查找使用阿拉丁产品的科研文献

Suppression mechanism of L-lysine on the Epigallocatechin-3-gallate-induced loss of myofibrillar protein gelling potential

Mengyuan Wang,Jingchao Kang,Lin Chen,Gongchen He,Yaping Liu,Xiaojing Fan,Xin Lv,Xinglian Xu,Guanghong Zhou,Xianchao Feng

As a natural antioxidant, Epigallocatechin-3-gallate (EGCG) needed to be added in high doses to maintain the quality of meat products. However, high doses of EGCG caused the excessive aggregation of myofibrillar protein (MP), which damaged the gel properties of MP gels. Therefore, the purpose of this study was to investigate the mitigation of EGCG-induced loss of MP gelling potential by L-Lysine (L-Lys). The results showed that the addition of 20 mM L-Lys induced excessive unfolding and loose aggregation of MP at 10 µmol/g EGCG, and hence, reducing the solubility (14.5%) and the tryptophan fluorescence, and forming a network structure with a large aperture. Therefore, the cooking loss was decreased from 29.20% to 15.13%, and the strength of MP gels was decreased from 0.35 N to 0.17 N. However, L-Lys hindered the hydrogen bonding interactions and hydrophobic interactions between MP and EGCG by competing the binding sites of MP at 50 µmol/g EGCG, which was supported by the Zeta potential, surface hydrophobicity, FTIR and molecular docking analysis. Thus L-Lys mitigated the protein aggregation caused by 50 µmol/g EGCG, improved the solubility (23.02%∼86.99%) and apparent viscosity, which were beneficial for the formation of a continuous network structure in MP gels. Therefore, the cooking loss of MP gels was decreased from 52.40% to 41.30%, and the gel strength was enhanced from 0.13 N to o.22 N with 20 mM L-Lys addition. The present study could provide a new strategy for increasing the amounts of EGCG in meat products without damaging the gel properties of meat products.

Co-Delivery of paclitaxel and doxorubicin in folate-Targeted pluronic/ploy (D,L-lactide-b-glycolide) polymersomes

Tian Yi Wu,Wen Jie Cao,Zi Ling Li,Yan Chun Gong,Xiang Yuan Xiong

Drugs with different solubility can be selectively embedded into polymersomes with the hydrophilic core and hydrophobic bilayer. Novel folate-targeted Pluronic/poly (D,L-lactide-b-glycolide) polymersomes were constructed and used for the co-delivery of paclitaxel (PTX) and doxorubicin (DOX) to improve their inhibitory effect over cancer cells. The particle size of blank polymersomes was mainly distributed below 125 nm. The release of PTX and DOX from polymersomes showed an initial burst release followed by a sustained and slow release. The in vitro cytotoxicity data showed that the targeted co-loaded polymersomes (PTX&DOX FA-Ps) exhibited better inhibitory effect than single-loaded polymersomes and free drugs did. Furthermore, PTX&DOX FA-Ps showed the synergistic therapeutic effect over OVCAR-3 cancer cells. The cellular uptake results also showed that folate modified polymersomes had excellent targeting performance. Therefore, the folate-targeted Pluronic/poly (D,L-lactide-b-glycolide) polymersomes have potential application value as novel drug carriers to co-deliver PTX and DOX.

L-Arginine enhanced perylenequinone production in the endophytic fungus Shiraia sp. Slf14(w) via NO signaling pathway

Chen Yunni,Xu Chenglong,Yang Huilin,Liu Zhenying,Zhang Zhibin,Yan Riming,Zhu Du

Abstract Perylenequinones (PQ) are natural polyketides used as anti-microbial, -cancers, and -viral photodynamic therapy agents. Herein, the effects of L-arginine (Arg) on PQ biosynthesis of Shiraia sp. Slf14(w) and the underlying molecular mechanism were investigated. The total content of PQ reached 817.64 ± 72.53 mg/L under optimal conditions of Arg addition, indicating a 30.52-fold improvement over controls. Comparative transcriptome analysis demonstrated that Arg supplement promoted PQ precursors biosynthesis of Slf14(w) by upregulating the expression of critical genes associated with the glycolysis pathway, and acetyl-CoA and malonyl-CoA synthesis. By downregulating the expression of genes related to the glyoxylate cycle pathway and succinate dehydrogenase, more acetyl-CoA flow into the formation of PQ. Arg supplement upregulated the putative biosynthetic gene clusters for PQ and activated the transporter proteins (MFS and ABC) for exudation of PQ. Further studies showed that Arg increased the gene transcription levels of nitric oxide synthase (NOS) and nitrate reductase (NR), and activated NOS and NR, thus promoting the formation of nitric oxide (NO). A supplement of NO donor sodium nitroprusside (SNP) also confirmed that NO triggered promoted biosynthesis and efflux of PQ. PQ production stimulated by Arg or/and SNP can be significantly inhibited upon the addition of NO scavenger carboxy-PTIO, NOS inhibitor N ω -nitro-L-arginine, or soluble guanylate cyclase inhibitor NS-2028. These results showed that Arg-derived NO, as a signaling molecule, is involved in the biosynthesis and regulation of PQ in Slf14(W) through the NO-cGMP-PKG signaling pathway. Our results provide a valuable strategy for large-scale PQ production and contribute to further understanding of NO signaling in the fungal metabolite biosynthesis. Key points • PQ production of Shiraia sp. Slf14(w) was significantly improved by L-arginine addition. • Arginine-derived NO was firstly reported to be involved in the biosynthesis and regulation of PQ. • The NO-cGMP-PKG signaling pathway was proposed for the first time to participate in PQ biosynthesis.

De novo transcriptome analysis of Cnidium monnieri (L.) Cuss and detection of genes related to coumarin biosynthesis

Yuanyuan Shi,Shengxiang Zhang,Daiyin Peng,Chunmiao Shan,Liqiang Zhao,Bin Wang,Jiawen Wu

Cnidium monnieri (L.) Cuss ( C. monnieri ) is one of the most widely used traditional herbal medicines, exhibiting a wide range of pharmacological functions for treating asynodia, trichomonas vaginitis, and osphyalgia. Its important medicinal value comes from its abundance of coumarins. To identify genes involved in coumarin biosynthesis and accumulation, we analyzed transcriptome data from flower, leaf, root and stem tissues of C. monnieri . A total of 173,938 unigenes with a mean length of 1,272 bp, GC content of 38.79%, and N50 length of 2,121 bp were assembled using the Trinity program. Of these, 119,177 unigenes were annotated in public databases. We identified differentially expressed genes (DEGs) based on expression profile analysis. These DEGs exhibited higher expression levels in flower tissue than in leaf, stem or root tissues. We identified and analyzed numerous genes encoding enzymes involved in coumarin biosynthesis, and verified genes encoding key enzymes using quantitative real-time PCR. Our transcriptome data will make great contributions to research on C. monnieri and provide clues for identifying candidate genes involved in coumarin metabolic pathways.

Tolerant mechanism of Jatropha curcas L. roots to acid rain in soils with different acid-buffering capacities

Shu Xiao,Zhang KeRong,Zhang QuanFa,Wang WeiBo

Acid rain remains a global environmental issue that can indirectly impact plant root growth and health by mediating soil acidification. The impact of acid rain on the roots of Jatropha curcas L., however, has not been thoroughly evaluated to date in soils with a range of buffering capacities. We, therefore, explored the ability of J. curcas roots to tolerate acid rain in a range of soil types by exposing samples to simulated acid rain (SAR) (pH2.5, pH3.5, pH4.5, pH5.6) and then examining the impact of such exposure on root morphology, relative growth rate (RGR root ), nutrient absorption, enzymatic activity, and microbial biomass. Yellow–brown soil (YBS) and purple soil (PS) were found to be better able to buffer SAR-mediated acidification, thereby providing superior benefits to J. curcas root growth as compared to red soil (RS) and yellow soil (YS) under these experimental conditions. SAR (pH 4.5) significantly enhanced Ca, K, and Mg absorption by J. curcas roots, thereby improving their growth characteristics, whereas SAR (pH 2.5) impaired K and Mg absorption and thus suppressed root growth. K and Mg absorption characteristics were regulated by changes in plasma membrane H + -ATPase activity under these different SAR treatment conditions. Morphological and growth (RGR root ) adaptations of J. curcas roots to SAR treatment were associated with superoxide dismutase activity levels therein. SAR (pH 4.5) was sufficient to bolster the rhizosphere microbial activity of J. curcas seedlings, and correlation analyses revealed that root growth was regulated by rhizosphere microbial biomass P content under SAR treatment conditions.

Enrichment and Purification of the Bioactive Flavonoids from Flower of Abelmoschus manihot (L.) Medic Using Macroporous Resins

Zhenzhong Yang,Haitao Tang,Qing Shao,Anna Rita Bilia,Yi Wang,Xiaoping Zhao

Flower ofAbelmoschus manihot(FAM) is clinically effective to treat chronic kidney disease (CKD) with a relatively high dosage. To improve the efficacy and the compliance of patients, macroporous resins were adopted to enrich and purify flavonoids from FAM, which are thought to be the major renal protective constituents in FAM. After screening six different kinds of macroporous resins, HPD-100 was selected for its great adsorption and desorption capacity. Then, orthogonal design tests were used to optimize parameters in the processes of impurity removal and flavonoids of FAM desorption on column chromatogram. Moreover, process scale-up was performed, and purification effects maintained after amplification. After purification, the content of seven main flavonoids in the product increased from 8.29% to 51.43%. Protective and anti-inflammatory effects of crude extract and the flavonoid component of FAM after purification were investigated on the adriamycin-damaged HK-2 cells and lipopolysaccharide-stimulated Raw 264.7 cells models. Both bioactivities were improved greatly after purification for these two cell models. Therefore, the purification process had enriched the main bioactive constituents with potential alleviating kidney injury activities. The flavonoid component of FAM is worthy of being developed as an improved remedy for CKD with better patients’ compliance.Keywords:Abelmoschus manihotflowers;macroporous resins;flavonoids

Investigation of silk fibroin nanoparticle-decorated poly(l-lactic acid) composite scaffolds for osteoblast growth and differentiation

Biao-Qi Chen,Ranjith Kumar Kankala,Ai-Zheng Chen,Ding-Zhu Yang,Xiao-Xia Cheng,Ni-Na Jiang,Kai Zhu,Shi-Bin Wang

Self-assembly of L-cysteine–gold nanoparticles as chiral probes for visual recognition of 3,4-dihydroxyphenylalanine enantiomers

Lin Zhang,Chunli Xu,Guoxin Song,Baoxin Li

A simple protocol to distinguish enantiomers is extremely intriguing and useful. Herein, we report on a method for the visual recognition of 3,4-dihydroxyphenylalanine (Dopa) enantiomers. It is based on the chirality of L-cysteine-capped gold nanoparticles (L-Cys-capped AuNPs) that can be used as a chiral selector for L- and D- forms of Dopa. On addition of L-Dopa to a solution of the L-Cys-capped AuNPs, a color change from red to blue can be seen, while no color change is found on addition of D-Dopa. The chiral recognition can be achieved by eye and simple spectrophotometry. Notably, this method does not require complicated chiral modification. The method excels through its low-cost, good availability of materials, and its simplicity.

Isolation and Characterization of Nanocellulose with a Novel Shape from Walnut (Juglans Regia L.) Shell Agricultural Waste

Dingyuan Zheng,Yangyang Zhang,Yunfeng Guo,Jinquan Yue

Herein, walnut shell (WS) was utilized as the raw material for the production of purified cellulose. The production technique involves multiple treatments, including alkaline treatment and bleaching. Furthermore, two nanocellulose materials were derived from WS by 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) oxidation and sulfuric acid hydrolysis, demonstrating the broad applicability and value of walnuts. The micromorphologies, crystalline structures, chemical functional groups, and thermal stabilities of the nanocellulose obtained via TEMPO oxidation and sulfuric acid hydrolysis (TNC and SNC, respectively) were comprehensively characterized. The TNC exhibited an irregular block structure, whereas the SNC was rectangular in shape, with a length of 55–82 nm and a width of 49–81 nm. These observations are expected to provide insight into the potential of utilizing WSs as the raw material for preparing nanocellulose, which could address the problems of the low-valued utilization of walnuts and pollution because of unused WSs.Keywords:Walnut shell;nanocellulose;TEMPO oxidation;sulfuric acid hydrolysis;ultrasonication

A new finding of reverse three-component thermochromic pigments using biomass-derived l-ascorbyl palmitate color developer

Jiayin Liu,Yunjie Yin,Juanjuan Sun,Weidong Yu,Jialing Tan,Chaoxia Wang

The fatty alcohol phase change material is used as the solvent for three-component thermochromic pigment (the leuco dye-color developer-solvent), which has the dual functions of both thermochromism and thermal energy storage. However, bisphenol A is usually used as the color developer of the three-component thermochromic pigments currently, which has potential safety hazards and is not conducive to market promotion. For most three-component thermochromic pigments, their colors change from colored to colorless. Here, we prepare the biomass-derived thermochromic pigment (TC-LAP) by using l -ascorbate palmitate (LAP) as a color developer, crystalline violet lactone (CVL) as a leuco dye, and tetradecanol (TD) as a solvent. Interestingly, a special reverse thermochromic phenomenon of endothermic color deepening is found. Heating causes the discoloration of TC-LAP from colorless to colored. Thermal energy storage and reverse thermochromic are realized and devoid of safety hazards. The color of TC-LAP thermochromic pigment changes from white to blue with heating, and the CIE 1931 chroma coordinates change from X = 0.21, Y = 0.26 to X = 0.36, Y = 0.36. For the TC-LAP thermochromic pigment, the chromaticity coordinates of blue (X = 0.36, Y = 0.36) correspond to the energy storage of 179.91 J/g and the discoloration temperature of 40 °C. Reverse thermochromism is an exciting discovery for the color diversity of low temperature and controlled three-component thermochromic pigment. Meanwhile, the use of biomass-derived LAP also alleviates the safety hazard of BPA color developer in three-component thermochromic pigment.

A novel electrochemical sensor based on Fe2O3 nanoparticles/N-doped graphene for electrocatalytic oxidation of L-cysteine

Yang Suling,Li Gang,Wang Guifang,Deng Dehua,Qu Lingbo

A novel electrochemical sensor based on Fe 2 O 3 nanoparticles supported on N-doped graphene (Fe 2 O 3 NPs/N–GR) has been fabricated for electrocatalytic oxidation and detection of L-cysteine. The Fe 2 O 3 NPs/N–GR was characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy (XPS), and electrochemical methods. The electrochemical behavior of L-cysteine at Fe 2 O 3 NPs/N–GR was investigated by voltammetry. The Fe 2 O 3 NPs/N–GR showed a very efficient electrocatalytic activity for the oxidation of L-cysteine in 0.1 M phosphate buffer solution (PBS, pH 7.0). The oxidation peak currents increased dramatically at Fe 2 O 3 NPs/N–GR-modified electrode. The potential utility of the sensor was demonstrated by applying it to the analytical determination of L-cysteine. Experimental results showed that the electrocatalytic current increased linearly with L-cysteine concentration in the range of 0.2–400 μM with a lowest detectable concentration of 0.1 μM.

Ambient Hydrogen Storage and Release Using CO2 and an l-Arginine-Functionalized PdAu Catalyst via pH Control

Shuchao Jiang,Junxia Yang,Shengliang Zhai,Ling Zhang,Rui Tu,Tie Yu,Dong Zhai,Lei Sun,Weiqiao Deng,Guoqing Ren

Formic acid (FA)/formate as a promising liquid organic hydrogen carrier exhibits great potential for future energy supplies. However, FA/formate-based hydrogen storage and release, which can be operated under ambient conditions, is challenging but attractive. Here, we report an ambient hydrogen storage and release process that uses the acidity and alkalinity of the reaction solution to control hydrogen production or consumption via an l-arginine-functionalized active carbon-supported PdAu alloy catalyst (PdAu/AC-LA). By regulating the LA loading and Pd/Au ratio, we obtain the optimal catalytic activity with turnover frequency (TOF) of 1760 h–1 for FA dehydrogenation under acidic conditions and 138 h–1 for CO2 hydrogenation under alkaline conditions. Comprehensive characterizations, including X-ray photoelectron spectroscopy (XPS), CO2 temperature-programmed desorption (CO2-TPD), and HCOO– adsorption experiments, reveal that the synergistic effect between PdAu alloy and strongly basic l-arginine enhances catalytic activity by regulating the adsorption of reactants. Our work, as a successful example of FA/formate-based hydrogen storage and release under ambient conditions, may aid putting the safe and energy-saving use of hydrogen into practice.