CRYSTENGCOMM
·
2024
·Vol. 26
·期 7
·943-950
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IF 2.6
Jinqiu Fu,Mengyang Cai,Yuzhong Shi,Yihang Hou,Rongxi Guo,Chiyi Wang,Jingjing Zhao,Wei Zhuang,Hanjie Ying,Pengpeng Yang,Keke Zhang
L-Alanyl-L-glutamine (Ala–Gln) is a dipeptide which is widely used in medical and nutritional fields. Two new crystalline forms (form III and form IV) and a DMSO solvate form (SDMSO) of Ala–Gln were discovered in this study, which were distinguished from the known forms by Raman spectroscopy and powder X-ray diffraction (PXRD). Single crystal structures of the three new solid forms were obtained. Moreover, the crystal structure data of known forms: form II, dihydrate form (2H) and ethanol solvate form (SEtOH), which have not been reported to the best of our knowledge, were solved. The results showed that there were four kinds of molecular arrangements and frameworks in the Ala–Gln solid forms. The comparison of the molecular arrangements and cell parameters indicated that the forms III, 2H and SEtOH were isomorphic. The hydrogen bonding network of the DMSO solvate was different from those of forms II, III and IV. By comparing the bulk density, lattice energy and thermal analysis results of the three polymorphs of Ala–Gln, the order of bulk density and lattice energy was consistent with the decomposition enthalpy. Besides that, it was found that the crystal shape of the solvates can be retained after solvent removal.
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FOOD AND CHEMICAL TOXICOLOGY
·
2019
·
IF 3.775
Congyong Sun,Wenjing Li,Yingkun Liu,Wenwen Deng,Michael Adu-Frimpong,Huiyun Zhang,Qilong Wang,Jiangnan Yu,Ximing Xu
1-O-(4-hydroxymethylphenyl)-α-L-rhamnopyranoside (MPG) is a phenolic glycoside that exists in Moringa oleifera seeds with various health benefits, whereas its hepatoprotective effect is lacking clarification. Herein, MPG was isolated from Moringa oleifera seeds, and its hepatoprotection against CCl 4 -induced hepatotoxicity in L02 cells and ICR mice was investigated. Toxicity studies showed that MPG did not induce significant changes in organ coefficients and histological analysis, as well as exhibited no cytotoxicity. In vitro studies indicated that MPG substantially increased cell viability and intracellular SOD activities, and significantly inhibited LDH leakage in CCl 4 -treated cells. In vivo studies demonstrated that MPG significantly alleviated CCl 4 -induced hepatotoxicity in mice, as indicated by diagnostic indicators of hepatic injury, as well as the histopathological analysis. Moreover, MPG reduced the lipid peroxidation levels and regulated the inflammatory cytokines. Notably, MPG substantially suppressed the significant elevation of ROS production in hepatocytes of mice intoxicated with CCl 4 . Moreover, TUNEL assay demonstrated that MPG obviously inhibited hepatic apoptosis induced by CCl 4 . Altogether, these results suggested that MPG has excellent liver-protecting effects against hepatocytotoxicity induced by CCl 4 in mice and L02 cells, which can be further developed as a valuable functional food additive or drug for the treatment of hepatic injury.
研究领域:
药理学
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毒理学
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肝脏病学
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营养保健品
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DOI
PubMed
高影响因子
Advanced Healthcare Materials
·
2022
·Vol. 11
·期 15
·2200386
·
IF 11.092
Jile Xie,Jiaying Li,Jinjin Ma,Meimei Li,Xingran Wang,Xinya Fu,Yanxia Ma,Huilin Yang,Bin Li,Saijilafu
Because of the limited regenerative ability of the central nervous system (CNS), effective treatments for spinal cord injury (SCI) are still lacking. After SCI, neuron loss and axon regeneration failure often result in irreversible functional impairment. The calcium overload induced by the N-methyl-D-aspartate receptor (NMDAR) overactivation is critical for cell death in SCI. It has been reported that the magnesium ion (Mg 2+ ) can competitively block the NMDAR and reduce the calcium influx, and that sonic hedgehog (Shh) and retinoic acid (RA) are the critical regulators of neuronal differentiation of endogenous neural stem cells (NSCs). Here, magnesium oxide (MgO)/poly ( l -lactide-co- ε -caprolactone) (PLCL) scaffold loaded with purmorphamine (PUR, a Shh signaling agonist) and RA is developed and its feasibility in SCI repair is tested. The results showed that the Mg 2+ released from MgO attenuated cell apoptosis by blocking the calcium influx, and the PUR/RA promoted the recruitment and neuronal differentiation of endogenous NSCs, thereby reducing the glial scar formation at the SCI lesion site. Furthermore, implantation of PUR/RA-loaded MgO/PLCL scaffold facilitates the partial recovery of a locomotor function of SCI mouse in vivo. Together, findings from this study imply that PUR/RA-loaded MgO/PLCL scaffold may be a promising biomaterial for the clinical treatment of SCI.
研究领域:
神经科学
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生物材料
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再生医学
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干细胞生物学
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PubMed
高影响因子
AQUACULTURE
·
2024
·
IF 3.9
Kunyin Jiang,Hong Yu,Lingfeng Kong,Shikai Liu,Shaojun Du,Qi Li
The visually appealing shell colours and intricate patterns of shellfish not only attract consumers but also enhance their economic value. Understanding the inheritance pattern of shell colour and the molecular mechanism of pigmentation is highly important for enhancing breeding efficiency. This study involved the identification of a tyrosine hydroxylase gene ( CgTH ) and the investigation of its function in the metabolism of tyrosine and pigmentation in Pacific oysters. CgTH contains a conserved Biopterin_H domain that consists of a binding site for iron atoms and a binding site for tetrahydrobiopterin (BH4). Quantitative PCR (qPCR) and immunofluorescence analysis revealed that the expression of CgTH was higher in the mantle of black shell oysters in comparison to the white strain. The in vitro and in vivo experiments confirmed that Cg TH is involved in tyrosine metabolism through the catalysis of the conversion of L-tyrosine to L-DOPA. In order to examine its functions in melanin synthesis in oysters, 3-Iodo-L-tyrosine (3-IT) treatment, RNA interference (RNAi), and L-DOPA treatment assays were conducted. The results of our study showed that 3-IT effectively inhibited Cg TH activity, leading to a suppression of tyrosine metabolism. Knockdown of Cg TH hindered the cAMP-CREM-MITF axis and decreased pigmentation. On the other hand, L-DOPA stimulated melanin production through cAMP signaling and counteracted the inhibitory effects of 3-IT on the metabolism of tyrosine. These data indicated that there may be a feedback loop involving Cg TH and the cAMP-CREM-MITF axis that regulates tyrosine metabolism and melanogenesis in Pacific oysters. This study enhances our understanding of the molecular mechanism that governs oyster pigmentation and offers a possible molecular indicator for the targeted breeding of particular strains of Pacific oysters ( Crassostrea gigas ).
研究领域:
海洋生物学
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分子生物学
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遗传学
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水产养殖
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高影响因子
CHEMBIOCHEM
·
2023
·
IF 3.2
Xin Li,Changzheng Gao,Wanqing Wei,Wei Song,Weiwei Meng,Jia Liu,Xiulai Chen,Cong Gao,Liang Guo,Liming Liu,Jing Wu
Graphical We developed a pathway for the synthesis of L-ABA in a tri-enzymatic cascade in Escherichia coli BL21 (DE3) using L-Thr, and the expression of three enzymes was optimized by vector design. We solved the crystal structure of the key enzyme LDH and proposed protein engineering strategies based on the structure to improve the catalytic activity of the enzyme. L-2-aminobutyrate (L-ABA) is an important chiral drug intermediate with a key role in modern medicinal chemistry. Here, we describe the development of an efficient method for the asymmetric synthesis of L-ABA in a tri-enzymatic cascade in Escherichia coli BL21 (DE3) using a cost-effective L-Thr. Low activity of leucine dehydrogenase from Bacillus thuringiensis ( Bt LDH) and unbalanced expression of enzymes in the cascade were major challenges. Mechanism-based protein engineering generated the optimal triple variant Bt LDH M3 (A262S/V296C/P150M) with 20.7-fold increased specific activity and 9.6-fold increased k cat / K m compared with the wild type. Optimizing plasmids with different copy numbers regulated enzymatic expression, thereby increasing the activity ratio (0.3 : 1:0.6) of these enzymes in vivo close to the optimal ratio (0.4 : 1 : 1) in vitro . Importing the optimal triple mutant Bt LDH M3 into our constructed pathway in vivo and optimization of transformation conditions achieved one-pot conversion of L-Thr to 130.2 g/L L-ABA, with 95 % conversion, 99 % e.e . and 10.9 g L −1 h −1 productivity (the highest to date) in 12 h on a 500 mL scale. These results describe a potential biosynthesis approach for the industrial production of L-ABA.
研究领域:
生物化学
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生物技术
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蛋白质工程
·
酶学
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PubMed
高影响因子
EUROPEAN POLYMER JOURNAL
·
2017
·
IF 3.531
Le Li,Zhi-Qiang Cao,Rui-Ying Bao,Bang-Hu Xie,Ming-Bo Yang,Wei Yang
Different from traditional small molecular plasticizers, poly( l -lactic acid) (PLLA)-polyethylene glycol (PEG)-PLLA triblock copolymers were synthesized by ring-opening polymerization of L-lactide on the end hydroxyls of PEG and blended with PLLA, to enhance the crystallization of PLLA. Non-isothermal and isothermal crystallization studies show that the triblock copolymer enhances the crystallization of PLLA due to the nucleation effect from PLLA segments and the plasticization effect from PEG segments, which strongly depends on the structure of copolymers. With shorter PLLA segment and longer PEG segment of the triblock copolymer, the glass transition temperature and cold crystallization temperature of the blends decrease, and the degree of crystallinity and spherulite growth rate increase owing to the higher content of PEG. However, triblock copolymers with relatively longer PLLA segment and shorter PEG segment show unique nucleation effects for PLLA, leading to the elevation of crystallization temperature of PLLA. The results confirm that the crystallization acceleration of PLLA can be ascribed to the nucleation and plasticization effect, and the plasticization effect is more significant. What’s more, the introduction of triblock copolymers improves the compatibility and durability due to the good interfacial interaction with PLLA matrix even at a high loading.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2026
·
IF 2.4
Vladimir B. Motalov,Mikhail A. Korobov,Andrey S. Kaplin,Anatoliy M. Dunaev,Elena Yu. Tyunina,Vitaly V. Kolobov,Lev S. Kudin
Special mild conditions (temperature range and duration) were selected for Knudsen effusion mass spectrometric thermodynamic studies of low-volatility amino acids l-histidine and l-aspartic acid, which made it possible to avoid any significant degradation of the starting materials, as evidenced by IR spectroscopy and visual observation. The saturated vapor pressure data in the studied temperature range are described by a linear equation ln(p/Pa) = −(21983 ± 485)/T + (42.411 ± 1.029) for l-histidine (448–480 K) and ln(p/Pa) = −(22350 ± 600)/T + (43.757 ± 1.351) for l-aspartic acid (420–450 K); the overall uncertainty that follows the ± sign includes statistical (expanded standard uncertainty with k = 2) and systematic components. The pressures of these two compounds are of the same order, but l-histidine is most likely slightly less volatile. The enthalpy of sublimation was determined by the methods of the second and third laws of thermodynamics; the recommended values are 183.5 ± 4.2 kJ·mol–1 for l-histidine and 183.2 ± 3.6 kJ·mol–1 for l-aspartic acid. The enthalpy of formation of the gaseous amino acids was found to be −283.2 ± 5.0 kJ·mol–1 for l-histidine and −791.1 ± 4.6 kJ·mol–1 for l-aspartic acid.
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POLYMER
·
2026
·
IF 5.1
Xiaodong Fang,Xiaodie Zhu,Sheng Wang,Xiaohong Li,Yingfeng Tu
l -Lactide ( L -LA) is an important intermediate for the industrial production of poly( l -lactic acid) (PLLA). However, it remains a challenge to afford L -LA in high yield, high efficiency, and high optical purity. Here, we report an efficient catalytic cyclodepolymerization (CDP) of PLLA under relatively mild temperatures (≤180 °C) and high vacuum to afford L -LA with high optical purity. Sixteen commercial metal and organic base catalysts are employed for CDP. For most metal catalysts, efficient PLLA CDP for L -LA with a high yield exceeding 90% can be achieved within 4 h. The crude L -LA is composed of >95% L -LA, which displays a high optical purity with a high ee % value over 99% after recrystallization. Various influencing factors on CDP are carefully investigated. Our results reveal that increasing the depolymerization temperature, time and catalyst loading can significantly boost the yield of crude L -LA, but excessive temperature and high catalyst loading tend to deteriorate the purity of L -LA. Notably, the recycled catalyst can be reused repeatedly for CDP with no evident loss of catalytic efficiency and stereoselectivity. The CDP of PLLA for L -LA follows an intramolecular backbiting mechanism, which accompanies with the occurrence of intermolecular transesterification. Moreover, the obtained high-purity L -LA can be further used to fabricate PLLA with high molecular weight and good crystallinity.
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INDUSTRIAL CROPS AND PRODUCTS
·
2018
·
IF 3.849
Shujie Ma,Leilei Fu,Siqi He,Xiaopeng Lu,Yuanyong Wu,Zhiqing Ma,Xing Zhang
The evaluation of herbicidal activity and the isolation of plant allelopathic substances can lead to the discovery of new herbicide. This study has confirmed that the ethanol extract of S. mukorossi leaves was inhibitory to growth of Avena fatua L. and Amaranthus retroflexus L. both in petri dish experiment and pot culture assay, with the fresh weight inhibition varied between 47.60% and 62.05% at a concentration of 40 g/L of the leaf extract, being comparable to that of a commercialized natural product herbicide pelargonic acid at a concentration of 4 g/L. Five herbicidal compounds, oleanolic acid (1) , lupeol (2) , d-pinitol (3) , hexadecanoic acid (4) and octadecanoic acid (5) were isolated from the most active fraction, petroleum ether extract. D-pinitol (3) showed the highest growth inhibitory activity against both the shoot and root of A. fatua , with the half maximal inhibitory concentration (IC 50 ) values of 53.61 and 56.43 μg/mL, respectively. Furthermore, oleanolic acid (1) and d-pinitol (3) also inhibited the growth of A. retroflexus with the IC 50 value of 56.05 and 61.89 μg/mL against shoot growth, and 58.07 and 66.70 μg/mL against root growth, respectively. Thus, oleanolic acid (1) and d-pinitol (3) are the main phytotoxin constituents of S. mukorossi , and these compounds have the potential for further development as a botanical herbicide.
研究领域:
植物生理学
·
化感作用
·
天然产物化学
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杂草科学
·
农药学
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高影响因子
ELECTROCHIMICA ACTA
·
2021
·
IF 6.901
Xiaofeng Wei,Ying Chen,Shan He,Huiting Lian,Xuegong Cao,Bin Liu
Metal-organic framework (MOF)-based electrochemical interface presents a broad platform for the chiral recognition of amino acids , but the inferior conductivity of most MOFs limits the sensitivity in practical applications of electrochemical sensing. Therefore, the L-histidine-regulated zeolitic imidazolate framework (L-His-ZIF) was proposed as a novel electrochemical interface for simple, efficient, and enantioselective determination of L-glutamate (L-Glu) based on the electrochemical impedance spectroscopy (EIS). Based on the resistance change, the L-His-ZIF interface can be directly used for chiral recognition without the assistance of high-conductive substances, where multiple immobilizations are generally required in MOF-involved voltammetry . The stacked L-His-ZIF nano-polyhedrons provided numerous cavities and high specific surface area, thereby forming adequate chiral recognition sites. Based on the L-His-ZIF interface, the enantioselective detection of l -Glu-was successfully achieved with a good linear relationship with the impedance difference in the range from 0.1 nM to 50 nM with the detection limit of 0.06 nM. This prepared ZIF-functionalized electrode provided the desired enantioselectivity and reproducibility with robust chiral recognition in the real application. More importantly, MOF-modified EIS can be applied for more chiral recognition of enantiomers by various MOF interfaces, which has great potential for applications in pharmaceutical monitoring and biochemical analysis.
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MACROMOLECULES
·
2017
·
IF 5.835
Dongdong Zhou,Shaoyong Huang,Jingru Sun,Xinchao Bian,Gao Li,Xuesi Chen
The crystallization behaviors and microstructures of poly(l-2-hydroxyl-3-methylbutanoic acid)/poly(l-lactide) blends [P(L-2H3MB)/PLLA] were investigated by OM, DSC, SAXS, in situ temperature-dependent WAXD, and in situ synchrotron WAXS. The blends exhibited a homogeneous state at 250 °C. In the cooling process, P(L-2H3MB), with higher melting temperature, crystallized first at 166.7 °C and drove the formation of the phase separation and microstructure. And the amorphous P(L-2H3MB) and PLLA were excluded into the interlamellar and interfibrillar regions of the former P(L-2H3MB) crystallites. For P(L-2H3MB)/PLLA (5/5), the amorphous P(L-2H3MB) in the interfibrillar regions continued to form crystallites sequentially at 134.6 °C, which clearly confirmed the fractional crystallization of P(L-2H3MB). In our knowledge, this unique fractional crystallization has not been reported yet, of the component in miscible blend, which crystallized first under little confinement. This work provided a new viewpoint and understanding of the relationship between fractional crystallization and microstructures in crystalline/crystalline blends.
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高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Hang Su,Shuo Huang,Xin Gao,He Bai,Haopeng Zhang,Long Li,Lei Zhao,Hongyan Yue
Highly efficient recognition and detection of chiral molecules with similar structures are of great significance in the fields of medicine and biochemistry. In this study, strobili fibers of the plane tree were carbonized at high temperatures to prepare hollow chiral helical carbon tubes (HCT). Subsequently, l-threonine (l-Thr) was nanoassembled on the HCT surface (l-Thr@HCT) through hydrogen bonding and electrostatic interactions. Benefiting from the synergistic effect of conductive HCT with inherent chirality and l-Thr with abundant chiral sites, the electrode demonstrates a satisfied recognition efficiency of 3.20 for the cysteine (Cys) enantiomer. The l-Thr@HCT/GCE electrode exhibits a lower affinity toward l-Cys than d-Cys, thereby facilitating the diffusion of l-Cys to the electrode surface and exhibiting excellent selectivity for l-Cys. Under the optimal conditions, the electrode has a high sensitivity of 1.74 μA·mM–1 for l-Cys with a low detection limit of 8.58 μM (S/N = 3). Moreover, the electrode has good repeatability, reproducibility, and stability. This electrode will have a potential clinical application in chiral sensing.
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高影响因子
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