African Journal of Pharmacy and Pharmacology
·
2017
·Vol. 12
·期 47
·582-590
·
IF 0
Raphael N. Alolga,Enos Mais,Vitus Onoja
The quality of botanicals has been reported to be influenced by their places of cultivation. Although, ginger remains a common health remedy both in Ghana and China, no comparative study exists to the best of the authors’ knowledge, on the anti-inflammatory properties of ginger from these two countries. The aim of this study was to comparatively assess the anti-inflammatory effect of the methanolic extracts of fresh ginger samples from Ghana and China and identify biomarker(s) that is/are diagnostic of acute inflammation via untargeted metabolomics. A phytochemical assessment of the ginger extracts was initially performed with high performance liquid chromatography- quadrupole time-of-flight mass spectrometry (HPLC-Q/TOF-MS). Low (200 mg/kg) and maximum (400 mg/kg) doses the ginger extracts from each country were assessed using Sprague-Dawley (SD) rats against groups for positive (indomethacin, 10 mg/kg) and negative controls (no drug). Blood samples were taken from the retro orbital vein at four time points: 1, 4, 8 and 24 h after induction of inflammation. The levels of tumor necrosis factor-α (TNF-α) and prostaglandin E2 (PGE2) were determined in the plasma samples. The metabolomics study was also performed with HPLC-QTOF/MS and the data analyzed with MetaboAnalyst 3.0 and SIMCA 14.1. Phytochemical evaluation revealed marked differences in terms of the compounds deemed to have anti-inflammatory activities in the ginger samples from the two countries. Ginger extract from Ghana showed superior anti-inflammatory effects over that from China. In the metabolomics study, L-valine was identified as the diagnostic biomarker of acute inflammation from 8 differential metabolites identified.
研究领域:
植物学
·
药理学
·
代谢组学
✓ 已验证
DOI
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Jibao Zhang,Yan Li,Zhenyuan Yin,Praveen Linga,Tianbiao He,Xiang Yuan Zheng
Hydrogen (H 2 ) emerges as a promising future clean energy for the low-carbon and sustainable future due to its high energy density and no pollutant or greenhouse gas emissions after combustion. The advantage of H 2 storage in solid-hydrate form is the requirement of only moderate pressure and temperature compared to compressed H 2 storage and the relatively lower energy consumption compared to liquid H 2 storage. However, the slow kinetics of H 2 hydrate formation is one major challenge to breakthrough for the large-scale development of hydrate-based H 2 storage. In this study, we introduced an environmental-benign kinetic promoter ( L -valine, L -Val) and coupled it with a thermodynamic promoter tetrahydrofuran (THF) using stoichiometric concentration (5.56 mol%) to enhance H 2 hydrate formation kinetics. 0.3 wt% L -Val coupled with 5.56 mol% THF yields the optimal kinetic enhancement, and the maximum volumetric H 2 uptake ( V H2 ) is 29.83 ± 1.22 volume of H 2 /volume of H 2 -THF hydrate (v /v). The reusability of L -Val is proved in five consecutive cycles of H 2 -THF hydrate formation and dissociation with consistently superior H 2 uptake. Furthermore, it was identified that cooling rate ( R c ) was an important factor determining the H 2 -THF hydrate formation kinetics. Lower R c (0.05 K/min) shows an optimal promoting effect of V H2 , which was 105.29% higher than that at higher R c (0.3 K/min). A mechanism is proposed to explain the effect of R c on H 2 -THF hydrate formation kinetics. The maximum gravimetric H 2 ( G H2 ) reported in our study reaches 0.26 ± 0.01 wt%, which was superior in current literature below 15.0 MPa. The results provide insights into speeding up H 2 uptake in solid-hydrate form and have potential applications in hydrate-based hydrogen storage.
研究领域:
化学工程
·
能源存储
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CURRENT MICROBIOLOGY
·
2020
·Vol. 77
·期 6
·1016-1023
·
IF 1.746
Yue Xue,Yan Bingyu,Wang Shuai,Gao Wen,Zhang Ruiyan,Dong Huijun
The glycopeptide A40926 biosynthesized by Nonomuraea gerenzanensis is a precursor of the second generation glycopeptide antibiotic dalbavancin. The skeleton of this glycopeptide consists of seven amino acids and is biosynthesized by the NRPS gene module. L-valine, a branched amino acid, is also a significant precursor for A40926 production. This study details the use of pH-responsive alginate–chitosan microspheres loaded with L-valine prepared by internal emulsification gelation. The effects of process and formulation variables on microsphere size, loading capacity, and encapsulation efficiency were investigated. Then, effects on A40926 production by the pH-responsive microspheres were evaluated in a 10-L fermenter. Results demonstrated that use of the pH-responsive microspheres could improve A40926 yield from 465 to 602 mg L −1 in a 10-L scale fermenter.
研究领域:
微生物学
·
生物工程
·
药学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2012
·Vol. 125
·期 4
·3092-3099
·
IF 1.289
Suwen Ye,Licheng Tan,Yiwang Chen,Junchao Wei,Weihua Zhou
A series of aliphatic biodegradable poly(butylene succinate)- co -oligo( L -valine) (PBSVAL) copolyesters were synthesized with dimethyl succinate, 1,4-butanediol (BDO), and oligo( L -valine) (OVL) as reagents. The GPC results show that the weight average molecular weight ( M w ) of the copolyester with a feed ratio (PBS/OVL) of 0.9/0.1 (PBSVAL 10 ) is 4.9 × 10 4 g/mol, and its polydispersity index is 1.68. All the copolyesters were more thermally stable than the pristine poly(butylene succinate) (PBS). The incorporation of valine units into the copolyesters eventually led to the decrease of the crystallization temperature, melting temperature, while increase of crystallization enthalpy and melting enthalpy. The crystal structure of the copolyesters is similar to pure PBS except for higher degrees of crystallinity; also there was a trend to higher degrees of crystallinity with increasing content of valine. From the enzymatic degradation experiment, it is clear that the PBSVAL 10 copolyester shows less weight loss as compared to pure PBS which is due to PBSVAL 10 with higher degree of crystallinity. The morphology of the copolyester films after degradation was also studied by the scanning electron microscopy. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2021
·
IF 3.764
Wei Li,Jing Yang,Shichao Du,Estevao Macaringue,Yan Wang,Songgu Wu,Junbo Gong
l-Valine crystallizes in a flake-like shape generally; however, compared with the flake-like products, spherulitic l-valine has better filterability, flowability, and bulk density and has potential for wider industrial applications in the future. In this study, l-valine spherulites have been successfully prepared by an evaporative crystallization method in the presence of no more than 0.5% hydroxypropyl methyl cellulose (HPMC). The spheroidization of l-valine proceeds via a layer-by-layer transformation from an initial flake-like shape to a petal-like form, and then it continues to grow into the final sphere-like shape. Molecular dynamics simulations show that HPMC interacts with hydrophilic (001) faces preferentially and promotes the continuous layer growth process. Only the substituent groups of hydroxypropyl and methyl exist simultaneously within a certain spatial distance and, in a viscosity of 40–50 mPa·s, can promote the formation of l-valine spherulites. The particle size increased with the increase in the HPMC dosage and decrease of temperature or evaporation rate. This effect of HPMC promoting the spherical formation provides a method to enrich the design of spherulites and new insights into the fabrication mechanism of spherulitic growth.
研究领域:
化学
·
材料科学
·
晶体学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2015
·
IF 2.752
Jun Huang,Ping Su,Lian Zhou,Yi Yang
Chiral selector-functionalized magnetic microspheres have significantly potential in the recognition and separation of chiral compounds. In this work, novel chiral selector-functionalized magnetic microspheres ( l -Val@G3.0-PMMPs) were achieved by grafting l -valine ( l -Val) on polyamidoamine (PAMAM) dendrimer-modified magnetic microspheres, which were confirmed by various characterization methods. The synthesized l -Val@G3.0-PMMPs had clearly three-layer structure, with a mean diameter of 590 nm and exhibited good dispersion and strong magnetic response. The immobilization amounts of l -Val determined by high performance liquid chromatography with mass spectrometry (HPLC–MS) increased with increasing PAMAM generation, and the results indicated that the PAMAM dendrimer bonded onto the surface of magnetic microspheres obviously improved the immobilization amounts of l -Val. The synthesized l -Val@G3.0-PMMPs as chiral magnetic selectors were used to conduct the enantioselective adsorption of dansyl amino acids. The chiral discrimination ability of the l -Val@G3.0-PMMPs was investigated through determining the enantiomeric excess of the l -Val@G3.0-PMMPs with capillary electrophoresis. Under the optimal amount of l -Val@G3.0-PMMPs and interaction times, the enantiomeric excess of dansyl amino acids adsorbed onto the surface of the l -Val@G3.0-PMMPs was calculated to be 20.1%. The results of enantiomeric excess indicated that the l -Val@G3.0-PMMPs selectively interacted with dansyl amino acid and exhibited excellent chiral discrimination ability. In the future research, the novel l -Val@G3.0-PMMPs are possible to be an efficient and suitable chiral selector for the enantioseparation of chiral compounds.
研究领域:
化学
·
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Pharmaceutics
·
2022
·Vol. 14
·期 6
·1277
·
IF 6.525
Huimin Wu,Yuchen Xu,Mengru Cai,Longtai You,Jing Liu,Xiaoxv Dong,Xingbin Yin,Jian Ni,Changhai Qu
The incidence of ocular surface disease (OSD) is increasing, with a trend towards younger ages. However, it is difficult for drugs to reach the deep layers of the cornea due to ocular surface barriers, and bioavailability is less than 5%. In this study, DSPE-PEG2000 was modified with L-valine (L-Val), and an HS15/DSPE-PEG2000-L-Val nanomicelle delivery system containing baicalin (BC) ([email protected]/DSPE-PEG2000-L-Val) was constructed using thin-film hydration, with a high encapsulation rate, small particle size and no irritation to the ocular surface. Retention experiments on the ocular surface of rabbits and an in vivo corneal permeation test showed that, compared with the control, nanomicelles not only prolonged retention time but also enhanced the ability to deliver drugs to the deep layers of the cornea. The results of a protein inhibition and protein expression assay showed that nanomicelles could increase uptake in human corneal epithelial cells (HCEC) through energy-dependent endocytosis mediated by clathrin, caveolin and the carrier pathway mediated by PepT1 by inhibiting the overexpression of claudin-1 and ZO-1 and suppressing the expression of PepT1-induced by drug stimulation. These results indicate that[email protected]/DSPE-PEG2000-L-Val is suitable for drug delivery to the deep layers of the ocular surface, providing a potential approach for the development of ocular drug delivery systems.Keywords:L-valine;nanomicelles;baicalin;PepT1;endocytosis proteins;tight junction proteins;ocular drug delivery system
研究领域:
药学
·
眼科学
·
纳米技术
·
药物递送系统
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2015
·
IF 2.037
Xiaofen Ren,Chunying Zhu,Youguang Ma
Densities and viscosities of glycine, l-alanine, l-valine, l-threonine, and l-arginine in aqueous solutions of (0.0, 0.2, 0.4, 0.6, 0.8, and 1.0) mol·kg–1 mannitol have been measured in the temperature range of (293.15 to 323.15) K under atmospheric pressure; then the measured densities and viscosities of experimental systems were correlated. These data were further used to calculate the apparent molar volumes (Vφ), the limiting partial molar volumes (Vφ0), the limiting partial molar volumes of transfer (ΔtrVφ0), the viscosity B-coefficients, and the free energies of activation per mole of solvent (Δμ10≠) and solute (Δμ20≠). The results were interpreted through solute–solute interaction and solute–solvent interaction on the basis of the cosphere overlap model and transition state theory.
研究领域:
生物化学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
CHROMATOGRAPHIA
·
2023
·Vol. 86
·期 7
·541-551
·
IF 1.7
Guo Xinyuan,Shang Panpan,Wei Benben,Du Wenrong,Lan Yong,Bai Ligai,Qiao Xiaoqiang,Ma Zhengyue
This study presents the development of three new chiral stationary phases. Three new peptide chiral stationary phases with a main chain of l- proline, l- phenylalanine, l- valine and l- leucine and different terminals of l- citrulline, l- lysine and l- tryptophan immobilized on 3-aminopropyltrimethoxysilane modified silica gel were prepared; furthermore, successful analyses and characterizations were conducted using Fourier transform infrared spectra, elemental analysis, and thermogravimetric analysis. After this, the enantioselective performance of the three peptide stationary phases columns was evaluated. The evaluation used nine racemic compounds under normal-phase high-performance liquid chromatography mode. Optimized enantiomeric separation conditions were established. Under these conditions, the resolutions of flurbiprofen, naproxen, benzoin, 1 ,1ʹ-bi-2-naphthol and ketoprofen on the CSP-1 column were 1.61, 2.0, 0.62, 0.52 and 1.20, respectively. In addition, the reproducibility of the CSP-1 column was also investigated. The results of the investigation illustrated that the stationary phases have good reproducibility (RSD = 0.12%, n = 5).
研究领域:
分析化学
·
色谱学
·
材料科学
·
分离科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 53
·期 10
·7793-7808
·
IF 2.993
Dong Chundong,Zhang Manxin,Xiang Tengfei,Yang Ling,Chan Wenming,Li Cheng
This work creatively utilized the pH-dependent electrostatic interactions between L-valine (L-Val) and halloysite nanotubes (HNTs) to fabricate pH-responsive anticorrosion materials and compared with 2-mercaptobenzothiazole (MBT)-loaded HNTs, which were assembled via layer-by-layer (LbL) self-assembly. These two methods can achieve controlled release of inhibitors and self-healing performance. However, the loading capacity of L-Val-loaded HNTs is higher than that of MBT’s. There are 12 and 7 wt%, respectively. The pH-responsive release property was systematically evaluated by ultraviolet–visible (UV/Vis) spectrophotometry measurement. It demonstrates that 98% of adsorbed L-Val molecules released from HNTs within 300 min at pH 10 while the loaded MBT needs 120 h to achieve the equal ratio. Moreover, the difference of the release rate has a significant impact on the artificial crossed scratch experiment and shows a great performance gap in photographs. By comparing electrochemical impedance spectroscopy (EIS) data of three epoxy coatings, it can be seen that the epoxy coating, which was mixed with L-Val-loaded HNTs, shows a better anticorrosion ability than the epoxy coating contains MBT-loaded HNTs after immersion in 3.5 wt% sodium chloride solution for 96 h. Crucially, the pH-responsive anticorrosion material we fabricated can offer a rapid self-healing performance when the coating damaged by mechanical scratch via visual test and atomic absorption spectroscopy.
研究领域:
材料科学
·
化学工程
·
腐蚀科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Materials Science & Engineering C-Materials for Biological Applications
·
2021
·
IF 7.328
Zuofa Yan,Xiangjun Meng,Yun Su,Yiqing Chen,Lidong Zhang,Jialu Xiao
Electrospun membranes and hydrogels are widely used to prevent tendon adhesion. Hydrophobic anti-inflammatory drugs could be fully loaded on the electrospinning membrane through the electrospinning process, which can better prevent tendon adhesion. Basic fibroblast growth factor (bFGF) could promote tendon healing. However, the bioactivity of free bFGF is easily inactivated, therefore, a suitable carrier is needed. As a carrier, hydrogel has little effect on the bioactivity of the protein drugs. In this work, a poly(lactic- co -glycolic) acid (PLGA) electrospun membrane loaded with ibuprofen (IBU) was prepared and named EMI. Additionally, Methoxy poly(ethylene glycol)- block -poly(L-valine) (PEG-PLV) was synthesized. bFGF was added to the PEG-PLV solution, a hydrogel containing bFGF (PLVB) was obtained after gelling. PLVB was applied to the surface of EMI, a double-layer composite membrane named EMI-PLVB was obtained. This membrane was used to prevent Achilles tendon adhesion and promote healing. IBU and bFGF in EMI-PLVB were continuously released in vitro. The inflammatory factors at the tendon healing site were significantly reduced, and the production of type I collagen (Col- I) and type III Collagen (Col-III) at the tendon healing site was also increased in vivo. In conclusion, this double-layer composite membrane drug release system can effectively prevent tendon adhesion and promote tendon healing.
研究领域:
生物医学工程
·
组织工程
·
药学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHIRALITY
·
2022
·Vol. 34
·期 3
·462-472
·
IF 2.183
Zhen Wang,Wan-Qi Xiong,Zhi-Feng Huang,Gai-Zhao Qin,Min Zi,Li-Ming Yuan
Chiral covalent organic framework materials have many excellent properties, which have received much attention in the field of separation. Synthesized the covalent organic framework COF-TpBD (NH 2 ) 2 modified, respectively, by L-valine trifluoroacetyl derivative, L-hydroxyproline, and (1S)-(+)-10-camphorsulfonyl chloride, three capillary columns of chiral covalent organic framework materials were obtained for gas chromatography. Those columns are able to separate some chiral compounds, positional isomers, n-alkanes, n-alcohols, aromatic hydrocarbon mixture, and Grob's reagents. They are complementary to other chiral capillary columns and are possible for potential applications.
研究领域:
分析化学
·
材料科学
·
色谱学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）