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Functional characterization of caffeic acid

Fengyan WU, Zhenying WU, Aiguo YANG, Shanshan JIANG, Zeng-Yu WANG, Chunxiang FU

《农业科学与工程前沿（英文）》 2018年 第5卷 第1期   页码 98-107 doi: 10.15302/J-FASE-2017198

摘要： Caffeic acid -methyltransferase (COMT) is a crucial enzyme that mainly methylates phenylpropanoid -hydroxyl of C in the biosynthesis of syringyl lignin in angiosperms. A putative , named as , was isolated from switchgrass ( ), a C warm-season dual-purpose forage and bioenergy crop. Our results showed that recombinant PvCOMT1 enzyme protein catalyzed the methylation of 5-OH coniferyl alcohol, 5-OH coniferaldehyde (CAld5H) and 5-OH ferulic acid. Further studies indicate that CAld5H can dominate COMT-mediated reactions by inhibiting the methylation of the other substrates. Transgenic switchgrass plants generated by an RNAi approach were further employed to study the function of in internode lignification. A dramatic decrease in syringyl lignin units coupled with an obvious incorporation in 5-OH guaiacyl lignin units were observed in the COMT-RNAi transgenic plants. However, the constitutive suppression of COMT in switchgrass plants altered neither the pattern of lignin deposition along the stem nor the anatomical structure of internodes. Consistent with the biochemical characterization of PvCOMT1, a significant decrease in sinapaldehyde was found in the COMT-RNAi transgenic switchgrass plants, suggesting that CAld5H could be the optimal intermediate in the biosynthesis syringyl lignin.

关键词： biofuel crop     caffeic acid O-methyltransferase     forage     lignin     Panicum virgatum     switchgrass     transgenic plant    

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利用异源酶组合构建酿酒酵母中咖啡酸的生物合成 Article

刘岚清, 刘宏, 张伟, 姚明东, 李炳志, 刘夺, 元英进

《工程（英文）》 2019年 第5卷 第2期   页码 287-295 doi: 10.1016/j.eng.2018.11.029

摘要：

微生物中构建植物源天然产物的生物合成面临着许多挑战，尤其是当需要表达与激活植物源细胞色素P450酶的时候。通过从几种细菌中筛选HpaB和HpaC两种酶，本文在酿酒酵母中构建了具有活性的4-羟基苯乙酸3-羟化酶（4 HPA3H），它可以发挥植物源细胞色素P450酶的相似作用，用于生产咖啡酸。在与一个共同的酪氨酸氨裂解酶（TAL）协同作用下，不同的异源HpaB酶和HpaC酶组合在将底物L-酪氨酸转化为目标产物咖啡酸上展现出不同能力。以铜绿假单胞菌的HpaB酶和肠沙门氏菌的HpaC酶的异源酶组合可生产最高咖啡酸产量，摇瓶培养下可达到（289.4 ± 4.6）mg·L−1。酵母底盘细胞与异源酶的相容性得到了有效的改善，咖啡酸的产量比初始值提高了40倍。铜绿假单胞菌HpaB酶中黄素腺嘌呤二核苷酸（FAD）结合域周围的6个关键氨基酸残基与其他细菌来源的HpaB酶有明显区别，可能在影响酶活性方面起关键作用。综上，我们建立了一种有效的方法来构建高效的酵母系统用于合成非天然羟基苯丙烷类化合物。

关键词： 酿酒酵母     咖啡酸     异源酶     细胞色素P450酶     合成生物学    

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Prediction of selected biodiesel fuel properties using artificial neural network

Solomon O. GIWA,Sunday O. ADEKOMAYA,Kayode O. ADAMA,Moruf O. MUKAILA

《能源前沿（英文）》 2015年 第9卷 第4期   页码 433-445 doi: 10.1007/s11708-015-0383-5

摘要： Biodiesel is an alternative fuel to replace fossil-based diesel fuel. It has fuel properties similar to diesel which are generally determined experimentally. The experimental determination of various properties of biodiesel is costly, time consuming and a tedious process. To solve these problems, artificial neural network (ANN) has been considered as a vital tool for estimating the fuel properties of biodiesel, especially from its fatty acid (FA) composition. In this study, four ANNs have been designed and trained to predict the cetane number (CN), flash point (FP), kinematic viscosity (KV) and density of biodiesel using ANN with logsig and purelin transfer functions in the hidden layer of all the networks. The five most prevalent FAs from 55 feedstocks found in the literature utilized as the input parameters for the model are palmitic, stearic, oleic, linoleic and linolenic acids except for density network with a sixth parameter (temperature). Other FAs that are present in the biodiesels have been considered based on the number of carbon atom chains and the level of saturation. From this study, the prediction accuracy and the average absolute deviation of the networks are CN (96.69%; 1.637%), KV (95.80%; 1.638%), FP (99.07%; 0.997%) and density (99.40%; 0.101%). These values are reasonably better compared to previous studies on empirical correlations and ANN predictions of these fuel properties found in literature. Hence, the present study demonstrates the ability of ANN model to predict fuel properties of biodiesel with high accuracy.

关键词： biodiesel     fuel properties     artificial neural network     fatty acid     prediction    

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Investigation of the effects of humic acid and H 2 O 2 on the photocatalytic degradation of atrazine

Chao QIN, Shaogui YANG, Cheng SUN, Jia ZHOU, Manjun ZHAN, Rongjun WANG, Huanxing CAI,

《环境科学与工程前沿（英文）》 2010年 第4卷 第3期   页码 321-328 doi: 10.1007/s11783-010-0238-6

摘要： A solution of atrazine in a TiO suspension, an endocrine disruptor in natural water, was tentatively treated by microwave-assisted photocatalytic technique. The effects of mannitol, oxygen, humic acid, and hydrogen dioxide on the photodegradation rate were explored. The results could be deduced as follows: the photocatalytic degradation of atrazine fits the pseudo-first-order kinetic well with = 0.0328 s, and ·OH was identified as the dominant reactant. Photodegradation of atrazine was hindered in the presence of humic acid, and the retardation effect increased as the concentration of humic acid increased. HO displayed a significant negative influence on atrazine photocatalysis efficiency. Based on intermediates identified with gas chromatography-mass spectrometry (GC-MS) and Liquid chromatography-mass spectrometry (LC-MS/MS) techniques, the main degradation routes of atrazine are proposed.

关键词： atrazine     retardation effect     photocatalysis     TiO2    

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PGUS1 hybrid nanoflower through protein-inorganic self-assembly, and its application in glycyrrhetinic acid3-O-mono-β-D-glucuronide preparation

Tian Jiang, Yuhui Hou, Tengjiang Zhang, Xudong Feng, Chun Li

《化学科学与工程前沿（英文）》 2019年 第13卷 第3期   页码 554-562 doi: 10.1007/s11705-019-1834-z

摘要： Glycyrrhetinic acid 3- -mono- -D-glucuronide (GAMG), an important pharmaceutical intermediate and functional sweetener, has broad applications in the food and medical industries. A green and cost-effective method for its preparation is highly desired. Using site-directed mutagenesis, we previously obtained a variant of -glucuronidase from Li-3 (PGUS1), which can specifically transform glycyrrhizin (GL) into GAMG. In this study, a facile method was established to prepare a CaHPO -PGUS1 hybrid nanoflower for enzyme immobilization, based on protein-inorganic hybrid self-assembly. Under optimal conditions, 1.2 mg of a CaHPO -PGUS1 hybrid nanoflower precipitate with 71.2% immobilization efficiency, 35.60 mg∙g loading capacity, and 118% relative activity was obtained. Confocal laser scanning microscope and scanning electron microscope results showed that the enzyme was encapsulated in the CaHPO -PGUS1 hybrid nanoflower. Moreover, the thermostability of the CaHPO -PGUS1 hybrid nanoflower at 55°C was improved, and its half-life increased by 1.3 folds. Additionally, the CaHPO -PGUS1 hybrid nanoflower was used for the preparation of GAMG through GL hydrolysis, with the conversion rate of 92% in 8 h, and after eight consecutive runs, it had 60% of its original activity.

关键词： β-glucuronidase     enzyme-inorganic hybrid nanoflower     biotransformation     glycyrrhizin     glycyrrtinic acid 3-O-mono-β-D-glucuronide    

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A magnetic adsorbent based on salicylic acid-immobilized magnetite nano-particles for pre-concentration

Hossein Abdolmohammad-Zadeh, Arezu Salimi

《化学科学与工程前沿（英文）》 2021年 第15卷 第2期   页码 450-459 doi: 10.1007/s11705-020-1930-0

摘要： In this research, an eco-friendly magnetic adsorbent based on Fe O /salicylic acid nanocomposite was fabricated using a facile one-pot co-precipitation method. The crystalline and morphological characterization of the prepared nanocomposite was performed by field emission scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The nanocomposite was employed as a magnetic solid-phase extraction agent for separation of Cd(II) ions from synthetic solutions. Some experimental factors affecting the extraction efficiency were investigated and optimized. Following elution with acetic acid (pH 3.5), the pre-concentrated analyte was quantified by flame atomic absorption spectrometry. In optimal conditions, a linear calibration graph was achieved in the concentration range of 0.2‒30 ng·mL with a determination coefficient ( ) of 0.9953. The detection limit, the enhancement factor, inter- and intra-day relative standard deviations (for six consecutive extractions at the concentration level of 10 ng·mL ) were 0.04 ng·mL , 100, 2.38% and 1.52%, respectively. To evaluate the accuracy of the method, a certified reference material (NIST SRM 1643e) was analyzed, and there was a good agreement between the certified and the measured values. It was successfully utilized to determine cadmium in industrial wastewater samples and the attained relative recovery values were between 96.8% and 103.2%.

关键词： cadmium     magnetic solid-phase extraction     Fe3O4 nanoparticles     Fe3O4/salicylic acid nanocomposite     flame atomic absorption spectrometry    

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On the monolayer dispersion behavior of Co3O4 on HZSM-5 support: designing applicable

《化学科学与工程前沿（英文）》 2023年 第17卷 第11期   页码 1741-1754 doi: 10.1007/s11705-023-2332-x

摘要： Based on monolayer dispersion theory, Co3O4/ZSM-5 catalysts with different loadings have been prepared for selective catalytic reduction of nitrogen oxides by ammonia. Co3O4 can spontaneously disperse on HZSM-5 support with a monolayer dispersion threshold of 0.061 mmol 100 m–2, equaling to a weight percentage around 4.5%. It has been revealed that the quantities of surface active oxygen (O2–) and acid sites are crucial for the reaction, which can adsorb and activate NOx and NH3 reactants effectively. Below the monolayer dispersion threshold, Co3O4 is finely dispersed as sub-monolayers or monolayers and in an amorphous state, which is favorable to generate the two kinds of active sites, hence promoting the performance of ammonia selective catalytic reduction of nitrogen oxide. However, the formation of crystalline Co3O4 above the capacity is harmful to the reaction performance. 4% Co3O4/ZSM-5, the catalyst close to the monolayer dispersion capacity, possesses the most abundant active O2– species and acidic sites, thereby demonstrating the best reaction performance in all the samples. It is proposed the optimal Co3O4/ZSM-5 catalyst can be prepared by loading the capacity amount of Co3O4 onto HZSM-5 support.

关键词： Co3O4/ZSM-5     NOx-SCR by NH3     monolayer dispersion threshold effect     surface acid sites     surface active O2– anions    

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Chemical deactivation of V

Xiaodong WU, Wenchao YU, Zhichun SI, Duan WENG

《环境科学与工程前沿（英文）》 2013年 第7卷 第3期   页码 420-427 doi: 10.1007/s11783-013-0489-0

摘要： V O -WO /TiO catalyst was poisoned by impregnation with NH Cl, KOH and KCl solution, respectively. The catalysts were characterized by X-ray diffraction (XRD), inductively coupled plasma (ICP), N physisorption, Raman, UV-vis, NH adsorption, temperature-programmed reduction of hydrogen (H -TPR), temperature-programmed oxidation of ammonia (NH -TPO) and selective catalytic reduction of NO with ammonia (NH -SCR). The deactivation effects of poisoning agents follow the sequence of KCl>KOH>>NH Cl. The addition of ammonia chloride enlarges the pore size of the titania support, and promotes the formation of highly dispersed V=O vanadyl which improves the oxidation of ammonia and the high-temperature SCR activity. K ions are suggested to interact with vanadium and tungsten species chemically, resulting in a poor redox property of catalyst. More importantly, potassium can reduce the Br?nsted acidity of catalysts and decrease the stability of Br?nsted acid sites significantly. The more severe deactivation of the KCl-treated catalyst can be mainly ascribed to the higher amount of potassium resided on catalyst.

关键词： V2O5-WO3/TiO2     potassium chloride     poisoning     reducibility     acid sites    

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Preparation of P

Wenjiang LI, Fei XIE, Dongxu HUA, Chunli ZHANG, Chen DAI, Zhenyun YU, Meizhou QI, Shaojun YU

《化学科学与工程前沿（英文）》 2011年 第5卷 第3期   页码 314-317 doi: 10.1007/s11705-010-0573-y

摘要： Silica hollow microspheres containing phosphorous have been prepared by a sol-gel/emulsion method which uses tetraethoxysilane (TEOS) as the precursor for the SiO and phosphoric acid (H PO ) as the precursor for P O . The hollow structure forms an emulsion system which is composed of an oil phase (kerosene, sorbitan monooleate (Span 80)) and an aqueous phase (a viscous sol solution of ethanol, TEOS and H PO ). Some of the phosphorous remains in the final silica shell structure even after calcination at 650°C. The hollow structure of the P O -SiO (silicophosphate) was characterized by X-ray diffraction (XRD), polarized optical microscopy (POM), scanning electron microscopy (SEM), nitrogen adsorption measurement and Fourier transform infrared spectroscopy (FTIR).

关键词： P2O5-SiO2     hollow microspheres     sol-gel/emulsion     phosphoric acid    

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Is atmospheric oxidation capacity better in indicating tropospheric O formation?

《环境科学与工程前沿（英文）》 2022年 第16卷 第5期 doi: 10.1007/s11783-022-1544-5

摘要：

● This study summarizes and evaluates different approaches that indicate O3 formation.

关键词： O3     AOC     O3 formation regime    

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Availability of wind energy resource potential for power generation at Jos, Nigeria

O. O. Ajayi, R. O. Fagbenle, J. Katende, J. O. Okeniyi

《能源前沿（英文）》 2011年 第5卷 第4期   页码 376-385 doi: 10.1007/s11708-011-0167-5

摘要： The objective of this study was to assess the potential viability of the wind resource potential in Jos, Plateau state, Nigeria for power generation. The monthly mean wind speeds that span from 1987 to 2007 were employed to statistically analyze the monthly, annual and seasonal potentials of the wind energy resources at the site. Besides, the results were employed together with two models of wind energy conversion system to simulate the likely average output power. The outcome showed that Jos was suitable as a site for wind farm projects of varying sizes and that MW·h to GW·h of electricity is likely to be produced per period of months, seasons and years. The average wind speed range at the site was also estimated to be between 6.7 and 11.8 m/s across the months, years and seasons.

关键词： green electricity     renewable resources     Weibull statistics     Jos     Nigeria    

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Selective oxidation of o -nitrotoluene to o -nitrobenzaldehyde with metalloporphyrins as biomimetic catalysts

Xinling WANG, Yuanbin SHE,

《化学科学与工程前沿（英文）》 2009年 第3卷 第4期   页码 453-456 doi: 10.1007/s11705-009-0167-8

摘要： Selective oxidation of -nitrotoluene to -nitrobenzaldehyde with metalloporphyrins as biomimetic catalysts was studied. The peripheral substituent around porphyrin rings and various process parameters of NaOH concentration, reaction temperature, reaction time and oxygen pressure all affect the selectivity of -nitrobenzaldehyde. Further, 82.0% selectivity of -nitrobenzaldehyde was achieved under the optimum conditions: 1.0×10mol•L of T(-NO)PPFeCl catalyst, 2.5mol•L of NaOH, 0.2mol•L of -nitrotoluene, 45°C and 2.0MPa for 6h.

关键词： -nitrobenzaldehyde     temperature     biomimetic     selectivity     pressure    

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Sulfonic acid-functionalized mesoporous silica catalyst with different morphology for biodiesel production

《化学科学与工程前沿（英文）》 2022年 第16卷 第8期   页码 1198-1210 doi: 10.1007/s11705-021-2133-z

摘要： Sulfonic acid functionalized mesoporous silica based solid acid catalysts with different morphology were designed and fabricated. The synthesized materials were characterized by various physicochemical and spectroscopic techniques like scanning electron microscope-energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller surface area, thermogravimetric analysis and n-butylamine acidity. The shape of catalysts particles plays an important role in its activity. The sulfonic acid functionalized mesoporous silica catalysts of spherical shape and the cube shape were assessed for catalytic activity in biodiesel production. The catalytic biodiesel production reaction over the catalysts were studied by esterification of free fatty acid, oleic acid with methanol. The effect of various reaction parameters such as catalyst concentration, acid/alcohol molar ratio, catalyst amount, reaction temperature and reaction time on catalytic activity were investigated to optimize the conditions for maximum conversion. It was sulfonated cubic shape mesoporous silica which exhibited better activity as compared to the spherical shape silica catalysts. Additionally, the catalyst was regenerated and reused up to three cycles without any significant loss in activity. The present catalysts exhibit superior performance in biodiesel production and it can be used for the several biodiesel feedstock’s that are rich in free fatty acids.

关键词： solid acid catalyst     mesoporous silica     sulfonic acid     biodiesel     esterification     oleic acid    

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Rh2O3/hexagonal CePO4 nanocatalysts for N2O decomposition

Huan Liu, Zhen Ma

《化学科学与工程前沿（英文）》 2017年 第11卷 第4期   页码 586-593 doi: 10.1007/s11705-017-1659-6

摘要： Hexagonal CePO nanorods were prepared by a precipitation method and hexagonal CePO nanowires were prepared by hydrothermal synthesis at 150 °C. Rh(NO ) was then used as a precursor for the impregnation of Rh O onto these CePO materials. The Rh O supported on the CePO nanowires was much more active for the catalytic decomposition of N O than the Rh O supported on CePO nanorods. The stability of both catalysts as a function of time on stream was studied and the influence of the co-feed (CO , O , H O or O /H O) on the N O decomposition was also investigated. The samples were characterized by N adsorption-desorption, inductively coupled plasma optical emission spectroscopy, X-ray diffraction, transmission electron microscopy, X-ray photoelectron microscopy, hydrogen temperature-programmed reduction, oxygen temperature-programmed desorption, and CO temperature-programmed desorption in order to correlate the physicochemical and catalytic properties.

关键词： Rh2O3     CePO4     N2O decomposition    

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Amino acid promoted hydrogen battery system using Mn-pincer complex for reversible CO hydrogenation toformic acid

《能源前沿（英文）》 2022年 第16卷 第5期   页码 697-699 doi: 10.1007/s11708-022-0843-7

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标题 作者 时间 类型 操作

Functional characterization of caffeic acid

Fengyan WU, Zhenying WU, Aiguo YANG, Shanshan JIANG, Zeng-Yu WANG, Chunxiang FU

期刊论文

利用异源酶组合构建酿酒酵母中咖啡酸的生物合成

刘岚清, 刘宏, 张伟, 姚明东, 李炳志, 刘夺, 元英进

期刊论文

Prediction of selected biodiesel fuel properties using artificial neural network

Solomon O. GIWA,Sunday O. ADEKOMAYA,Kayode O. ADAMA,Moruf O. MUKAILA

期刊论文

Investigation of the effects of humic acid and H 2 O 2 on the photocatalytic degradation of atrazine

Chao QIN, Shaogui YANG, Cheng SUN, Jia ZHOU, Manjun ZHAN, Rongjun WANG, Huanxing CAI,

期刊论文

PGUS1 hybrid nanoflower through protein-inorganic self-assembly, and its application in glycyrrhetinic acid3-O-mono-β-D-glucuronide preparation

Tian Jiang, Yuhui Hou, Tengjiang Zhang, Xudong Feng, Chun Li

期刊论文

A magnetic adsorbent based on salicylic acid-immobilized magnetite nano-particles for pre-concentration

Hossein Abdolmohammad-Zadeh, Arezu Salimi

期刊论文

On the monolayer dispersion behavior of Co3O4 on HZSM-5 support: designing applicable

期刊论文

Chemical deactivation of V

Xiaodong WU, Wenchao YU, Zhichun SI, Duan WENG

期刊论文

Preparation of P

Wenjiang LI, Fei XIE, Dongxu HUA, Chunli ZHANG, Chen DAI, Zhenyun YU, Meizhou QI, Shaojun YU

期刊论文

Is atmospheric oxidation capacity better in indicating tropospheric O formation?

期刊论文

Availability of wind energy resource potential for power generation at Jos, Nigeria

O. O. Ajayi, R. O. Fagbenle, J. Katende, J. O. Okeniyi

期刊论文

Selective oxidation of o -nitrotoluene to o -nitrobenzaldehyde with metalloporphyrins as biomimetic catalysts

Xinling WANG, Yuanbin SHE,

期刊论文

Sulfonic acid-functionalized mesoporous silica catalyst with different morphology for biodiesel production

期刊论文

Rh2O3/hexagonal CePO4 nanocatalysts for N2O decomposition

Huan Liu, Zhen Ma

期刊论文

Amino acid promoted hydrogen battery system using Mn-pincer complex for reversible CO hydrogenation toformic acid

期刊论文