ANALYTICA CHIMICA ACTA
·
2021
·
IF 6.558
Xiaojuan Zhou,Qiang Liu,Xiaoyu Shi,Chunli Xu,Baoxin Li
In this work, three kinds of gold nanorods (AuNRs) with different aspect ratios were synthesized through conventional seed-mediated growth method, and the chirality of these AuNRs were characterized by circular dichroism (CD) spectroscopy. The results showed that the AuNRs with bigger aspect ratio had larger chirality. The AuNRs with different aspect ratios were applied to distinguish the enantiomers of 19 kinds of α -amino acids. It was found that AuNRs with bigger aspect ratio exhibited the stronger chiral recognition ability. As a proof-of-principle, the AuNRs with the aspect ratio of 4.8 were used to quantitatively recognize enantiomers of valine . Furthermore, the microcalorimetry was applied to study the interaction of AuNRs with amino acid enantiomers. This work provides one method to improve the chiral recognition ability of AuNRs by optimizing the aspect ratio of AuNRs, and helps people better understand the intrinsic chirality of nanostructures .
研究领域:
纳米生物学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2024
·
IF 4.7
Rui Zhu,Yaxin Wang,Minshu Cui
A strategy for the photocatalytic conversion of α-amino acids into corresponding amides was developed. A series of carbon nitride samples were prepared as the catalyst. Various characterizations of the catalyst indicated that effective photocatalytic activity and low recombination efficiency of photo-generated carriers were significant for the high activity of the catalyst. Reaction conditions for the photocatalytic decarboxylation of α-amino acids were optimized, alongside an investigation into the potential mechanism through controlled experiments and DFT computations. Mechanism studies unveiled that photo-generated electrons activated O 2 to reactive oxygen species, while photo-generated holes induced the decarboxylation reactions by activating the carboxylic acid groups, generating carbon radicals that ultimately lead to the formation of corresponding amides under the influence of reactive oxygen species. Moreover, the photocatalytic decarboxylation of different alpha amino acids was also discussed, providing new strategies for the formation of amides and lactams.
研究领域:
有机化学
·
催化化学
✓ 已验证
DOI
高影响因子
Journal of Chemical Information and Modeling
·
2025
·
IF 5.3
Binbin Chen,Jiahui Huang,Yingchun Liu,Lirong Yang,Qi Wang,Haoran Yu
The catalytic mechanism of a pyridoxal 5′-phosphate (PLP)-dependent UstD was herein studied in atomic detail, employing the computational hybrid QM/MM methodology. UstD is a PLP-dependent enzyme that catalyzes the decarboxylative aldol reactions between l-aspartate and aldehyde or ketone derivatives to form γ-hydroxy-α-amino acids. In the reaction catalyzed by UstD, the loss of CO2 renders the C–C bond-forming reaction effectively irreversible, which makes UstD a special case among the enzymes catalyzing the C–C bond-forming reactions. This enzyme is currently seen as the optimal approach for the regioselective synthesis of γ-hydroxy-α-amino acids, which are very difficult to obtain by standard chemical methods. The results obtained herein showed that the catalytic mechanism of UstD might follow two paths to occur in three phases: (1) decarboxylation of substrate l-aspartate, (2) C–C bond formation by addition of aldehyde, and (3) the regeneration of catalytic sites. Although Path A and Path B showed a negligible difference in the energy barrier of the rate-determining step, Path A involves three additional steps in the overall pathway compared with Path B, which makes the reaction proceed more readily through Path B. According to the QM/MM energy profile of Path B, the rate-limiting step of the catalytic process is the decarboxylation of the side chain of l-aspartate, which has a calculated energy barrier of 19.19 kcal/mol. Two crucial residues, H263 and Y257, were identified to interact with the substrate aspartic acid. The knowledge about the transition states, intermediates, key residues, and protein conformational changes along the reaction path will be valuable for engineering UstD to improve the synthesis of γ-hydroxy-α-amino acids that serve as building blocks of various high-value chemicals such as antidiabetics and nutritional supplements.
研究领域:
生物化学
·
计算生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Biomaterials Science
·
2015
·Vol. 3
·期 7
·1134-1146
·
IF 3.831
Jiaolong Lv,Huanli Sun,Yan Zou,Fenghua Meng,Aylvin A. Dias,Marc Hendriks,Jan Feijen,Zhiyuan Zhong
Novel reductively degradable α-amino acid-based poly(ester amide)-graft-galactose (SSPEA-Gal) copolymers were designed and developed to form smart nano-vehicles for active hepatoma-targeting doxorubicin (DOX) delivery. SSPEA-Gal copolymers were readily synthesized via solution polycondensation reaction of di-p-toluenesulfonic acid salts of bis-L-phenylalanine 2,2-thiodiethanol diester and bis-vinyl sulfone functionalized cysteine hexanediol diester with dinitrophenyl ester of adipic acid, followed by conjugating with thiol-functionalized galactose (Gal-SH) via the Michael addition reaction. SSPEA-Gal formed unimodal nanoparticles (PDI = 0.10 − 0.12) in water, in which average particle sizes decreased from 138 to 91 nm with increasing Gal contents from 31.6 wt% to 42.5 wt%. Notably, in vitro drug release studies showed that over 80% DOX was released from SSPEA-Gal nanoparticles within 12 h under an intracellular mimicking reductive conditions, while low DOX release (<20%) was observed for reduction-insensitive PEA-Gal nanoparticles under otherwise the same conditions and SSPEA-Gal nanoparticles under non-reductive conditions. Notably, SSPEA-Gal nanoparticles exhibited high specificity to asialoglycoprotein receptor (ASGP-R)-overexpressing HepG2 cells. MTT assays using HepG2 cells showed that DOX-loaded SSPEA-Gal had a low half maximal inhibitory concentration (IC50) of 1.37 μg mL−1, approaching that of free DOX. Flow cytometry and confocal laser scanning microscopy studies confirmed the efficient uptake of DOX-loaded SSPEA-Gal nanoparticles by HepG2 cells as well as fast intracellular DOX release. Importantly, SSPEA-Gal and PEA-Gal nanoparticles were non-cytotoxic to HepG2 and MCF-7 cells up to a tested concentration of 1.0 mg mL−1. These tumor-targeting and reduction-responsive degradable nanoparticles have appeared as an interesting multi-functional platform for advanced drug delivery.
研究领域:
生物材料学
·
药物递送系统
·
肿瘤治疗
✓ 已验证
DOI
PubMed
高影响因子
ANALYST
·
2016
·Vol. 141
·期 4
·1257-1265
·
IF 4.033
Guoxin Song,Fulin Zhou,Chunli Xu,Baoxin Li
The ability to recognize and quantify the chirality of alpha-amino acids constitutes the basis of many critical areas for specific targeting in drug development and metabolite probing. It is still challenging to conveniently distinguish the enantiomer of amino acids largely due to the lack of a universal and simple strategy. In this work, we report a strategy for the visual recognition of α-amino acids. It is based on the chirality of L-tartaric acid-capped gold nanoparticles (L-TA-capped AuNPs, ca. 13 nm in diameter). All of 19 right-handed α-amino acids can induce a red-to-blue color change of L-TA-capped AuNP solution, whereas all of the left-handed amino acids (except cysteine) cannot. The chiral recognition can be achieved by the naked eye and a simple spectrophotometer. This method does not require complicated chiral modification, and excels through its low-cost, good availability of materials and its simplicity. Another notable feature of this method is its high generality, and this method can discriminate almost all native α-amino acid enantiomers. This versatile method could be potentially used for high-throughput chiral recognition of amino acids.
研究领域:
分析化学
·
生物化学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMISTRY
·
2021
·Vol. 39
·期 10
·2852-2856
·
IF 6
Peng Zhou,Zixian Li,Yanzhi Lu,Jie Kong,Jun Ling
Main observation and conclusion Block copolymers not only combine properties of different segments but also generate new application prospects. Poly(α-amino acid)- b -poly(tetrahydrofuran)- b -poly(α-amino acid) (PAA-PTHF-PAA) is one of the copolymers. In this contribution, di-hydroxyl-ended HO-PTHF-OH is transferred into di-oxyamino-ended H 2 NO-PTHF-ONH 2 quantitatively, which is used as a macroinitiator to polymerize sarcosine N -thiocarboxyanhydride (Sar-NTA) and N -phenyoxycarbonyl N -ε-carbobenzyloxy- D -lysine (ZDL-NPC). Well-defined triblock PAA-NHO-PTHF-ONH-PAA is produced with high molecular weight (up to 25.3 kg/mol) and narrow dispersity. The amphiphilic PSar-NHO-PTHF-ONH-PSar (STS) self-assembles into micelles with uniform diameters of 30—40 nm according to DLS. Owing to oxygen amide groups inside the backbone of these copolymers, the polyether-poly(amino acid)s block copolymers are cleavable under an acidic environment and therefore have potential applications in smart biomedicine and engineering.
研究领域:
高分子化学
·
生物材料
·
生物医药
✓ 已验证
DOI
高影响因子
Analytical Methods
·
2016
·Vol. 8
·期 29
·5794-5800
·
IF 1.915
Cunwei Liu,Jinyu Lian,Qiang Liu,Chunli Xu,Baoxin Li
Efficient enantiomer discrimination by a convenient method remains a challenge in biochemical and pharmaceutical fields. Herein we have modified silver nanoparticles (AgNPs) with β-cyclodextrin (β-CD) to obtain a probe for the chiral recognition of aromatic α-amino acids. This assay relies on the distance-dependent optical properties of AgNPs and the difference in inclusion binding strength between the aromatic amino acid enantiomers and the β-CD host. The response of β-CD functionalized-AgNPs to certain chiral aromatic amino acid enantiomers namely D- and L-phenylalanine (Phe), D- and L-tryptophan (Trp), and D- and L-tyrosine (Tyr) in phosphate buffer solutions was studied in detail. In the presence of D-Phe (or L-Trp or L-Tyr), an appreciable yellow-to-red color change of the AgNP solution can be observed, whereas no color change is found in the presence of L-Phe (or D-Trp or D-Tyr). This method can be used to quantitatively determine the percentage of D-Phe in a mixture of D- and L-Phe. The chiral assay described in this work is easily readout with the naked eye or using a cheap UV-vis spectrometer. This method excels by its simplicity, low cost, and good availability of materials.
研究领域:
生物化学
·
制药科学
·
材料科学
✓ 已验证
DOI
高影响因子
Nature Communications
·
2025
·Vol. 16
·期 1
·1-14
·
IF 15.7
Zhang Pengbo,Liu Yuzhu,Wei Jie,Wu Zuoao,Song Xinmei,Ding Guochun,Wang Huaizhu,Liang Junchuan,Tie Zuoxiu,Jin Zhong
Aqueous organic redox flow batteries offer promising prospects for large-scale, high-safety, and cost-effective energy storage systems with no reliance on scarce mineral resources. However, challenges such as limited water solubility and poor stability hinder the practical application of organic redox molecules in aqueous organic redox flow batteries. Herein, we report the design and synthesis of an artificial redox-active α-amino acid molecule by functionalizing 1,5-dihydroxyanthraquinone with natural cysteine side group, which exhibits enhanced aqueous solubility and redox reversibility in alkaline aqueous organic redox flow batteries. Owing to its unique zwitterionic structure and abundant hydrogen bonds, the negolyte based on artificial α-amino acid molecule exhibits a very low capacity decay rate of 0.00025% per cycle (equivalent to 0.011% per day) under 1 M electron transfer. Theoretical simulations and spectroscopic analyses underscore the importance of the symmetric distribution and abundant hydrogen-bonding interactions of amphipathic amino acid side chains in enhancing the stability of the anthraquinone redox core and reducing its dimerization, as well as enhancing its water solubility and redox reversibility. This study presents the promising potential of nature-inspired principles in designing electrochemically stable, redox-active organic molecules, contributing to the advancement of large-scale, biocompatible, and sustainable aqueous organic redox flow batteries.
研究领域:
能源化学
·
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2018
·Vol. 41
·期 6
·1479-1488
·
IF 2.415
Qing Xiong,Jing Jin,Liqiong Lv,Zhisi Bu,Shengqiang Tong
This work deals with the enantioseparation of α-amino acids by chiral ligand exchange high-speed countercurrent chromatography using N - n -dodecyl- l -hydroxyproline as a chiral ligand and copper(II) as a transition metal ion. A biphasic solvent system composed of n -hexane/ n -butanol/aqueous phase with different volume ratios was selected for each α-amino acid. The enantioseparation conditions were optimized by enantioselective liquid–liquid extractions, in which the main influence factors, including type of chiral ligand, concentration of chiral ligand and transition metal ion, separation temperature, and pH of the aqueous phase, were investigated for racemic phenylalanine. Altogether, we tried to enantioseparate 15 racemic α-amino acids by the analytical countercurrent chromatography, of which only five of them could be successfully enantioseparated. Different elution sequence for phenylalanine enantiomer was observed compared with traditional liquid chromatography and the proposed interactions between chiral ligand, transition metal ion (Cu 2+ ), and enantiomer are discussed.
研究领域:
分析化学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOMATERIALS
·
2018
·
IF 8.806
Chong Zhang,Jingsong Yuan,Jianhua Lu,Yingqin Hou,Wei Xiong,Hua Lu
s The development of high-performance nonfouling polymer surfaces for implantable medical devices and therapeutic nanomaterials is of great importance. Elaborating the relationship of polymer structural characteristics and the resulted surface properties can offer useful guidance toward ideal biointerfaces . In this work, we investigate the effects of the helical conformation and anchoring orientation of poly(α-amino acid)s (PαAAs) to produce advanced nonfouling surfaces. By using the neutral poly(γ-(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)esteryl glutamates) (P(EG 3 Glu)s) as a model system, the adsorption kinetics are monitored by ex-situ variable angle spectroscopic ellipsometry and in-situ quartz crystal microbalance with dissipation . It is found that the polymers adopting a rigid rod-like α-helical conformation can self-assemble more rapidly to produce denser adlayers, and generate significantly improved nonfouling surfaces compared to those flexible polymer analogues including the widely used antifouling polymer PEG . Moreover, the surface properties can be further enhanced by using the antiparallel orientated helical P(EG 3 Glu)s. Most importantly, the insights gained from the P(EG 3 Glu) model system are successfully applied to the generation of ultra-low-fouling surfaces using zwitterionic PαAAs brushes, underscoring the generality of the approach. Particularly, the surface based on the antiparallel aligned zwitterionic helical PαAAs exhibits ∼98–99% reduction of human serum adsorption relative to the bare gold, and gives almost no adhesion of mouse platelet. Taken together, this work depicts an extremely simple yet highly effective approach to manipulate surface properties for numerous applications in biomaterial interfaces, diagnostics, and biosensors.
研究领域:
生物材料
·
生物医学工程
·
界面科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2010
·Vol. 48
·期 23
·5364-5374
·
IF 3.971
You-Mei Bao,Xiao-Hui Liu,Xiu-Lan Tang,Yue-Sheng Li
A series of novel hyperbranched poly(ester-amide)s (HBPEAs) based on neutral α-amino acids have been synthesized via the “AD + CBB′” couple-monomer approach. The ABB′ intermediates were stoichiometrically formed through thio-Michael addition reaction because of reactivity differences between functional groups. Without any purification, in situ self-polycondensations of the intermediates at elevated temperature in the presence of a catalyst afforded HBPEAs with multihydroxyl end groups. The degrees of branching (DBs) of the HBPEAs were estimated to be 0.40–0.58 and 0.24–0.54 by quantitative 13 C NMR with two different calculation methods, respectively, depending on polymerization conditions and structure of monomers. The influences of catalyst, temperature, and intermediate structure on the polymerization process and molecular weights as well as properties of the resultant polymers were investigated. FTIR, NMR, and DEPT-135 NMR analyses revealed the branched structure of the resultant polymers. The HBPEAs possess moderately high molecular weights with broad distributions, glass transition temperatures in the range of −25.5 to 36.5 °C, and decomposition temperatures at 10% weight loss under nitrogen and air in the regions of 243.4–289.1 °C and 231.4–265.6 °C, respectively. Among them, those derived from D , L -phenylalanine display the lowest degree of branching, whereas the highest glass transition temperature and the best thermal stability. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
研究领域:
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2020
·
IF 3.232
Mei-Xiang Yang,Qing Tang,Mei Yang,Qin Wang,Zhu Tao,Xin Xiao,Ying Huang
The host–guest inclusion complexes that comprise an inverted cucurbit[7]uril ( i Q[7]) and a quinoline derivative, 4-(4-dimethylaminostyryl) quinoline (DSQ) at different pHs were exploited as multiple supramolecular sensors to sense l -α-amino acids. DSQ complexation inside i Q[7] at different pHs leads to increased fluorescence and formation of different-colored i Q[7]-DSQ complexes. The enhanced fluorescence of DSQ after i Q[7] encapsulation may be attributed to limited dimethylamine rotation and the formation of a twisted internal charge transfer (TICT) state. The DSQ@ i Q[7] sensors have different affinities for l -α-amino acids at different pHs. Therefore, we propose a pH-stimulus response supramolecular sensor for the discrimination of structurally similar l -α-amino acids in aqueous solution.
研究领域:
分析化学
·
超分子化学
✓ 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）