidine, the array showed efficient electron transfer and mild biocompatibility. By immobilizing glucose oxidase (GOx) to AuNPs electrodeposited on the array, a high-powered glucose biosensor with excellent electrocatalytic performance was fabricated and applied for glucose determination in human serum samples. The prepared biosensor exhibited highly sensitive response to glucose under the operating voltage of 600 mV with sensitivity of 96.04 μA mM −1 cm −2 , linear range of 0.005–6.5 mM, lowest detection limit (LOD) of 0.7 μΜ (S/N = 3) and Michaelis constant ( K M ) of 3.92 mM. Compared with other glucose sensors previously reported, this work showed higher sensitivity, lower detection limit and wider linear range. Furthermore, the developed array may provide a promising platform for various biosensors fabrication.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2024
·
IF 7.7
Abid Naeem,Chengqun Yu,Xiaoli Wang
Glycyrrhiza glabra Linn (liquorice) has been widely used for therapeutic purposes to treat digestive disorders, immunomodulatory disorders, inflammatory disorders, diabetes, viral infections, and cancer. Liquorice contains a wide variety of bioactive compounds, including glycyrrhizin, flavonoids, and terpenoids. Several factors compromise their therapeutic efficacy, such as poor pharmacokinetic profiles and physicochemical properties. Therefore, to improve its overall effectiveness, liquorice solid dispersion (LSD) was incorporated into biopolymer-based guar gum-grafted-2-acrylamido-2-methylpropane sulfonic acid (Guar gum- g -AMPS) hydrogels designed for controlled delivery via the oral route and characterized. The qualitative analysis of LSD revealed 51 compounds. Hydrogel structural properties were assessed for their effect on swelling and release. The highest swelling ratio (6413 %) and drug release (84.12 %) occurred at pH 1.2 compared to pH 7.4 (swelling ratio of 2721 % and drug release of 79.36 %) in 48 h. The hydrogels exhibited high porosity (84.23 %) and biodegradation (9.30 % in 7 days). In vitro hemolysis tests have demonstrated the compatibility of the hydrogel with blood. CCK-8 assay confirmed the biocompatibility of the synthesized hydrogel using osteoblasts and RIN-m5f cells. LSD exhibited good anti-inflammatory activity when loaded into hydrogels after being subjected to protein denaturation experiments. Moreover, LSD-loaded hydrogels have good antioxidant and antibacterial properties.
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JOURNAL OF SOILS AND SEDIMENTS
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2024
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IF 2.8
Cheng Congcong,Chen Haijun,Xu Nan,Zhang Shan
Purpose The Cr(VI) removal capacity of green synthesized nano-zero-valent iron (GnZVI) using tea polyphenols (TPs) remains limited. To improve their application in contaminated soil and groundwater, the GnZVI was modified. This is necessary for in-situ remediation of heavy metal-contaminated soil and groundwater. Materials and methods The GnZVI-based carbon-composite (L&GnZVI@BC) was successfully constructed via the synergistic effect of L-cysteine modification and biochar support. The Cr(VI) removal capacity and transportability of L&GnZVI@BC were investigated in soil–water system by batch and column experiments. Results and discussion Comparison with two materials of GnZVI separately modified by L-cysteine (L-GnZVI) or supported by biochar (GnZVI@BC)), GnZVI composite with a combination modification of L-cysteine and biochar (L&GnZVI@BC, L-cysteine/biochar/Fe = 0.1/0.1/1) showed a much higher Cr(VI) removal capacity in soil and groundwater. The synergistic effect of the reduction of L-cysteine functional groups and the dispersibility of biochar support can enhance the transportability of L&GnZVI@BC in water-saturated sand media for more Cr(VI) adsorption at neutral pH; while that improved the soluble Fe(II) released from composite for the higher reduction of Cr(VI) into Cr(III) at acidic pH. Particularly, L&GnZVI@BC favored more Cr(III) generation during transport in porous media at lower pH when applied in the treatment of Cr(VI) contamination. Conclusion This research highlights that the modification of both L-cysteine and biochar was beneficial to sufficient transport and efficient remediation in Cr(VI)-contaminated soil and groundwater environments at different pH ranges. This study’s results provide a theoretical support for the practical application of nZVI composites in in-situ remediation of Cr(VI)-contaminated soil and groundwater via an environmental-friendly approach.
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CARBOHYDRATE POLYMERS
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2024
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IF 10.7
Jun Yang,Shuzhen Ma,Sihong Tao,Muci Wu,Qian Wu,Jingyi Wang
β-Galactosidase (lactase) plays a crucial role as a dietary supplement in managing lactose intolerance. Here, the catalytic activity of lactase was successfully activated for the first time through complexation with water-extractable β-glucans from highland barley (WHBG). Under simulated gastric/small intestinal digestive conditions, WHBG and lactase spontaneously formed complexes, resulting in a remarkable increase in catalytic activity up to 172.6 %. Structural analyses revealed that the incorporation of WHBG caused partial unfolding of lactase, thereby exposing its hydrophobic regions with active sites, and the electrostatic and hydrophobic interactions between the two played pivotal roles. Meanwhile, according to microstructure and particle size analyses, the dissociation of aggregates and the re-distribution of lactase molecules were also observed. Consequently, the enzyme-substrate contact was promoted, and the hydrolysis efficiency of complexed lactase in the digestion of lactose in milk was superior to that of native lactase. Notably, among WHBG30/50/70 obtained by continuous fractionation of WHBG with 30 %/50 %/70 % ethanol, WHBG70 exhibited the lowest molecular weights and size, and the highest negative ζ-potential, potentially contributing to its superior activation abilities on lactase. These findings challenge the traditional view of polysaccharides as enzyme inhibitors and highlight their potential for diverse applications.
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Acta Pharmaceutica Sinica B
·
2025
·
IF 14.6
Jiahui Chen,Liping Zhang,Ting Xie,Xiao Zhang,Congcong Pan,Fangli Sun,Wenfeng Li,Zhijie Sun,Deli Dong
The clinical antiprotozoal drug nitazoxanide has been demonstrated to improve the experimental diabetes mellitus, lipid metabolism disorders, atherosclerosis and inhibit inflammation. Since the pathogenesis of heart failure with preserved ejection (HFpEF) is multifactorial and closely associated with the aforementioned diseases, we aim to study the effect of nitazoxanide on high-fat diet (HFD) plus L-NAME (N ω -nitro-L-arginine methyl ester)-induced HFpEF and metabolic syndrome in mice. We found that oral nitazoxanide improved cardiac hypertrophy, cardiac fibrosis, cardiac diastolic dysfunction, increased blood pressure, impaired exercise tolerance, impaired glucose handling, serum lipid disorders, hepatic steatosis, increased weight of white adipose tissues and kidney fibrosis in HFD+L-NAME-treated mice. In the established HFD+L-NAME-induced HFpEF and metabolic syndrome mouse model, therapeutic treatment with nitazoxanide rescued HFD+L-NAME-induced pathological phenotypes as mentioned above. The in vitro experiments revealed that tizoxanide, the active metabolite of nitazoxanide, increased the basal mitochondria metabolism of cardiomyocytes, inhibited cardiomyocyte hypertrophy and collagen secretion from cardiac fibroblasts, and relaxed phenylephrine- and U46619-induced constriction of rat mesenteric arteries, indicating that the direct effect of tizoxanide might partly contribute to the protective effect of nitazoxanide against HFpEF in vivo . The present study suggests that nitazoxanide might be a potential drug for HFpEF and metabolic syndrome therapy.
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