MICROCHEMICAL JOURNAL
·
2025
·
IF 5.1
Shu-zhen Xiao,Jie Wang,Jia Liu,Yin Wu,Chang-Zhao Wang,Zhong-ping Yin,Xin-chen Shangguan,Da-yong Peng
A novel fluorescent labeling reagent 4-(2-(9-ethyl-9H-carbazol-3-yl)-1H-phenanthro[9,10-d] imidazol-1-yl) butyl-4-methylbenzene sulfonate (CPIOTs) was designed, synthesized and applied in this study for the determination of triterpene acids using high-performance liquid chromatography with a fluorescence detector (HPLC-FLD). The derivatives of CPIOTs demonstrated exceptional stability and fluorescence properties, with maximum excitation and emission wavelengths at 311 nm and 398 nm, respectively. Calibration curves under optimized conditions displayed outstanding linear responses, as evidenced by correlation coefficients (R 2 ) exceeding0.9996. The detection and quantification limits were in the range of 0.098–0.160 ng/ml and 0.354–0.528 ng/ml, respectively. Therefore, CPIOTs proved to be a successful tool for detecting trace levels of oleanolic acid (OA) and ursolic acid (UA) in loquat leaves samples.
研究领域:
植物化学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
PROCESS BIOCHEMISTRY
·
2015
·
IF 2.516
Xiang Zou,Jing Yang,Xu Tian,Meijing Guo,Zhenghua Li,Yunzheng Li
Polymalic acid (PMA) is a water-soluble biopolymer with many attractive properties for pharmaceutical applications. Its monomer, l -malic acid, is a potential C4 platform chemical, which is widely used in the food industry. In this study, a new strain with a high PMA yield from xylose was isolated and identified as Aureobasidium pullulans based on the morphological and phylogenetic analyzes. This strain produced PMA from xylose at a comparable or higher rate than glucose, and PMA produced from xylose had a similar molecular weight to that produced from glucose. A high final PMA titer of 80.4 g/L (91.2 g/L of malic acid after hydrolysis) was achieved using fed-batch fermentation with xylose in a 5-L fermentor at a PMA productivity of 0.52 g/L h. Corncob hydrolysate could be better utilized producing 28.6 g/L of PMA (or 32.4 g/L malic acid) in batch fermentation. PMA was further characterized for its chemical structure. This strain can be used to produce PMA and malic acid from xylose and lignocellulosic biomass hydrolysates.
研究领域:
生物化学
·
工业微生物学
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产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR MODELING
·
2017
·Vol. 23
·期 8
·1-11
·
IF 1.425
Sun Jiachen,Dong Shengjie,Wu Yueting,Zhao Hui,Li Xia,Gao Wenyuan
It is known that inhibiting α-amylase, an important enzyme in digestion of starch and glycogen, is a useful strategy for treating disorders in carbohydrate uptake. Two natural components distributed in many fruits and plants, oleanolic acid and ursolic acid, are endowed with important pharmacological activities and wide therapeutic possibilities. Until now, only a tiny fraction of their applications have been identified and exploited. Our in vitro inhibition studies demonstrated that oleanolic acid and ursolic acid non-competitively inhibit the activity and function of human salivary α-amylase. The molecular simulations revealed that oleanolic acid and ursolic acid interact with amino acid residues within the binding pocket of human salivary α-amylase, among which the side chain of Arg195 and Asp 197 was supposed to be important in imparting the inhibitory activity of triterpenoids. The present work will provide meaningful information for future development of functional drugs for the treatment of disorders in carbohydrate metabolism.
This work is valuable for providing a deeper insight into the interaction mechanism of oleanolic acid and ursolic acid with α-amylase
研究领域:
药理学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MEDICINAL CHEMISTRY RESEARCH
·
2019
·Vol. 28
·期 8
·1212-1222
·
IF 1.72
Sheng Li-xin,Huang Jia-yan,Liu Chun-mei,Zhang Ju-zheng,Cheng Ke-guang
A total of 25 targeted hydrogen sulfide donor–pentacyclic triterpene hybrids were designed, synthesized and evaluated on the basis of inspiring reports about hydrogen sulfide donor molecules and oleanolic acid derivatives on anti-tumor activity. The results revealed that only some hybrids ( 10a , 10b , 12a , 12b , 13a , and 15b ) showed moderate anti-proliferation activity against K562 cell line. It indicated that oleanane-type, ( R )-lipoic acid and TBZ groups were much more favorable to the anti-proliferation activity. Furthermore, C-3 OH was more beneficial than C-28/29 COOH in the oleanane-type to the antitumor activity of the batch of ( R )-lipoic acid derivatives. And among them, only compound 13a exhibited moderate anti-proliferation activity against both K562 and K562/ADR cell lines, while it exhibited no anti-proliferation activity against BEL-7402 and L-O2 cell lines. Therefore, it suggested that it was not suitable for hybridization of hydrogen sulfide donors attached to oleanolic acid, ursolic acid and glycyrrhetinic acid in the field of anti-tumor.
研究领域:
药物化学
·
肿瘤学
·
分子生物学
·
药理学
·
天然产物化学
✓ 已验证
DOI
高影响因子
EUROPEAN FOOD RESEARCH AND TECHNOLOGY
·
2014
·Vol. 239
·期 5
·827-835
·
IF 1.387
Wang Panxue,Li Aixia,Dong Mei,Fan Mingtao
The aim of this study was to purify a malolactic enzyme (MLE) from Oenococcus oeni ( O. oeni ) strain and determine its properties in detail. O. oeni SD-2a was cultivated in the ATB broth supplemented with 7 g/L l -malic acid for harvesting the cells. After harvest, the cells were washed and disrupted for purification of MLE. MLE was purified from the supernatant of the disrupted cells through protamine sulfate precipitation, anion exchange chromatography and gel filtration chromatography. The purified MLE was identified using mass spectrometry. The MLE was purified by 43-fold with a yield of 0.42 % and possessed a specific activity of 419.2 U/mg. The purified enzyme with a nominal molecular mass of 59 kDa and a theoretical p I of 4.76 exhibited a maximum enzyme activity at 35 °C and pH 6.0, which retained over 50 % of its initial activity in the presence of 14 % (v/v) ethanol. Mn 2+ was proven to be the most effective divalent cation to promote enzyme activity. Under the conditions of temperature 30 °C and pH 6.0, the K
m and V
max of MLE on l -malic acid were 12.5 × 10 −3 M and 43.86 μmol/(min × mg), respectively. Moreover, the purified enzyme exhibited a higher stability with 0.1 M NaCl in addition and had a half-life of 30 days at 4 °C.
研究领域:
微生物学
·
酶学
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2023
·
IF 8.8
Hanqing Wu,Linlu Zheng,Liangbin Lin,Hongyu Guo,Fafu Yang
Fluorescent sensors had been extensively applied on sensing various biomolecules effectively, but no fluorescent sensor for oleanolic acid was presented up to now. In this work, the first fluorescent sensor for oleanolic acid was designed and synthesized based on o-phenyl-bridged bis-tetraphenylimidazole ( PTPI ). PTPI was prepared by bridging two tetraphenylimidazole units and o-phenylenediamine via Schiff-base condensation in yield of 86%. PTPI showed high sensing selectivity for oleanolic acid among 26 biomolecules and ions. The blue fluorescence at 482 nm was enhanced by 4.5 times after sensing oleanolic acid in aqueous media. The fluorescence sensing ability of PTPI for oleanolic acid maintained stable in pH = 5–9. The detecting limitation was as low as 0.032 μM. The detecting mechanism was clarified as 1:1 binding stoichiometry by fluorescence Job’s plot, mass spectrometry, 1 H nuclear magnetic resonance and fourier transform infrared spectroscopy. The detecting ability of PTPI for oleanolic acid was successfully used for paper test and real samples of grapes and Kuding tea with recoveries in the range of 96.0%-106.0%, indicating the good application potential for on-site detecting oleanolic acid in real samples of fruits and food.
研究领域:
分析化学
·
生物化学
✓ 已验证
DOI
PubMed
高影响因子
FLUID PHASE EQUILIBRIA
·
2014
·
IF 2.241
Ye Yuan,Yixin Leng,Hui Shao,Chunxiang Huang,Kai Shan
The solubility of dl -malic acid in water, ethanol and ethanol + water mixtures was investigated by a static analytical technique using the acid–base titration method at temperatures ranging from 298.15 to 333.15 K. The experimental results indicated that the solubility of dl -malic acid in the binary solvent mixtures increases with increasing temperature and decreases with increasing mass fraction of ethanol. The measured solid–liquid equilibrium (SLE) data were correlated by the modified Apelblat, λh and van’t Hoff equations. The calculated solubility demonstrated good agreement with the experimental data. It was found that the modified Apelblat equation could give the best correlation results, and subsequently used to derive the standard enthalpy, entropy and Gibbs energy change of solution of dl -malic acid in ethanol + water binary mixtures.
研究领域:
化学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
CARBONATES AND EVAPORITES
·
2018
·Vol. 34
·期 3
·1131-1139
·
IF 0.947
Li Zhenxuan,Xiao Jiangtian,Huang Lidong,Xu Defu,Liu Dagang,Sun Xiaowen,Yu Luji,Wu Hongsheng
Succinic acid and l -malic acid are known to affect calcite dissolution/crystallization due to their tendency to adsorb on calcite’s surface. Taking into account the structural similarity among succinic acid, l -malic acid, and d -malic acid, a comparative study of their adsorption behavior on calcite was investigated for clarifying their adsorption mechanism. Kinetic results showed that l -malic acid adsorption reached equilibrium within 12 h, while succinic acid required 48 h. Results from the pH effect study showed that the strength of surface complex of succinic acid on calcite was weaker, even compared to its aqueous complex with Ca 2+ ion. Alternately, l -malic acid exhibited a much stronger surface complex strength, even compared to its aqueous complex with Ca 2+ ion. The adsorption isotherm results indicated that the saturated adsorption amount of l -malic acid was twice that of succinic acid, suggesting the surface complex of succinic acid may occupy a larger space on calcite surface compared to that of l -malic acid. Based on these results and those from previous studies, we proposed that succinic acid adsorption is through its two carboxyl groups binding to two adjacent surface sites (> Ca + ), and not only one. Also, l -malic acid adsorption occurs through one carboxyl group and one hydroxyl, which forms a “claw” on calcite surface. The similar adsorption behavior between l -malic acid and d -malic acid reinforces this proposition for l -malic acid adsorption mechanism. Our study will serve as good reference information to provide better understanding into the adsorption of other carboxylic acids on calcite.
研究领域:
地质学
·
化学
✓ 已验证
DOI
高影响因子
ENZYME AND MICROBIAL TECHNOLOGY
·
2016
·
IF 2.624
Lei Zhou,Wei Liu,Zhiqiang Xiong,Liqiang Zou,Junping Liu,Junzhen Zhong,Jun Chen
Polyphenoloxidase (PPO) plays an important role in the browning of vegetables, fruits and edible fungi. The effects of ultrasound, malic acid, and their combination on the activity and conformation of mushroom ( Agaricus bisporus ) PPO were studied. The activity of PPO decreased gradually with the increasing of malic acid concentrations (5–60 mM). Neither medium concentrations (10, 20, 30 mM) malic acid nor individual ultrasound (25 kHz, 55.48 W/cm 2 ) treatment could remarkably inactivate PPO. However, the inactivation during their combination was more significant than the sum of ultrasound inactivation and malic acid inactivation. The inactivation kinetics of PPO followed a first-order kinetics under the combination of ultrasound and malic acid. The conformation of combination treated PPO was changed, which was reflected in the decrease of α-helix, increase of β-sheet contents and disruption of the tertiary structure. Results of molecular microstructure showed that ultrasound broke large molecular groups of PPO into small ones. Moreover, combined treatment disrupted the microstructure of PPO and molecules were connected together.
研究领域:
食品科学
·
生物化学
✓ 已验证
DOI
高影响因子
COMBUSTION AND FLAME
·
2024
·
IF 5.8
Xueqin Liao,Jianzhong Liu,Zexu Li,Mengxia Sun
Aluminum (Al) particles are widely used in propellants, thermite and pyrotechnics. However, commonly used micro Al has drawbacks such as agglomeration, high ignition temperature and slow burning rate, making its energy potential not fully exploited in applications. Therefore, exploring pathways to enhance the combustion of Al particles has become the focus at present. Herein, L -malic acid (LMA) was used to corrode the surface of Al particles to obtain a sample (named LMAl) with an average specific surface area of 11.456 m 2 /g (corresponding to Al particles with a diameter of 194 nm). The particle size distribution of LMAl did not change significantly compared to pristine Al. The XPS results showed that a small amount of LMA and corrosion products remained on the surface of the LMAl particles. Thermal analysis tests showed that the thermal oxidation rate and efficiency of LMAl was dramatically higher than that of pristine Al. Compared with the pristine Al, the combustion characterization parameters of LMAl such as combustion intensity, ignition delay time, maximum combustion temperature, mass burning rate and combustion efficiency were all improved. This trend was maintained after blending the ammonium perchlorate (AP). The condensed combustion products (CCPs) of Al revealed a large number of agglomerates and unburned Al particles. While many broken particles and tentacle-like structures were found in the CCPs of LMAl. Overall, compared to Al, the combustion of LMAl is significantly enhanced. The thermal reaction and combustion behaviors of the two are quite different. This study provides new insights into improving the ignition and combustion of Al.
研究领域:
材料科学
·
燃烧学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL GEOLOGY
·
2020
·
IF 3.363
Weiyan Que,Bihe Wang,Feili Li,Xiujuan Chen,Hui Jin,Zanfang Jin
The accumulation of heavy metals by freshwater algae becomes more complex in the presence of dissolved organic matter but it is unclear how and to what extent. In this study, we comparatively assessed the effects of malic acid and citric acid on the bioaccumulation of Pb by Chlorella pyrenoidosa . A 6 h exposure experiment showed that adding organic acid (OA) to an algae–Pb binary system prolonged the adsorption equilibrium time and that the extended time was related to the concentration and number of carboxyl groups of the OA. A pseudo-second-order model fit the kinetic data well in the presence of OAs. The normality of carboxyl groups was negatively correlated with the bioaccumulation rate, k 2 , but positively correlated with the maximum bioaccumulation capacity, q max , of Pb following a linear equation, Y = 121.3x + 52.2, R 2 = 0.9877. Neither the Freundlich model nor the Langmuir model could fit the isotherm data in the presence of OA, suggesting that a new mechanism might exist. The quantitative relationship between bioaccumulated Pb and carboxyl group of OA indicated a stoichiometric relationship, which seemed to support the theory of a ternary complex of Pb, OA, and algal surface. Our results have added clarity to the current understanding of the accumulation of heavy metals by algae in freshwater ecosystems .
研究领域:
环境科学
·
水生生物学
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2015
·
IF 4.097
Guoxin Song,Chunli Xu,Baoxin Li
We report a method for visual differentiation between the l - and d -forms of mandelic acid (MA). It is based on the chirality of l -tartaric acid-capped gold nanoparticles ( l -TA-capped AuNPs, ca. 13 nm in diameter) that can be used as chiral selector for l - and d -forms of MA. On addition of l -MA to a solution of the l -TA-capped AuNPs, a color change from red to blue can be seen, while no color change is found on addition of d -MA. The chiral assay can be used to determine the enantiomeric excess of l -MA in the range from −100% to 100%. The effect can be detected with bare eyes and quantified by spectrophotometry. Notably, this method does not require the complicated chiral modification. The method excels by its sensitivity, low cost, good availability of materials, and its simplicity.
研究领域:
分析化学
·
纳米科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）