Kinetics of Enzymatic Synthesis of L-ascorbyl Acetate by Lipozyme TLIM and Novozym 435

Dong-Hao Zhang,Ya-Qiong Li,Chao Li,Yv-Qin Lv,Yang-L 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.1

L-ascorbyl acetate was synthesized through lipase-catalyzed esterification using Lipozyme TLIM and Novozym 435. Four solvents, including methanol, ethanol,acetonitrile, and acetone were investigated for the reaction,and acetone and acetonitrile were found to be suitable reaction media. The influences of several parameters such as water activity (aw), substrate molar ratio, enzyme loading,and reaction temperature on esterification of Lascorbic acid were systematically and quantitatively analyzed. Through optimizing the reaction, lipase-catalyzed esterification of L-ascorbic acid gave a maximum conversion of 99%. The results from using Lipozyme TLIM and Novozym 435 as biocatalysts both showed that aw was an important factor for the conversion of L-ascorbic acid. The effect of pH value on lipase-catalyzed L-ascorbic acid esterification in acetone was also investigated. Furthermore,results from a kinetic characterization of Lipozyme TLIM were compared with those for Novozym 435, and suggested that the maximum reaction rate for Lipozyme TLIM was greater than that for Novozym 435, while the enzyme affinity for substrate was greater for Novozym 436.

Effects of L-tryptophan, Fructan, and Casein on Reducing Ammonia, Hydrogen Sulfide, and Skatole in Fermented Swine Manure

Q.K. Sheng,Z.J. Yang,H.B. Zhao,X.L. Wang,J.F. Guo 아세아·태평양축산학회 2015 Animal Bioscience Vol.28 No.8

The effects of daily dietary Bacillus subtilis (Bs), and adding L-tryptophan, fructan, or casein to fecal fermentation broths were investigated as means to reduce the production of noxious gas during manure fermentation caused by ammonia, hydrogen sulfide (H2S), and 3-methylindole (skatole). Eighty swine (50.0±0.5 kg) were equally apportioned to an experimental group given Bs in daily feed, or a control group without Bs. After 6 weeks, fresh manure was collected from both groups for fermentation studies using a 3×3 orthogonal array, in which tryptophan, casein, and fructan were added at various concentrations. After fermentation, the ammonia, H2S, L-tryptophan, skatole, and microflora were measured. In both groups, L-tryptophan was the principle additive increasing skatole production, with significant correlation (r = 0.9992). L-tryptophan had no effect on the production of ammonia, H2S, or skatole in animals fed Bs. In both groups, fructan was the principle additive that reduced H2S production (r = 0.9981). Fructan and Bs significantly interacted in H2S production (p = 0.014). Casein was the principle additive affecting the concentration of ammonia, only in the control group. Casein and Bs significantly interacted in ammonia production (p = 0.039). The predominant bacteria were Bacillus spp. CWBI B1434 (26%) in the control group, and Streptococcus alactolyticus AF201899 (36%) in the experimental group. In summary, daily dietary Bs reduced ammonia production during fecal fermentation. Lessening L-tryptophan and increasing fructan in the fermentation broth reduced skatole and H2S.

Effects of L-tryptophan, Fructan, and Casein on Reducing Ammonia, Hydrogen Sulfide, and Skatole in Fermented Swine Manure

Sheng, Q.K.,Yang, Z.J.,Zhao, H.B.,Wang, X.L.,Guo, J.F. Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.8

The effects of daily dietary Bacillus subtilis (Bs), and adding L-tryptophan, fructan, or casein to fecal fermentation broths were investigated as means to reduce the production of noxious gas during manure fermentation caused by ammonia, hydrogen sulfide ($H_2S$), and 3-methylindole (skatole). Eighty swine ($50.0{\pm}0.5kg$) were equally apportioned to an experimental group given Bs in daily feed, or a control group without Bs. After 6 weeks, fresh manure was collected from both groups for fermentation studies using a $3{\times}3$ orthogonal array, in which tryptophan, casein, and fructan were added at various concentrations. After fermentation, the ammonia, $H_2S$, L-tryptophan, skatole, and microflora were measured. In both groups, L-tryptophan was the principle additive increasing skatole production, with significant correlation (r = 0.9992). L-tryptophan had no effect on the production of ammonia, $H_2S$, or skatole in animals fed Bs. In both groups, fructan was the principle additive that reduced $H_2S$ production (r = 0.9981). Fructan and Bs significantly interacted in $H_2S$ production (p = 0.014). Casein was the principle additive affecting the concentration of ammonia, only in the control group. Casein and Bs significantly interacted in ammonia production (p = 0.039). The predominant bacteria were Bacillus spp. CWBI B1434 (26%) in the control group, and Streptococcus alactolyticus AF201899 (36%) in the experimental group. In summary, daily dietary Bs reduced ammonia production during fecal fermentation. Lessening L-tryptophan and increasing fructan in the fermentation broth reduced skatole and $H_2S$.

Effect of Rare Earth Elements on Proliferation and Fatty Acids Accumulation of 3T3-L1 Cells

He, M.L.,Yang, W.Z.,Hidari, H.,Rambeck, W.A. Asian Australasian Association of Animal Productio 2006 Animal Bioscience Vol.19 No.1

The present study including two experiments was designed to determine the effect of media containing different rare earth elements (REE) on proliferation and fatty acids accumulation in 3T3-L1 cell cultures. In Experiment 1, 3T3-L1 preadipocytes in 96-well plates ($1.5{\times}10^4cells/ml$) were cultured with Dulbecco's modified Eagle's medium (DMEM) containing 10% fetal bovine serum (FBS) for 24 h. Then the media were changed to the following 10 different media for 48 h: DMEM containing 10% FBS for the control; the above media containing $5{\mu}M$, $10{\mu}M$ or $15{\mu}M$ of $LaCl_3$, $CeCl_3$ or the mixture of these REE chlorides. The proliferation rate of the cells was measured and compared by a non-isotope method-XTT method. In Experiment 2 the cells in 24-well plates ($1.5{\times}10^4cells/ml$) were cultured in DMEM containing 10% FBS for 7 days until confluent and then were changed to above DMEM containing dexamethasone, methyl-isobutylxanthine and insulin (DMI) for two days. Afterwards the media were changed to the 10 different media with REE supplements as in Experiment 1 and cultured for 6 days. The cells were then harvested for fatty acids analysis by gas chromatography. It was found that supplementation of La (5, 10 and $15{\mu}M$), Ce ($5{\mu}M$ and $15{\mu}M$) and the mixture REE (5, 10 and $15{\mu}M$) stimulated (p<0.05) the proliferation of 3T3-L1 preadipocytes (Experiment 1). In the differentiating 3T3-L1 cells supplementation of La ($5{\mu}M$ and $10{\mu}M$), Ce ($5{\mu}M$) and the mixture REE ($5{\mu}M$ and $15{\mu}M$) decreased (p<0.05) the concentration of monounsaturated fatty acids (MUFA) per $10^5cells$, while the supplementation of La ($5{\mu}M$), Ce ($5{\mu}M$) and the mixture REE ($15{\mu}M$) increased (p<0.05) the ratio of saturated fatty acids (SFA) to MUFA. These results indicate that the supplementation of REE to the media may affect proliferation, differentiation and lipogenesis rates of 3T3-L1 cells. However, the effect may depend upon the level or type of REE applied.

Heat Shock Protein Augmentation of Angelica gigas Nakai Root Hot Water Extract on Adipogenic Differentiation in Murine 3T3-L1 Preadipocytes

Lumbera, Wenchie Marie L.,Cruz, Joseph dela,Yang, Seung-Hak,Hwang, Seong Gu Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.3

There is a high association of heat shock on the alteration of energy and lipid metabolism. The alterations associated with thermal stress are composed of gene expression changes and adaptation through biochemical responses. Previous study showed that Angelica gigas Nakai (AGN) root extract promoted adipogenic differentiation in murine 3T3-L1 preadipocytes under the normal temperature condition. However, its effect in heat shocked 3T3-L1 cells has not been established. In this study, we investigated the effect of AGN root hot water extract in the adipogenic differentiation of murine 3T3-L1 preadipocytes following heat shock and its possible mechanism of action. Thermal stress procedure was executed within the same stage of preadipocyte confluence (G0) through incubation at $42^{\circ}C$ for one hour and then allowed to recover at normal incubation temperature of $37^{\circ}C$ for another hour before AGN treatment for both cell viability assay and Oil Red O. Cell viability assay showed that AGN was able to dose dependently (0 to $400{\mu}g/mL$) increase cell proliferation under normal incubation temperature and also was able to prevent cytotoxicity due to heat shock accompanied by cell proliferation. Confluent preadipocytes were subjected into heat shock procedure, recovery and then AGN treatment prior to stimulation with the differentiation solution. Heat shocked preadipocytes exhibited reduced differentiation as supported by decreased amount of lipid accumulation in Oil Red O staining and triglyceride measurement. However, those heat shocked preadipocytes that then were given AGN extract showed a dose dependent increase in lipid accumulation as shown by both evaluation procedures. In line with these results, real-time polymerase chain reaction (RT-PCR) and Western blot analysis showed that AGN increased adipogenic differentiation by upregulating heat shock protection related genes and proteins together with the adipogenic markers. These findings imply the potential of AGN in heat shock amelioration among 3T3-L1 preadipocytes through heat shock factor and proteins augmentation and enhanced adipogenic marker expression.

Dipyrenylcalix[4]arene—A Fluorescence-Based Chemosensor for Trinitroaromatic Explosives

Lee, Young Hoon,Liu, Hongguang,Lee, Jin Yong,Kim, Sang Hoon,Kim, Sung Kuk,Sessler, Jonathan L.,Kim, Yang,Kim, Jong Seung WILEY-VCH Verlag 2010 Chemistry Vol.16 No.20

<P>A new chemosensor-based approach to the detection of nitroaromatics is described. It involves the analyte-induced quenching of excimer emission of a dipyrenyl calix[4]arene (L). The chemical and photophysical properties of the complexes formed between L and mono-, di-, and trinitrobenzene, and di- and trinitrotoluene were studied in acetonitrile and chloroform by using <SUP>1</SUP>H NMR, UV/Vis, and fluorescence spectroscopy. Fluorescence spectroscopy revealed that the trinitroaromatics engendered the largest response among the various substrates tested, with the sensitivity for these analytes being correspondingly high. Quantitative analysis of the fluorescence titration profile generated from the titration of L with TNT provided evidence that this particular functionalized calix[4]arene receptor allows for the detection of TNT down to the low ppb level in CH<SUB>3</SUB>CN. A single-crystal X-ray diffraction analysis revealed that in the solid state the complex L⋅TNT consists of a supramolecular crystalline polymeric structure, the formation of which appears to be driven by intermolecular π–π interactions between two pyrene units and a TNT molecule held at a distance of 3.2–3.6 Å, as well as by intra- and intermolecular hydrogen-bonds among the amide linkages. Nevertheless, the changes in the <SUP>1</SUP>H NMR, UV/Vis, and fluorescence spectrum, including sharp color changes, are ascribed to a charge-transfer interaction arising from complementary π–π overlap between the pyrene subunits and the bound trinitroaromatic substrates. A number of ab initio calculations were also carried out and, considered in concert, they provide further support for the proposed charge-transfer interactions, particularly in the case of L⋅TNT.</P> <B>Graphic Abstract</B> <P>How to find TNT! A new chemosensor-based approach for the detection of nitrated aromatics is described. It involves the analyte-induced quenching of excimer emission of a dipyrenyl-calix[4]-arene (L; see graphic). In the solid state, the complex L⋅TNT consists of a supramolecular crystalline polymeric structure, the formation of which appears to be driven by intermolecular π–π interactions between two pyrene units and a TNT molecule held at a distance of 3.2–3.6 Å. <img src='wiley_img_2010/09476539-2010-16-20-CHEM200903439-content.gif' alt='wiley_img_2010/09476539-2010-16-20-CHEM200903439-content'> </P>

The Effect of Trifluoroethanol on Tyrosinase Activity and Conformation: Inhibition Kinetics and Computational Simulations

L체, Z. R.,Shi, L.,Wang, J.,Park, D.,Bhak, J.,Yang, J. M.,Park, Y. D.,Zhou, H. W.,Zou, F. HUMANA PRESS INC 2010 Applied biochemistry and biotechnology Vol.160 No.7

Pressure-induced dramatic changes in organic–inorganic halide perovskites

Lü,, Xujie,Yang, Wenge,Jia, Quanxi,Xu, Hongwu Royal Society of Chemistry 2017 Chemical Science Vol.8 No.10

<▼1><P>We summarise cutting-edge discoveries and provide insights into the important theme of halide perovskites using pressure as a tuning tool.</P></▼1><▼2><P>Organic–inorganic halide perovskites have emerged as a promising family of functional materials for advanced photovoltaic and optoelectronic applications with high performances and low costs. Various chemical methods and processing approaches have been employed to modify the compositions, structures, morphologies, and electronic properties of hybrid perovskites. However, challenges still remain in terms of their stability, the use of environmentally unfriendly chemicals, and the lack of an insightful understanding into structure–property relationships. Alternatively, pressure, a fundamental thermodynamic parameter that can significantly alter the atomic and electronic structures of functional materials, has been widely utilized to further our understanding of structure–property relationships, and also to enable emergent or enhanced properties of given materials. In this perspective, we describe the recent progress of high-pressure research on hybrid perovskites, particularly regarding pressure-induced novel phenomena and pressure-enhanced properties. We discuss the effect of pressure on structures and properties, their relationships and the underlying mechanisms. Finally, we give an outlook on future research avenues in which high pressure and related alternative methods such as chemical tailoring and interfacial engineering may lead to novel hybrid perovskites uniquely suited for high-performance energy applications.</P></▼2>

Inhibition of tyrosinase by fumaric acid: Integration of inhibition kinetics with computational docking simulations

Gou, L.,Lee, J.,Yang, J.M.,Park, Y.D.,Zhou, H.M.,Zhan, Y.,Lu, Z.R. Elsevier 2017 International Journal of Biological Macromolecules Vol.105 No.3

Fumaric acid (FA), which is naturally found in organisms, is a well known intermediate of the citric acid cycle. We evaluated the effects of FA on tyrosinase activity and structure via enzyme kinetics and computational simulations. FA was found to be a reversible inhibitor of tyrosinase and its induced mechanism was the parabolic non-competitive inhibition type with IC<SUB>50</SUB>=13.7+/-0.25mM and K<SUB>islope</SUB>=12.64+/-0.75mM. We newly established the equation for the dissociation constant (K<SUB>islope</SUB>) for the parabolic inhibition type in this study. Kinetic measurements and spectrofluorimetry studies showed that FA induced regional changes in the active site of tyrosinase. One possible binding site for FA was identified under the condition without L-DOPA. The computational docking simulations further revealed that FA can interact with HIS263 and HIS85 at the active site. Furthermore, four important hydrogen bonds were found to be involved with the docking of FA on tyrosinase. Our study provides insight into the mechanism by which dicarboxylic acids such as FA inhibit tyrosinase. By inhibiting tyrosinase and its central role in pigment production, FA is a potential natural antipigmentation agent.

Effect of Garlic Oil on Fatty Acid Accumulation and Glycerol-3-Phosphate Dehydrogenase Activity in Differentiating Adipocytes

He, M.L.,Yang, W.Z.,You, J.S.,Chaves, A.V.,Mir, P.S.,Benchaar, C.,McAllister, T.A. Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.12

Garlic oil (GAR, Allium sativum L.) has been studied as a feed additive to improve animal production performance and decrease methane emission in ruminants. The present study was designed to determine the possible effect of GAR on fatty acid composition and accumulation in animal fat tissue using a cell model. 3T3-L1 preadipocytes at $2{\times}10^{4}\;mL^{-1}$ were seeded to 24-well plates and allowed to proliferate to reach confluence. The cells were then treated with media containing 0, 2.5, 5, 10, 20 and 40 $\mu{g}$ $mL^{-1}$ of GAR during the differentiation period for 8 days. Media containing dexamethasone, methyl-isobutylxanthine and insulin was applied during the first 2 days of the early differentiation period. On day 8 sub-sets of the wells were stained with oil red-O and the remaining cells were harvested for determination of glycerol-3-phosphate dehydrogenase [EC 1.1.1.8] (GPDH) activity (n = 6) and cellular fatty acid concentration (n = 6). It was found that supplementation of GAR increased (p<0.05) the ratio of monounsaturated fatty acids/saturated fatty acids in the adipocytes and showed inhibitory effect (p<0.05) on the post-confluent proliferation. With relative low dosage, GAR (5-20 $\mu{g}$ $mL^{-1}$) increased (p<0.05) the GPDH activity without affecting the cellular fatty acid concentration, while a high dosage (40 $\mu{g}$ $mL^{-1}$) inhibited (p<0.05) fatty acid accumulation and decreased GPDH activity. Supplementation of GAR had an effect on cell post-confluent proliferation, differentiation and fatty acid accumulation. However, the effect may be diverse and depends on the dose applied.