121-79-9Relevant academic research and scientific papers
Characterization of Aspergillus fumigatus CAS-21 tannase with potential for propyl gallate synthesis and treatment of tannery effluent from leather industry
Cavalcanti, Rayza Morganna Farias,Jorge, Jo?o Atílio,Guimar?es, Luis Henrique Souza
, (2018)
One of the tannase isoforms produced by the fungus Aspergillus fumigatus CAS-21 under submerged fermentation (SbmF) was purified 4.9-fold with a 10.2% recovery. The glycoprotein (39.1% carbohydrate content) showed an estimated molecular mass of 60?kDa. Optimum temperature and pH for its activity were 30–40?°C and 5.0, respectively. It showed a half-life (t50) of 60?min at 45 and 50?°C, and it was stable at pH 5.0 and 6.0 for 3?h. The tannase activity was insensitive to most salts used, but it reduced in the presence of Fe2(SO4)3 and FeCl3. On contrary, in presence of SDS, Triton-X100, and urea the enzyme activity increased. The Km value indicated high affinity for propyl gallate (3.61?mmol L?1) when compared with tannic acid (6.38?mmol L?1) and methyl gallate (6.28?mmol L?1), but the best Kcat (362.24?s?1) and Kcat/Km (56.78?s?1 mmol?1 L) were obtained for tannic acid. The purified tannase reduced 89 and 25% of tannin content of the leather tannery effluent generated by manual and mechanical processing, respectively, after 2-h treatment. The total phenolic content was also reduced. Additionally, the enzyme produced propyl gallate, indicating its ability to do the transesterification reaction. Thus, A. fumigatus CAS-21 tannase presents interesting properties, especially the ability to degrade tannery effluent, highlighting its potential in biotechnological applications.
Development of a tannase biocatalyst based on bio-imprinting for the production of propyl gallate by transesterification in organic media
Nie, Guangjun,Zheng, Zhiming,Jin, Wei,Gong, Guohong,Wang, Li
, p. 32 - 37 (2012)
A bio-imprinting technique was applied to activate tannase in order to enhance its biocatalytic activity. Specifically, the effects of three bio-imprinting methods (i.e. substrate imprinting, pH imprinting, and interfacial imprinting) on the activating factor of tannase were investigated. The results show that bio-imprinting methods can activate tannase remarkably, and they were combined to develop a tannase biocatalyst with a 40% conversion rate of substrate, 100-fold higher than that of the control. This approach can be used to construct an effective way to produce propyl gallate as well as to exploit readily available tannic acid. The immobilized bio-imprinted tannase can catalyze the synthesis of propyl gallate from tannic acid by transesterification in organic media. This work not only presents an effective means of making use of various tannic acid-rich agro-forestry residues, but also broadens the field of applications of the bio-imprinting technique.
Enhancement of transesterification-catalyzing capability of bio-imprinted tannase in organic solvents by cryogenic protection and immobilization
Nie, Guangjun,Chen, Zhen,Zheng, Zhiming,Jin, Wei,Gong, Guohong,Wang, Li,Yue, Wenjin
, p. 1 - 6 (2013)
Improvement of transesterification-catalyzing capability of bio-imprinted tannase is a crucial question of whether to be efficiently utilized in organic media. As for biotransformation of tannic acid to propyl gallate, bio-imprinting technique can dramatically enhance the transesterification-catalyzing capability of tannase. In this work, both cryogenic protection and immobilization were utilized to further improve its apparent catalytic capability in organic media. The results show that Triton-X-100, mannose, and magnesium ion all have a positive effect on cryogenic protection of the tannase. Particularly, combinational application of the three cryoprotectants increases its catalytic performance by 2.7-fold factor. Also, immobilization further elevates its catalytic capability by 2.1 folds. Noteworthily, the coupling application of immobilization and cryo-protection can cause the conversion rate of substrate of the bio-imprinted tannase to increase to a promising 70%. Consequently, it will be helpful to fully utilize tannase in organic phase.
Role of cyclic alkyl group in conformational instability of tannase
Nie, Guangjun,Zhao, Rui,Sun, Wuyue,Gao, Yu,Zhu, Xiangxiang,Zheng, Zhiming,Yue, Wenjin
, p. 78 - 81 (2016)
The conformational stability of enzyme has a crucial effect on its catalytic performance. The effects of six organic solvents with different structures on the conformational stability of tannase were studied using Fourier transform infrared spectroscopy in this work. This results indicated that the cyclic structure of organic solvent plays a negative role in the conformational stability of tannase. The alkyl group of organic solvent has an interaction with the groups of oxygen and nitrogen of tannase, and the interaction goes against the conformational stability. The findings potentially provide a deep insight into the relationship between the biocatalytic activity and conformational stability of enzymes and push the study on the interaction of enzyme with organic solvent.
Self-assembled tetramethyl cucurbit[6]uril-polyoxometalate nanocubes as efficient and recyclable catalysts for the preparation of propyl gallate
Li, Shuang,Xia, Wen,Zhang, Yunqian,Tao, Zhu
, p. 11895 - 11900 (2020)
The development of cucurbit[n]urils-polyoxometalate (Q[n]-POM) hybrids with the same microshape and nanoscale features is highly desirable, yet remains a great challenge. Herein, we design and synthesize a class of Q[n]-POM hybrids and tetramethyl cucurbit[6]uril-phosphomolybdic acid (TMeQ[6]-PMA) nanocubes (NCs) via a facile one-step self-assembly method, as heterogeneous acid catalysts for greatly boosting the catalysts in term of activity and stability for the esterification of gallic acid and n-propanol to propyl gallate (PG). The Fourier transform infrared (FTIR) spectroscopy reveals that the self-assembled mechanism of TMeQ[6]-PMA NCs based on the outer-surface interaction of Q[n]s. The temperature programmed desorption experiments with ammonia and FTIR analysis of the pre-adsorbed pyridine results confirm that the coexistence of medium and strong acid sites and a larger number of Lewis acid sites other than Br?nsted acidic sites on the catalyst surface. These new features make the as-prepared TMeQ[6]-PMA NCs exhibit a high PG conversion (95.6percent) and excellent stability, which epresents a better catalytic performance than other reported catalysts.
Thermodynamics of the hydrolysis of 3,4,5-trihydroxybenzoic acid propyl ester (n-propylgallate) to 3,4,5-trihydroxybenzoic acid (gallic acid) and propan-1-ol in aqueous media and in toluene
Tewari,Schantz,Rekharsky,Goldberg
, p. 171 - 185 (1996)
Equilibrium measurements at several temperatures between 293 K and 308 K have been performed on the tannase catalyzed reaction : 3,4,5-trihydroxybenzoic acid propyl ester(sln) + H2O(sln) = 3,4,5-trihydroxybenzoic acid(sln) + propan-1-ol(sln), where sln = aqueous phosphate buffer, aqueous acetate buffer, and toluene. The change in binding of the hydrogen ion ΔrN(H+) for this biochemical reaction in aqueous solution was calculated both from an equilibrium model for the biochemical reaction and from the dependence of the apparent equilibrium constant on pH. Calorimetric measurements were also performed for this biochemical reaction in aqueous phosphate and 2-(N-morpholino)ethanesulfonic acid (MES) buffers. Standard transformed thermodynamic quantities for the overall biochemical reaction as well as standard thermodynamic quantities for chemical reference reactions that involve specific chemical species have been calculated from the experimental results. It was found that the equilibrium yield of 3,4,5-trihydroxybenzoic acid propyl ester is significantly enhanced by carrying out the reaction in toluene rather than in the aqueous buffered solutions.
Synthesis of propyl gallate from tannic acid catalyzed by tannase from Aspergillus oryzae: Process optimization of transesterification in anhydrous media
Nie, Guangjun,Liu, Hui,Chen, Zhen,Wang, Peng,Zhao, Genhai,Zheng, Zhiming
, p. 102 - 108 (2012)
Improving the catalytic capability of enzyme is an important challenge of biocatalysis in organic medium. Optimization of organic reaction system and reaction mode can elevate the catalytic ability. In order to enhance the catalytic efficiency of tannase-catalyzed transesterification from tannic acid, process parameters of the reaction and reaction mode were optimized further to improve the conversion rate of substrate. The result showed that with hexane as solvent, a conversion rate of substrate, 75%, was achieved at 40 °C in 20 mL reaction mixture composed of 0.75% water and 7.5% n-propanol, and that semicontinuous catalysis was the most favorable for production of propyl gallate, its average production rate was 2.5-fold that of batch catalysis. By SCC, a noted computative conversion rate of approximate, 90%, was obtained. Thus, it is expected that this study may present an efficient and ecofriendly method for industrial production of PG.
Enhancement of propyl gallate yield in nonaqueous medium using novel cell-associated tannase of bacillus massiliensis
Aithal, Mahesh,Belur, Prasanna D.
, p. 445 - 455 (2013)
Enzymatic synthesis of propyl gallate in organic solvent was studied using cell-associated tannase (EC 3.1.1.20) of Bacillus massiliensis. Lyophilized biomass showing tannase activity was used as the biocatalyst. The effects of solvent, surfactant treatment, and bioimprinting on the propyl gallate synthesis were studied and subsequently optimized. Among various solvents, benzene followed by hexane was found to be the most favorable. Treatment of the biocatalyst with Triton X-100 at a lower concentration (0.2% w/v), before lyophilization, increased the propyl gallate yield by 24.5% compared to the untreated biocatalyst. The biocatalyst was imprinted with various concentrations of gallic acid and tannic acid. Biocatalyst imprinted with tannic acid showed 50% enhancement in the propyl gallate yield compared to the non-imprinted biocatalyst.
Potentiation of vasoconstrictor response and inhibition of endothelium-dependent vasorelaxation by gallic acid in rat aorta
Sanae, Fujiko,Miyaichi, Yukinori,Hayashi, Hisao
, p. 690 - 693 (2002)
In the isolated rat thoracic aorta, gallic acid potentiated the vasoconstrictor response to phenylephrine. The potentiation produced by gallic acid was absent in endothelium-denuded arteries. The potentiation was abolished by NG-nitro-L-arginine methyl ester, an inhibitor of nitric oxide synthesis, and slightly attenuated by an addition of L-arginine, while indomethacin or BQ610 had no effect. The potentiation of response to phenylephrine was not found for structural modifications of gallic acid, except for caffeic acid. Gallic acid also inhibited vasorelaxation induced by acetylcholine, sodium nitroprusside or prostacyclin, especially that by acetylcholine. The effect on vasorelaxation induced by acetylcholine was decreased by esterification of the carboxy group of gallic acid, and in the absence or by the methylation of the o-dihydroxy group. Caffeic acid inhibited the vasorelaxation, though the effect was smaller than that of gallic acid. These findings indicate that gallic acid produces a potentiation of contractile response and inhibition of vasorelaxant responses, probably through inactivation of nitric oxide (NO), in which endothelially produced NO is principally involved, and that the modification of functional groups of the gallic acid molecule abolishes the potentiation of contractile response and attenuates the inhibition of vasorelaxant responses.
Enzymatic propyl gallate synthesis in solvent-free system: Optimization by response surface methodology
Bouaziz, Ahlem,Horchani, Habib,Salem, Nadia Ben,Chaari, Ali,Chaabouni, Moncef,Gargouri, Youssef,Sayari, Adel
, p. 242 - 250 (2010)
The ability of a non-commercial immobilized Staphylococcus xylosus lipase to catalyze the esterification of propanol with gallic acid was investigated and the antioxidant as well as the antimicrobial activities of the ester formed were evaluated. The response surface methodology, based on a three variables Box-Behnken design (reaction temperature, enzyme amount and 1-propanol/gallic acid molar ratio), was used to optimize the experimental conditions of propylgallate synthesis. The maximum conversion yield (90% ±3.5) was obtained by using 400 IU of immobilized lipase and a propanol/gallic acid at a molar ratio of 160 at 52 °C. The obtained ester was characterized by spectroscopic methods, NMR and FTIR. The antioxidant activity of propyl gallate was evaluated and compared to the synthetic classical antioxidants, BHA and ascorbic acid, taken as references. In addition, the antimicrobial activity of the propyl gallate was tested against S. xylosus, Escherchia coli and Staphylococcus aureus using disc diffusion and macrodilution methods. Our results show that the synthesized propyl gallate ester presents a higher antioxidant and antimicrobial power than the parent gallic acid as well as the synthetic classical antioxidants.
