CHEMICAL ENGINEERING & TECHNOLOGY
·
2016
·Vol. 39
·期 10
·1867-1874
·
IF 2.385
Jun Mei,Zhirong Chen,Shenfeng Yuan,Jianyong Mao,Haoran Li,Hong Yin
A kinetic study on isophorone synthesis via self-condensation of supercritical acetone catalyzed by aqueous KOH in a tubular flow reactor was conducted. The intention was to improve the isophorone selectivity, with the main approach to reduce the by-products higher-boiling than isophorone. A higher isophorone selectivity was obtained with increased reaction temperature. The structures of main products were determined by gas chromatography-mass spectrometry and nuclear magnetic resonance analysis. The key reaction pathways and a corresponding kinetic model were proposed. The fitted apparent activation energies indicated the reason of isophorone selectivity improvement in that high temperature favors reversion of reversible by-products.
研究领域:
化学工程
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催化反应
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有机化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
·
2021
·Vol. 101
·期 12
·5163-5171
·
IF 3.639
Jiali Huang,Yu-Jing Lu,Chenglong Guo,Shanshan Zuo,Jin-Lin Zhou,Wing-Leung Wong,Baohua Huang
BACKGROUND The pericarp of citrus in rutaceae is rich in flavonoids that may possess diverse biological activities. Some citrus flavonoids have been used as natural bitterness inhibitors; however, many citrus flavonoid analogues that possess merit taste amelioration functions have not been reported with respect to utilization in food industry. RESULTS The effects of 12 citrus flavonoids on the inhibition of the bitter taste of naringin, quinine hydrochloride and stevioside were evaluated both by a sensory panel and electronic tongue analysis. Among the flavonoid compounds evaluated, both neohesperidin dihydrochalcone (NHDC) and neodiosmin were identified to show an excellent bitterness inhibition effect on all three bitterness vehicles tested. The results of the electronic tongue evaluation also showed that the addition of neodiosmin, NHDC or hesperidin dihydrochalcone-7-o-glucoside (HDC-7-G) was able to reduce significantly the bitterness response value of quinine hydrochloride, which is consistent with the sensory panel evaluation. Structure–activity relationship analysis found that the 7-linked neohesperidosyloxy group in the A-ring of the citrus flavonoid skeleton has the best bitterness inhibition effect. In addition, a ternary mixture of NHDC, neodiosmin and naringin, and neodiosmin/β-cyclodextrin was formulated and it demonstrated, for the first time in the flavor improvement of citrus fruit wine, an enhancement of sweetness and a reduction of bitter taste. CONCLUSION Twelve citrus flavonoids were found to inhibit the bitter taste of naringin, quinine hydrochloride and stevioside. With respect to the structure–activity relationship analysis, it was found that the 7-linked neohesperidosyloxy group in the A-ring of the citrus flavonoid skeleton possessed the best bitterness inhibition effect. © 2021 Society of Chemical Industry
研究领域:
食品科学
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植物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Royal Society Open Science
·
2018
·Vol. 5
·期 5
·
IF 2.504
Yucui Hou,Shuhang Ren,Muge Niu,Weize Wu
The selective hydrogenation of isophorone (3,5,5-trimethyl-2- cyclohexen-1-one) to produce 3,3,5-trimethylcyclohexanone (TMCH), an important organic solvent and pharmaceutical intermediate, is of significance in industry. However, the over-hydrogenation to produce the by-product 3,3,5-trimethylcyclohexanol causes issues. Up to now, it is still a challenge to hydrogenate isophorone to TMCH with high selectivity. In this work, we found that Lewis acids could inhibit the hydrogenation of C=O bond on isophorone, thus greatly improving the selectivity towards TMCH. In addition, added solvents like supercritical CO2 also had a positive impact on the selectivity. Both the conversion and selectivity could be increased to more than 99% when suitable Lewis acid and solvent were employed. Nevertheless, Lewis acid also exhibited some inhibition on the hydrogenation of the C=C bond of isophorone. Hence, a relatively weak Lewis acid, ZnCl2, is suitable for the selective hydrogenation.
研究领域:
化学工程
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催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
·
IF 3.141
Feng Zhou,Hongchen Liu,Zhenghui Wen,Boyu Zhang,Guangwen Chen
Pseudoionone (PI) is a well-known and widely used precursor for ionones, which have been substantially applied in flavor, fragrance and pharmaceutical industry. The phase behavior in respect to the synthesis of PI was investigated through the combination of simulation and experiment to better understand the reaction process. A continuous-flow microreactor for efficient synthesis of PI was introduced. Various conditions (temperature, molar ratio of acetone to citral, citral concentration, NaOH concentration, residence time, and volume ratio of ethanol to water) were investigated to improve the synthesis process of PI. The condensation reaction preformed in the tubular and packed-bed microreactor under continuous-flow conditions was compared. Using a continuous-flow microreactor, PI could be efficiently synthesized from citral and a high PI yield of 93.8% could be achieved under the optimized conditions. Furthermore, a simplified kinetic model was developed to provide guidance for the synthesis of PI.
研究领域:
化学工程
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香料与制药工业
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2020
·Vol. 25
·期 4
·858
·
IF 3.267
Xiaojuan Liu,Yue Wang,Yezhi Chen,Shuting Xu,Qin Gong,Chenning Zhao,Jinping Cao,Chongde Sun
O-methylation of flavonoids is an important modification reaction that occurs in plants.O-methylation contributes to the structural diversity of flavonoids, which have several biological and pharmacological functions. In this study, anO-methyltransferase gene (CrOMT2) was isolated from the fruit peel ofCitrus reticulata, which encoding a multifunctionalO-methyltransferase and could effectively catalyze the methylation of 3’-, 5’-, and 7-OH of flavonoids with vicinal hydroxyl substitutions. Substrate preference assays indicated that this recombinant enzyme favored polymethoxylated flavones (PMF)-type substrates in vitro, thereby providing biochemical evidence for the potential role of the enzyme in plants. Additionally, the cytotoxicity of the methylated products from the enzymatic catalytic reaction was evaluated in vitro using human gastric cell lines SGC-7901 and BGC-823. The results showed that the in vitro cytotoxicity of the flavonoids with the unsaturated C2-C3 bond was increased after being methylated at position 3’. These combined results provide biochemical insight regarding CrOMT2 in vitro and indicate the in vitro cytotoxicity of the products methylated by its catalytic reaction.Keywords:citrus;flavonoids;O-methyltransferase;bioactivity;cytotoxicity
研究领域:
植物生物化学
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药理学
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分子生物学
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细胞生物学
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 54
·34343-34354
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IF 3.361
Liling Wang,Yuchuan Qin,Yanbin Wang,Yifeng Zhou,Bentong Liu,Minge Bai,Xiaoqing Tong,Ru Fang,Xubo Huang
The inhibition mechanism of two homoisoflavonoids from Ophiopogon japonicus including methylophiopogonanone A (MO-A) and methylophiopogonanone B (MO-B) on tyrosinase (Tyr) was studied by multiple spectroscopic techniques and molecular docking. The results showed that the two homoisoflavonoids both inhibited Tyr activity via a reversible mixed-inhibition, with a half inhibitory concentration (IC50) of (10.87 ± 0.25) × 10−5 and (18.76 ± 0.14) × 10−5 mol L−1, respectively. The fluorescence quenching and secondary structure change of Tyr caused by MO-A and B are mainly driven by hydrophobic interaction and hydrogen bonding. Molecular docking analysis indicated that phenylmalandioxin in MO-A and methoxy in MO-B could coordinate with a Cu ion in the active center of Tyr, and interacted with amino acid Glu322 to form hydrogen bonding, occupying the catalytic center to block the entry of the substrate and consequently inhibit Tyr activity. This study may provide new perspectives on the inhibition mechanism of MO-A and MO-B on Tyr and serve a scientific basis for screening effective Tyr inhibitors.
研究领域:
生物化学
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药理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Marine Drugs
·
2021
·Vol. 19
·期 12
·652
·
IF 5.118
Liping Wang,Yiwen Hou,Rong Wang,Qi Pan,Debao Li,Han Yan,Zuyue Sun
This study investigates the inhibitory effect of astaxanthin (AST) on testosterone-induced benign prostatic hyperplasia (BPH) in rats. Except for the sham operation, BPH model rats were randomly assigned to five groups: the BPH model control rats, AST-treated BPH model rats (20 mg/kg, 40 mg/kg, and 80 mg/kg), and epristeride (EPR)-treated BPH model rats. After treatment, as compared with the BPH model control rats, the prostate and ventral prostate weights of the AST-treated rats decreased, while there was a marked decline in the 80 mg/kg AST-treated rats. The same effect was also observed in the prostate index and ventral prostate index. The proliferation characteristics of epithelia observed in the BPH model control group were gradually alleviated in the AST-treated rats. As compared with the BPH model control rats, lower epithelial thicknesses of prostates and fewer secretory granules in epithelia were observed in the AST-treated rats. The superoxide dismutase (SOD) activity of prostates increased in all the AST-treated rats with a significant increase in the 40 mg/kg and 80 mg/kg AST-treated rats. The testosterone (T) and dihydrotestosterone (DHT) levels of prostates in the AST-treated groups were lower than those in the BPH model control group, and a significant decline was found in the T level of prostates in the 40 g/kg and 80 mg/kg AST-treated rats and the DHT level of prostates in the 40 mg/kg AST-treated rats. These results indicate that AST might have an inhibitory effect on T-induced BPH in rats, possibly due to SOD activity regulation and T and DHT levels.Keywords:astaxanthin;benign prostatic hyperplasia;pharmacodynamics;SOD activity
研究领域:
药理学
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泌尿外科
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内分泌学
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DOI
PubMed
高影响因子
EUROPEAN POLYMER JOURNAL
·
2023
·
IF 6
Hongjian Gu,Cheng Liu,Qian Liu,Yu Zhang,Meng Wang,Xi Chen,Yousi Chen,Jinyan Wang,Xigao Jian
A series of poly(bisphthalazinone ether sulfone ketone)s with pendant phenyl groups (POPESKs) were synthesized via aromatic nucleophilic substitution polycondensation. The thermal degradation mechanism of POPESKs was determined investigated by TG-FTIR. The T g s of POPESKs range from 296 to 326 °C and the storage modulus retention is up to 46.1 % at 290 °C. POPESKs have good solubility in dichloroethane, chloroform, tetrachloroethane, N -methyl-2-pyrrolidone and pyridine, and exhibit good film-forming property. The tensile strength, tensile modulus, and tensile elongation of POPESK films are 85–96 MPa, 1.34–1.86 GPa, and 8.9–11.6 %, respectively. Meanwhile, the polymer films exhibit the high light transmittance of up to 83 % at 800 nm and its water contact angle are in the range of 82.3–94.3°. Its superior overall performance shows great potential in aerospace, petrochemical and energy applications.
研究领域:
材料科学
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2023
·Vol. 46
·期 19
·2300326
·
IF 3.1
Ling-Li Wang,Na Liu,Shuang Hu,Rong-Rong Xing,Run-Qin Wang,Li Yang,Xuan Chen
A simple and rapid instantaneous nebulization dispersive liquid-phase microextraction method was developed, and combined with high-performance liquid chromatography for determination of the contents of seven analytes in traditional Chinese medicines. In this study, using the sprinkler device to achieve instantaneous synchronous dispersion and extraction, only one spray can rapidly achieve the concentration and enrichment of seven kinds of chalcone and isoflavones. The key factors affecting the extraction efficiency were optimized including the type and volume of extractant, the pH and salt concentration of the sample phase, and the number of dispersion. Under the optimal conditions, the enrichment factor of the target analytes ranged from 103.1 to 180.9, with good linearity and correlation coefficients above 0.9970. The limits of detection ranged from 0.02 to 0.15 ng/mL, with good accuracy (recoveries 91.1 to 108.9%) and precision (relative standard deviations 1.5–7.1%). This method has short extraction time (2 s), low organic solvent consumption and high enrichment effect, so it has a wide application prospects.
研究领域:
分析化学
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中药学
✓ 已验证
DOI
PubMed
高影响因子
BIOTECHNOLOGY AND APPLIED BIOCHEMISTRY
·
2022
·Vol. 70
·期 2
·697-706
·
IF 2.724
Shijin Wu,Bijiao Wang,Hongde Yan
Asymmetric reduction of ( R )-carvone and ketoisophorone by an engineered ene-reductase from Galdieria sulphuraria (GsOYE) combined with glucose dehydrogenase for NADPH regeneration were studied. A semi-rational protein engineering was used to enhance the activity and selectivity of GsOYE. Upon the sequence alignment and molecular docking results, two amino acid residues at positions 66 and 270 were selected as saturation mutation sites. Finally, a single substitution variant of GsOYE-N270A with complete conversion (100%) and diastereoselectivity (de p >99%) for reduction of ( R )-carvone and a double substitution variant GsOYE-Y66P/N270H with improved stereoselectivity for reduction of ketoisophorone were obtained.
研究领域:
生物化学
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蛋白质工程
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催化
·
酶学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
·
2020
·
IF 4.335
Haiyun Peng,Yu Zhang,Yang Zhu,Guisheng Deng
We report the synthesis of 4-(furan-2-yl)-3,4-dihydro-2H-pyrrol-2-one derivatives. In this approach, two core structures, the furan ring and 3,4-dihydro-2H-pyrrol-2-one, are constructed via silver(I)-catalyzed cascade cyclization/cyclopropanation/ring-cleavage/nucleophilic substitution reaction of enynones with enamines. A reasonable mechanism has been proposed. This method possesses some advantages such as high chemoselectivity, mild reaction conditions, simple operation, and short reaction time.
研究领域:
有机化学
·
合成化学
✓ 已验证
DOI
PubMed
高影响因子
Food & Function
·
2015
·Vol. 7
·期 1
·409-416
·
IF 2.791
Kaige Ji,Yudan Zhao,Tianhong Yu,Zhuoyi Wang,Hao Gong,Xin Yang,Yang Liu,Kun Huang
Parkinson's disease (PD) is one of the most common neurodegenerative diseases. Lewy bodies that are formed by the aggregated α-synuclein are a major pathological feature of PD. Salvia miltiorrhiza has been used as food and as a traditional medicine for centuries in China, with tanshinone I (TAN I) and tanshinone IIA (TAN IIA) as its major bioactive ingredients. Here, we investigated the effects of TAN I and TAN IIA on α-synuclein aggregation both in vitro and in a transgenic Caenorhabditis elegans PD model (NL5901). We demonstrated that TAN I and TAN IIA inhibited the aggregation of α-synuclein as demonstrated by the prolonged lag time and the reduced thioflavin-T fluorescence intensity; TAN I and TAN IIA also disaggregated preformed mature fibrils in vitro. Moreover, the presence of TAN I or TAN IIA affected the secondary structural transformation of α-synuclein from unstructured coils to β-sheets, and alleviated the membrane disruption caused by aggregated α-synuclein in vitro. Besides, the immuno-dot-blot assay indicated that TAN I and TAN IIA reduce the formation of oligomers and fibrils. We further found that TAN I and TAN IIA extended the life span of NL5901, a strain of transgenic C. elegans that expresses human α-synuclein, possibly by attenuating the aggregation of α-synuclein. Taken together, our results suggested that TAN I and TAN IIA may be explored further as potential candidates for the prevention and treatment of PD.
研究领域:
神经科学
·
药理学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
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