EUROPEAN POLYMER JOURNAL
·
2012
·
IF 2.739
Qingye Liu,Xiaojuan Xu,Lina Zhang,Junping Yu
The interaction between polydeoxyadenylic acid (poly(dA)) and single chains of Lentinan (s-LNT) was investigated by circular dichroism spectra (CD), UV–Vis spectra, nano-differential scanning calorimetry (nano-DSC), dynamic light scattering (DLS), and atomic force microscopy (AFM). All the experimental results indicated that poly(dA) really interacted with s-LNT having molecular weight of 5.3 × 10 5 to form a novel composite with stiff conformation through hydrogen bonding , whereas the triple helical Lentinan (t-LNT) could not, implying that it was the single chain but not the triple helical chain interacted with poly(dA). Meanwhile, the interaction strongly depended on the concentration of s-LNT and pH. When the poly(dA) concentration was fixed at 5.3 μg/ml, the interaction between poly(dA) and s-LNT increased with an increase in s-LNT concentration, then reached the maximum at ∼60 μg/ml, finally decreased with further increase of s-LNT concentration. This was due to self-renaturation of s-LNT into triple helix or incomplete species confirmed by nano-DSC. The poly(dA)/s-LNT complex could exist in solutions with pH 5.5–11.5, and pH 7–10 was the optimal condition for the complex, showing higher stability against pH than the positive control of poly(dA)/s-SPG. The dynamic behaviors of the complex demonstrated that the interaction between s-LNT and poly(dA) occurred rapidly, and reached stable within 3–7 h. Moreover, the thermal stability of poly(dA) was enhanced by complexation with s-LNT. The topograph of the poly(dA)/s-LNT complex was shown as rod-like stiff architecture. This work enlarges the application of LNT in the biomedical field.
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Microbial Cell Factories
·
2016
·Vol. 15
·期 1
·1-9
·
IF 3.744
Yang Jianming,Nie Qingjuan
Background Under aerobic conditions, acetic acid is the major byproduct produced by E. coli during the fermentation. And acetic acid is detrimental to cell growth as it destroys transmembrane pH gradients. Hence, how to reduce the production of acetic acid and how to utilize it as a feedstock are of intriguing interest. In this study, we provided an evidence to produce β-caryophyllene by the engineered E. coli using acetic acid as the only carbon source. Results Firstly, to construct the robust acetate-utilizing strain, acetyl-CoA synthases from three different sources were introduced and screened in the E. coli . Secondly, to establish the engineered strains converting acetic acid to β-caryophyllene, acetyl-CoA synthase (ACS), β-caryophyllene synthase (QHS1) and geranyl diphosphate synthase (GPPS2) were co-expressed in the E. coli cells. Thirdly, to further enhance β-caryophyllene production from acetic acid, the heterologous MVA pathway was introduced into the cells. What’s more, acetoacetyl-CoA synthase (AACS) was also expressed in the cells to increase the precursor acetoacetyl-CoA and accordingly resulted in the increase of β-caryophyllene. The final genetically modified strain, YJM67, could accumulate the production of biomass and β-caryophyllene up to 12.6 and 1.05 g/L during 72 h, respectively, with a specific productivity of 1.15 mg h −1 g −1 dry cells, and the conversion efficiency of acetic acid to β-caryophyllene (gram to gram) reached 2.1 %. The yield of β-caryophyllene on acetic acid of this strain also reached approximately 5.6 % of the theoretical yield. Conclusions In the present study, a novel biosynthetic pathway for β-caryophyllene has been investigated by means of conversion of acetic acid to β-caryophyllene using an engineered Escherichia coli . This was the first successful attempt in β-caryophyllene production by E. coli using acetic acid as the only carbon source. Therefore, we have provided a new metabolic engineering tool for β-caryophyllene synthesis.
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JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2017
·Vol. 130
·期 2
·773-780
·
IF 1.953
Zhang Zishou,Li Mei,Wu Lijun,Zhang Yangfan,Mai Kancheng
Aluminum hydroxide-filled polypropylene composites generally form α-crystal due to the strong heterogenous α-nucleation of filler. In order to utilize β-crystal PP with high toughness to prepare aluminum hydroxide-filled PP composites, the aluminum hydroxide-filled PP composites nucleated by calcium pimelate and PP composites filled by calcium pimelate-supported aluminum hydroxide were fabricated. The crystallization and melting behavior of filled composites were compared by differential scanning calorimetry. The influence of aluminum hydroxide contents on the β-crystal content in the filled PP composites was discussed. It is a novel effective method to prepare aluminum hydroxide-filled β-PP composites with calcium pimelate-nucleated aluminum hydroxide.
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NEW JOURNAL OF CHEMISTRY
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2016
·Vol. 40
·期 3
·1982-1987
·
IF 3.277
Chen Chen,Jun Lv,Wanyi Chen,Yang Xiang,Juan Zhang
A colorimetric method is developed for the determination of the activity of β-lactamase (β-Lac) and the screening of its inhibitors based on cysteine-induced gold nanoparticle (AuNP) aggregation. The widely used penicillin is served as a β-Lac substrate, and the strong reduction capability of its corresponding product, which can react with Cu(II) to form Cu(I) conjugates, is utilized in the method. The double catalyzed signal amplification is accomplished via the addition of both β-Lac and Cu(II) which can catalyze the oxidization of cysteine into cystine. The activity of β-Lac is determined at levels as low as 2.36 U mL−1. The inhibitory effects of clavulanic acid and sulbactam are tested and give 0.92 and 0.06 μM, respectively. The assay is simple, rapid, easy-operated, and selective, and the proposed method has a great potential not only for the detection of β-Lac activity but also for the screening of the inhibitors.
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Materials Science & Engineering C-Materials for Biological Applications
·
2016
·
IF 3.42
Zejun Xu,Yi Zhang,Qian Hu,Qiao Tang,Jiake Xu,Jianping Wu,Thomas Brett Kirk,Dong Ma,Wei Xue
The development of biocompatible vector for hydrophobic drug delivery remains a longstanding issue in cancer therapy. We design and synthesis a drug delivery system based on HPG modified β -CD ( β -CD-HPG) by conjugating HPG branches onto β -CD core and its structure was confirmed by NMR, FTIR, GPC and solubility. In vitro biocompatibility tests showed that HPG modification significantly improved red blood cells morphology alteration and hemolysis cause by β -CD and β -CD-HPG displayed cell safety apparently in a wide range of 0.01–1 mg/mL. An anti-cancer drug, docetaxel, was effectively encapsulated into β -CD-HPG which was confirmed by DSC analysis. This copolymer could form nanoparticles with small size (< 200 nm) and exhibited better DTX loading capacity and controlled release kinetics without initial burst release behavior compared with β -CD. Furthermore, antitumor assay in vitro show that β -CD-HPG/DTX effectively inhibited proliferation of human breast adenocarcinoma cells. Therefore, β -CD-HPG/DTX exhibit great potential for cancer chemotherapy.
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THERMOCHIMICA ACTA
·
2013
·
IF 1.989
Haisu Gao,Liping Chen,Wanghua Chen,Shilong Bao
The thermal stability of β-artemether under dynamic, isothermal and adiabatic conditions were investigated by differential scanning calorimeter (DSC) and accelerating rate calorimeter (ARC), respectively. The dynamic DSC measurements at various heating rates (1, 2, 4 and 8 °C min −1 ) displayed that β-artemether experienced polymorph transformation in the melting process. According to the isothermal DSC results at different temperatures 86, 88, 90 and 92 °C, β-artemether decomposed after the completion of the melting and the polymorph transformation, and the thermal decomposition of β-artemether is hazardous for its characteristic of autocatalytic decomposition. The kinetics analysis dynamically and isothermally described by Friedman method indicated the thermal decomposition of β-artemether did not comply with a single mechanism. The ARC results showed that the pressure increased with the increase of temperature, and indicated obvious linear relationship. Based on the ARC data, the value of SADT of β-artemether in 50 kg package was obtained.
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CHIRALITY
·
2013
·Vol. 25
·期 10
·656-662
·
IF 1.894
Yangmin Ma,Hao Wu,Jin Zhang,Yanchao Li
A series of single isomers tetrahydro- β -carboline diketopiperazines were stereoselectively synthesized starting from l -tryptophan methyl ester hydrochloride and six aldehydes through a four-step reaction including Pictet-Spengler reaction, crystallization-induced asymmetric transformations (CIAT), Schotten-Baumann reaction, and intramolecular ester amidation. The chemical structures were characterized by nuclear magnetic resonance (NMR) and elemental analysis, among which two compounds were determined by x-ray single crystal diffraction. Moreover, antimicrobial activities of all the compounds were also tested. Chirality 25:656–662, 2013 . © 2013 Wiley Periodicals, Inc.
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RSC Advances
·
2015
·Vol. 5
·期 63
·51364-51370
·
IF 3.84
Zongxue Yu,Yang Pan,Yi He,Guangyong Zeng,Heng Shi,Haihui Di
As part of this work, polyvinylidene fluoride (PVDF) membranes were prepared via a phase inversion method. A novel β-cyclodextrin (β-CD)–PVDF membrane was prepared via an interfacial reaction, using Trimesoyl Chloride (TMC) and β-CD as cross-linking and modification agents, respectively. The membranes were modified by a simple dip-coating method. The results of comparison between the modified and unmodified membranes by attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR) and X-ray photoelectron spectroscopy (XPS) methods confirmed successful grafting of β-CD on the membrane surfaces. The morphology of the membrane was investigated by scanning electron microscopy (SEM) and atomic-force microscopy (AFM). The roughness of PVDF membranes increased after their surfaces were grafted with β-CD. It was also found that β-CD–PVDF membranes had higher permeate flux and hydrophilicity than those of the pristine PVDF membranes. Furthermore, in protein fouling experiments, bovine serum albumin (BSA) was used as a protein model solution. Modified membranes exhibited a higher flux recovery ratio. The experiment showed that the anti-fouling performance of β-CD–PVDF membranes was more effective in reducing the irreversible membrane fouling. The results of this study hold promise for useful applications of β-CD–PVDF membranes in membrane separation areas.
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DESALINATION
·
2024
·
IF 8.3
Jian Yu,Ling Zhang,Hongguang Sun,Renjie Li,Die Ling Zhao,Liguo Shen,Hongjun Lin,Yang Jiao,Yanchao Xu
The use of sacrificial layers on porous substrates has proven to be an effective approach for regulating the interfacial polymerization process and shaping the structure of polyamide (PA) nanofiltration (NF) membranes, thereby addressing the trade-off between permeability and selectivity. However, the synthesis and removal of traditional interlayer materials often require harsh chemicals, generating hazardous waste and posing environmental risks. In this study, we utilized green, non-toxic, and biodegradable β-cyclodextrin (β-CD) nanosheets as an interlayer in the interfacial polymerization process. These nanosheets were subsequently dissolved in water to create crumpled polyamide nanofiltration membranes, avoiding the use of toxic chemicals and significantly reducing environmental impact. With an optimal β-CD loading of 1.0 mg/cm 2 , the resulting membrane exhibited a remarkable water flux of 13.4 LMH/bar, reflecting a 330 % improvement over the reference membrane, along with a 97.9 % Na₂SO₄ rejection. This performance enhancement is linked to enhanced surface hydrophilicity, a higher surface charge density, and a thinner PA layer with an expanded surface area. The membrane also exhibited excellent antifouling properties and long-term separation performance. This innovative, eco-friendly approach represents a significant advancement in membrane technology, providing a sustainable solution for enhanced nanofiltration membrane performance in water treatment applications.
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APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Jing Qi,Jichang Tu,Xian Xie,Hongling Wang,Ruiqi Xie
In view of the combination of dodecylamine and hydroxamate can improve the flotation recovery of spodumene, a novel β -amino-hydroxamate surfactant, i.e., N -(3-(dodecylamino)) hydroxamic acid (DAHA), was designed and introduced into spodumene flotation. The micro-flotation performance indicated that DAHA performed excellent collecting ability toward spodumene, and 2.0 × 10 -4 mol/L of DAHA floated out about 90.2% of spodumene, while that of sodium oleate (NaOL) was only about 57.4%. The zeta potential of DAHA-treated spodumene revealed the effective chemisorption of hydroxamate group on spodumene surface. FTIR and XPS recommended that the hydroxamate group in DAHA chelated with surface Al sites to form five-membered hydroxamate-(O,O)-Al complexes. The affinity of DAHA on spodumene spontaneously enhanced by the protonated amino group (–NH 3 + ), which facilitated the chelation of hydroxamate with the surface Al atoms and strengthened the hydrophobicity of spodumene.
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BMC Veterinary Research
·
2024
·Vol. 20
·期 1
·1-11
·
IF 2.3
Ding Yili,Zhang Zhiyuan,Ding Charles,Xu Shufeng,Xu Zhe
As an orally effective benzimidazole anthelmintic agent, fenbendazole was not only widely used in agriculture and animal husbandry to prevent and treat parasites, but also shows anti-cancer effects against several types of cancer, exhibits anti-cancer effects in paclitaxel and doxorubicin-resistant cancer cells. However, fenbendazole’s poor in water solubility (0.3 µg/mL), limits its clinical applications. Even great efforts were made toward increasing its water solubility, the results were not significant to reach anti-cancer drug delivery requirement (5–10 mg/mL). Through single factor and orthogonal strategy, many complex conditions were designed and used to prepare the complexes, the inclusion complex with methyl- β -cyclodextrin with 29.2 % of inclusion rate and 89.5% of inclusion yield can increase drug’s water solubility to 20.21 mg/mL, which is the best result so far. Its structure was confirmed by differential scanning calorimetry, scanning electron microscopic image, 1D and 2D NMR spectra in D 2 O. In its in vitro pharmacokinetic study, fenbendazole was 75% released in 15 min., in its in vivo pharmacokinetic study, the bio-availabilities of fenbendazole, its major metabolic anthelmintic agent oxfendazole and its minor metabolic anthelmintic agent oxfendazole were increased to 138%, 149% and 169% respectively, which would allow for fewer drug doses to achieve the same therapeutic effect and suggest that the complex can be used as a potential anticancer agent.
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Scientific Reports
·
2025
·Vol. 15
·期 1
·1-11
·
IF 3.9
Yu Xiang-Fang,Gurung Chetali,Yu Zhongjia,Xiao Wei,Kerem Goher,Teng Bin,Zhang Jian V.,Su Zhe,Zhou Yongjin,Ren Pei-Gen
Awareness of the intestinal microflora involved in insulin resistance and type 2 diabetes (T2DM) has now become more evident. However, direct mechanical insight is required to illustrate the contribution of intestinal microflora in the disease progression. In this study, we aimed to precisely assess the changes in intestinal bacteria translocation (IBT) from gut to the pancreas using combinations of FISH, 16S rRNA amplicon sequencing, and deep learning-assisted methods to track IBT in diet-induced obese (DIO) and antibiotic-induced microbiota disruption (AIMD)-DIO mouse models. Our analysis showed deep learning-assisted quantification enhanced the accuracy and objectivity of bacterial tracking. The DIO mice exhibited increased IBT, likely due to excessive intestinal lipid accumulation and compromised intestinal barrier integrity. Elevated bacterial loads in the pancreas were associated with worsened pancreatic function, indicated by higher fasting blood glucose, impaired glucose tolerance, and dysfunctional insulin secretion. In contrast, the AIMD-DIO group lowered the IBT, maintained the islet structure and improved glucose homeostasis. Comparative study between DIO and AIMD-DIO models revealed a strong correlation between number of translocated bacteria and T2DM severity. These findings provide objective evidence of bacterial migration from the intestine to the pancreas and establishes its pathological relationship with pancreatic impairment and dysfunction and underscores to utilize AI techniques more successfully in the future for evaluating IBT.
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