JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2021
·
IF 5.279
Pengfei Liu,Jiaojiao Zhang,Yan Qiao,Xianglin Hou,Yu Liu,Yingxiong Wang
Using environment-friendly catalysts to convert biomass into compounds with high values is one of the central topics of green chemistry. In this work, [Ch][Pro] (cholinium as the cation and l-proline as the anion) ionic liquid was synthesized and applied as a model catalyst in the production of deoxyfructosazine (DOF) and fructosazine (FZ) from d-glucosamine (GlcNH2). The 13C NMR chemical shift titration experiments and the diffusion-ordered NMR spectroscopy (DOSY) measurements showed that, when the [Ch][Pro] interacted with GlcNH2, the l-proline anion ([Pro]−) played a major catalytic role instead of cholinium cation ([Ch]+). The effects of the reaction temperature and the amount of [Ch][Pro] on the product yields were surveyed. The experimental results showed that the highest DOF yield (33.78%) was obtained after 30 min at 100 °C when the molar ratio of [Ch][Pro]/GlcNH2 was 1. Moreover, in situ1H NMR and in situ13C NMR experiments were applied to monitor the reaction process with [Ch][Pro] as the catalyst. The reactive intermediate, dihydrofructosazine, was clearly detected by these in situ techniques. Accordingly, a possible reaction pathway was proposed. By applying other amino acids as the anions, we also prepared five other [Ch][AA] ionic liquids, and they showed different catalytic activities and selectivity in the GlcNH2 self-condensation reaction.
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高影响因子
Materials Today Communications
·
2021
·
IF 3.383
Xiangping Hao,Jingzhi Yang,Lei Zhang,Chenhao Ren,Wen Li,Yuntian Lou,Hongchang Qian,Shougang Chen,Dawei Zhang
Bacterial infections, as one of the main reasons for failure of metallic implants, can increase morbidity and mortality. In this study, polydopamine/graphene oxide- d -leucine (PDA/GO-Leu) films that possess pH-responsive antibacterial and anti-adhesion properties were synthesized by the soaking method. Due to the unique features of ampholyte, d -leucine has the same type of charge as the immobilized GO surface when the pH value of the environment is identical to that of the humoral environment. It contributes to the d -leucine release from the GO surface and exerts antibacterial and anti-adhesion effects of such films. The synergistic actions between d -leucine and GO of such films were analyzed by the table colony counting method and dead/live fluorescence. The results indicated that the released d -leucine is the key point within this multilayer system. The PDA/GO-Leu films exhibited both outstanding antibacterial and anti-adhesion properties for E. coli and S. aureus, respectively when pH of the culture medium was 7.4. Meanwhile, the cytotoxicity of the PDA/GO-Leu films was evaluated by CCK-8 and dead/live fluorescence, and the results demonstrated that such films have good biocompatibility.
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Bioresources and Bioprocessing
·
2021
·Vol. 8
·期 1
·1-15
·
IF 4.578
Tan Xu,Zhang Sheng,Song Wei,Liu Jia,Gao Cong,Chen Xiulai,Liu Liming,Wu Jing
In this study, a four-enzyme cascade pathway was developed and reconstructed in vivo for the production of d - p -hydroxyphenylglycine (D-HPG), a valuable intermediate used to produce β-lactam antibiotics and in fine-chemical synthesis, from l -tyrosine. In this pathway, catalytic conversion of the intermediate 4-hydroxyphenylglyoxalate by meso -diaminopimelate dehydrogenase from Corynebacterium glutamicum ( Cg DAPDH) was identified as the rate-limiting step, followed by application of a mechanism-guided “conformation rotation” strategy to decrease the hydride-transfer distance d (C6HDAP−C4NNADP) and increase Cg DAPDH activity. Introduction of the best variant generated by protein engineering ( Cg DAPDH BC621/D120S/W144S/I169P with 5.32 ± 0.85 U·mg −1 specific activity) into the designed pathway resulted in a D-HPG titer of 42.69 g/L from 50-g/L l -tyrosine in 24 h, with 92.5% conversion, 71.5% isolated yield, and > 99% enantiomeric excess in a 3-L fermenter. This four-enzyme cascade provides an efficient enzymatic approach for the industrial production of D-HPG from cheap amino acids.
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BASIC & CLINICAL PHARMACOLOGY & TOXICOLOGY
·
2020
·Vol. 128
·期 5
·661-668
·
IF 2.651
Hongfang Li,Yunyan Tang,Weipeng Wei,Chengchen Yin,Fushan Tang
Saikosaponin-d (SSd) is a major bioactive triterpenoid saponin extracted from Bupleurum , which has anti-inflammatory, anticancer, antioxidative and anti-hepatic fibrosis effects. Due to the effects of Bupleurum -related formulations on cytochrome P450 (CYPs) expression still remain unclear, the combination therapies involved formulations containing Bupleurum may sometimes lead to unexpected drug-drug interactions in clinical practice. These interactions can limit the clinical applications of related formulations. In this study, we tried to explore the effects of SSd on CYP3A4 mRNA, protein expression and the enzyme activity in HepaRG cells by real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR), Western blot (WB) and HPLC method, respectively. The interaction between SSd and CYP3A4 was analysed by molecular docking. HepaRG cells were cultured with different concentrations of SSd (0.5, 1, 5 and 10 μmol/L) for 72 hours. It is revealed that SSd can inhibit CYP3A4 mRNA and its protein expression, and also the enzyme activity. Molecular docking study demonstrated that SSd can bind to several key active sites of amino acid residues of CYP3A4 protein with hydrogen bonds and hydrophobic interactions. Thus, drug-drug interactions resulted by SSd inhibiting CYP3A4 need attention when formulations containing SSd or Bupleurum are co-administrated with drugs metabolized by CYP3A4.
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INTERNATIONAL JOURNAL OF ONCOLOGY
·
2020
·Vol. 57
·期 1
·183-196
·
IF 3.899
Fengqi Jiang,Yaodong Chen,Shuo Ren,Zizhuo Li,Kan Sun,Yanwei Xing,Yuekun Zhu,Daxun Piao
Cyclovirobuxine D (CVB‑D) is an alkaloid, which is mainly derived from Buxus microphylla. It has been reported that CVB‑D has positive effects on breast cancer, gastric cancer and other malignant tumors. However, to the best of our knowledge, there are no reports regarding the effects of CVB‑D on colorectal cancer (CRC). The purpose of the present study was to determine the anticancer effects of CVB‑D and further elucidate its molecular mechanism(s). DLD‑1 and LoVo cell lines were selected to evaluate the antitumor effect of CVB‑D. Cytotoxicity, viability and proliferation were evaluated by the MTT and colony formation assays. Flow cytometry was used to detect the effects on apoptosis and the cell cycle in CVB‑D‑treated CRC cells. The migration and invasion abilities of CRC cells were examined by wound healing and Transwell assays. In addition, RNA sequencing, bioinformatics analysis and western blotting were performed to investigate the target of drug action and clarify the molecular mechanisms. A xenograft model was established using nude mice, and ultrasound was employed to assess the preclinical therapeutic effects of CVB‑D in vivo. It was identified that CVB‑D inhibited the proliferation, migration, stemness, angiogenesis and epithelial‑mesenchymal transition of CRC cells, and induced apoptosis and S‑phase arrest. In addition, CVB‑D significantly inhibited the growth of xenografts. It is notable that CVB‑D exerted anticancer effects in CRC cells partly by targeting collagen triple helix repeat containing 1 (CTHRC1), which may be upstream of the AKT and ERK pathways. CVB‑D exerted anticancer effects through the CTHRC1‑AKT/ERK‑Snail signaling pathway. Targeted therapy combining CTHRC1 with CVB‑D may offer a promising novel therapeutic approach for CRC treatment.
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THERMOCHIMICA ACTA
·
2020
·
IF 2.762
Jiacheng Ji,Sum-Wai Chiang,Mengjing Liu,Xin Liang,Jia Li,Lin Gan,Yanbing He,Baohua Li,Feiyu Kang,Hongda Du
In this work, we report a fabrication of oriented carbon fibres/alumina/silicon rubber composites by 3-D printing. The 3-D printed composites possess higher thermal conductivity up to 7.36 W/m K at 12 vol% CFs and 30 vol% alumina loading than that of cast composites (4.22 W/m K) at the same components. The orientation caused by 3-D printing produces a synergism of the thermal conductivity enhancement for CFs and alumina hybrid filled composites. We attribute the synergism to the decrease of thermal interface resistance, while the reduction of thermal interface resistance has a bigger effect on thermal conductivity of CASR composites. This study provides a novel way to obtain thermal conductive composites with orientation, which has a great significance for the development of high-performance thermal conductive products.
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JOURNAL OF CEREAL SCIENCE
·
2019
·
IF 2.452
Feier Cheng,Xinhui Ge,Caifeng Gao,Yunlong Li,Min Wang
Epidemiological studies have shown that D-chiro-inositol (DCI) has multiple health effects in humans. Buckwheat , a nutritional staple crop, is a dietary source of DCI. We established a new economic method to accurately detect DCI content in buckwheat samples and investigated the antioxidant effect of DCI. In this study, we analyzed the content and form of DCI in buckwheat with different varieties, growth stages, and milled parts of seeds using pre-column derivatization and high performance liquid chromatography-ultraviolet detection. The total DCI content of ZK-2 and DT-1 was the highest. During buckwheat growth, DCI content was the highest in mature leaves. DCI was mainly in bound form in flowers and grains and mainly in free form in roots and stems. The highest content of DCI was 60–100-mesh in size in buckwheat grains. The results of cell experiments showed that DCI can inhibit the oxidative stress of HepG2 cells induced by palmitic acid (PA). This study will assist in the processing and utilization of buckwheat and provide an important basis for the scientific and effective use of D-chiro-inositol resources to increase the maximization of buckwheat resources.
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CHEMISTRY & BIODIVERSITY
·
2019
·Vol. 16
·期 8
·e1900232
·
IF 1.449
Wen-Jun Xue,Jian-Yao Du,Ya-Hui Deng,Zhong-Hui Yan,Ji-Ping Liu,Yu Liu,Li-Ping Sun
Vascular endothelial growth factor receptor-2 (VEGFR-2) plays an important role in both vasculogenesis and angiogenesis. Inhibition of VEGFR-2 has been demonstrated as a key method against tumor-associated angiogenesis. Thiazolopyrimidine is an important analog of the purine ring, and we choose the thiazolopyrimidine scaffold as the mother nucleus. Two series of thiazolo[5,4- d ]pyrimidine derivatives were synthesized and evaluated for their antiproliferative activity. In HUVEC inhibition assay, compounds 3l (=1-(5-{[2-(4-chlorophenyl)-5-methyl[1,3]thiazolo[5,4- d ]pyrimidin-7-yl]amino}pyridin-2-yl)-3-(3,4-dimethylphenyl)urea) and 3m (=1-(5-{[2-(4-chlorophenyl)-5-methyl[1,3]thiazolo[5,4- d ]pyrimidin-7-yl]amino}pyridin-2-yl)-3-(4-methoxyphenyl)urea) exhibited the most potent inhibitory effect (IC 50 =1.65 and 3.52 μ m , respectively). Compound 3l also showed the best potency against VEGFR-2 at 50 μ m (98.5 %). These results suggest that further investigation of compound 3l might provide potential angiogenesis inhibitors. Graphical
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POLYMER
·
2018
·
IF 3.483
Yanyun Li,Tao Jing,Gaofeng Xu,Jingzhi Tian,Mengyao Dong,Qian Shao,Bin Wang,Zhikang Wang,Yongjie Zheng,Changlong Yang,Zhanhu Guo
Three-dimensional magnetic graphene oxide-magnetite polyvinyl alcohol (3D-GO/PVA/Fe 3 O 4 ) nanocomposites were successfully prepared. The morphology was characterized and analyzed through scanning electron microscope (SEM) and transmission electron microscope (TEM). The chemical structure and the crystal structure were explored by X-ray powder diffraction (XPS), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction spectra (XRD). The magnetic property was obtained by vibrating sample magnetometer (VSM). The specific surface area and the average pore size were determined by Brunauer-Emmett-Teller (BET) and Barrett–Joyner–Halenda (BJH). The specific surface and the average pore size of 3D-GO/PVA/Fe 3 O 4 nanocomposites were 388.87 m 2 g -1 and 9.6 nm, and the higher specific surface indicated that the three-dimensional structure avoided the aggregation for GO sheets. The large saturation magnetization (M s ) of the nanocomposites of 30.5 emu/g enabled the easy cycling of the nanocomposites. The 3D-GO/PVA/Fe 3 O 4 nanocomposites exhibited better performance for porcine pancreatic lipase (PPL) enzyme immobilization. The maximum immobilization efficiency was 91%, and the enzyme immobilized 3D-GO/PVA/Fe 3 O 4 nanocomposites reached up to 90% of their activities. After 10 cycles of reuse, the activity of immobilized enzyme remained about 70.8% of the initial activity. The stability test revealed that the activity of immobilized enzyme remained up to 71.1% at 4 °C for 56 days.
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GREEN CHEMISTRY
·
2018
·Vol. 20
·期 10
·2382-2391
·
IF 8.586
Feng Sha,Yucong Zheng,Jiao Chen,Kequan Chen,Fei Cao,Ming Yan,Pingkai Ouyang
In this study, the bio-oxidation of galactitol to the valuable D-tagatose is presented. This proposed strategy could start with the refined by-product of waste xylose mother liquor formed by chemical hydrogenation. Through a computationally guided enzyme screening approach, a robust polyol dehydrogenase (PdPDH) was rapidly identified from a massive number of candidates. When coupled with a water-forming NADH oxidase (StNOX) for environmentally benign cofactor regeneration, subsequent reaction optimization facilitated the complete transformation of 100 g L−1 galactitol into the desired product within 15 h, with a yield of 91% in a 2 L scale preparative reaction. Compared to the current enzymatic isomerization system, our approach avoids low conversion, high operative temperatures and by-product formation, while enabling simplified product isolation.
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JOURNAL OF MOLECULAR LIQUIDS
·
2018
·
IF 4.513
Kemeng Shi,Christian Marcus Pedersen,Zhaohui Guo,Yanqiu Li,Hongyan Zheng,Yan Qiao,Tuoping Hu,Yingxiong Wang
The tautomer distributions of d ‑fructose, a popular model compound for biorefinery , in various lower alcohols and DMSO‑ d 6 (ROHs/DMSO‑ d 6 ) mixtures at 298 K were investigated by quantitative 13 C NMR. The tautomer distributions of d ‑fructose in ethanol/DMSO‑ d 6 and methanol/DMSO‑ d 6 with different volume ratios of alcohols to DMSO‑ d 6 were also examined. For these normal alcohols (methanol, ethanol, n ‑propanol and n ‑butanol)/DMSO‑ d 6 , the tautomer distribution of d ‑fructose in methanol/DMSO‑ d 6 exhibited the shortest equilibration time (46 h) and the lowest concentration of β‑furanose (39.0%) at equilibrium. The fraction of fructofuranose (α‑furanose and β‑furanose) at equilibrium and time needed to reach equilibrium in branched chain alcohols/DMSO‑ d 6 obey the following order: 2‑propanol/DMSO‑ d 6 (62.2%, 320 h) > tert ‑butanol/DMSO‑ d 6 (61.6%, 307 h) > 2‑butanol/DMSO‑ d 6 (60.6%, 216 h) > isobutanol/DMSO‑ d 6 (57.8%, 134 h). For the diols/DMSO‑ d 6 , the time for the tautomer distribution of d ‑fructose to reach the equilibrium was found to be: 1,4‑butanediol/DMSO‑ d 6 (113 h) > 1,2‑propanediol/DMSO‑ d 6 (38 h) > ethylene glycol/DMSO‑ d 6 (36 h). For ethanol/DMSO‑ d 6 and methanol/DMSO‑ d 6 with respectively different volume ratios, the experimental results showed that the high concentration of ethanol or methanol increases the conversion rate of tautomers.
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PHARMACEUTICAL BIOLOGY
·
2018
·
IF 1.918
Wenlong Yang,Guanlin Zhou,Shubing Zou,Wentao Yang,Aihong Liu,Shuilin Sun,Baogang Xie
Context: d-Glucaro-1,4-lactone (1,4-GL) exists in many vegetables and fruits. Metabonomics has not been used to investigate the role of 1,4-GL in preventing liver cancer.Objective: The pharmacological effects and metabolite alterations of 1,4-GL on the prevention of diethylnitrosamine (DEN)-induced liver cancer were investigated.Materials and methods: Ten healthy Sprague–Dawley rats served as control and 46 were used to establish rat liver cancer model. 1HNMR-based metabonomics was used to compare the effects of oral 1,4-GL (50 mg/kg) in liver cancer rats (n = 26) after 10 consecutive weeks of intervention. The amino acids in rat serum were quantified by HPLC-UV, and the changes in Fischer’s ratio were calculated.Results: The 20-week survival rate of DEN-induced liver cancer rats administered with oral 1,4-GL was increased from 45.0 to 70.0% with reduced carcinogenesis of the liver and significantly lowered serum α-fetoprotein level (14.28 ± 2.89 ng/mL vs. 18.56 ± 4.65 ng/mL, p = 0.012). The serum levels of leucine, valine, 3-hydroxybutyrate, lactate, acetate and glutamine in the DEN + 1,4-GL group returned to normal levels compared with those of the DEN group on week 20. Fischer’s ratio in the rat serum of DEN group was 1.62 ± 0.21, which was significantly lower than that in healthy rats (2.3 ± 0.12). However, Fischer’s ratio increased to 1.89 ± 0.22 in the DEN + 1,4-GL group.Discussion and conclusions: 1,4-GL exerted positive effects on liver carcinogenesis in rats by pathological examination and metabonomic analysis. Its mechanism may be related to the restoration of amino acid and energy metabolism.
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