INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY
·
2019
·Vol. 55
·期 4
·1531-1538
·
IF 2.281
Yangping Ding,Bingcan Chen,Huayi Suo,Huarong Tong
Summary Theaflavin-3,3′-digallate (TFDG) is the main product formed by oxidative condensation between (−)-Epigallocatechin-3-gallate (EGCG) and (−)-Epicatechin-3-gallate (ECG). Some sub-products, such as homo- and hetero-oligomers of EGCG and ECG, are also produced simultaneously, which significantly decreases the yield of TFDG. In general, the optimum temperature for TFDG synthesis is 20 °C below which can reduce its generation resulting in the coexistence of a large amount of unreacted substrates (ECG and EGCG). Therefore, a higher possibility of increasing the formation of TFDG could be achieved if a suitable synthetic method can be developed at a low temperature. Our results showed that simultaneous dropwise addition of both EGCG and ECG could markedly enhance the content of TFDG at ice bath. Using such technique, the production of TFDG increased by 47.60% as compared to the group synthesised under the optimum temperature. The absorbance of TFDG at 278 nm is 2.36 times higher than that of ECG with equimolar concentration. Therefore, a rapid, simple and accurate calculation method of TFDG yield was developed via the spectral correlation. Based on the counting method, the yield of TFDG was 30.58% by using the novel synthetic method of TFDG.
研究领域:
食品科学
·
植物化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2016
·
IF 3.138
Shicheng Lei,Minhao Xie,Bing Hu,Li Zhou,Yi Sun,Muhammad Saeeduddin,Hongcheng Zhang,Xiaoxiong Zeng
In the present study, pear polyphenol oxidase (PPO) was purified, immobilized and applied for the synthesis of theaflavin-3,3′-digallate (TF3). Firstly, PPO of pear ( Pyrus bretschneideri Rehd cv. Huangguan) was purified 24.36-fold in specific activity with a recovery of 6.77% by sequential use of precipitation with 70% saturated ammonium sulfate and chromatography of DEAE-Sepharose Fast Flow column. The purified pear PPO, found to be a dimer of identical subunits of molecular mass 35 kDa, was then successfully immobilized onto Fe 3 O 4 /chitosan nanoparticles via glutaraldehyde coupling reaction. Finally, TF3 was effectively synthesized by applying the immobilized PPO as biocatalyst with epicatechin gallate (ECG) and epigallocatechin-3- O -gallate (EGCG) as substrates, and the maximum yield of TF3 was 42.23% based on the amount of ECG added. In addition, the immobilized enzyme still remained 85% of its initial ability after successive usage of 8 cycles and could be stored for 30 days with less loss of activity. All the results suggest that the developed procedure is quite useful and has great potential for synthesis of TF3 and other theaflavins.
研究领域:
食品科学
·
酶工程
·
植物学
✓ 已验证
DOI
PubMed
高影响因子
PHYTOMEDICINE
·
2025
·
IF 8.3
Xu Dong,Jianyin Miao,Ling Wu,Ziyu Kong,Zenghui Liu,Diyi Jia,Qingqing Zhai,Dan Zhang,Yan Xu
Background Diabetes patients face an elevated wound infection susceptibility and delayed healing processes. Currently, no existing literature has reported on the effect and mechanism of theaflavin-3, 3’-digallate nanoparticles (TFDG NPS) and TFDG NPS@hydrogels on diabetic wounds. Purpose Given that the treatment options for diabetic wound are limited, the aim of this study is to develop an innovative therapeutic approach to address diabetic wounds. Methods The TFDG NPS were prepared using ionic cross-linking, and they were then characterized. The biocompatibility of the TFDG NPS and TFDG NPS@hydrogel was assessed using a Cell Counting Kit-8 (CCK-8) assay and live/dead staining on HK-2 cells in vitro . Diabetic ICR mice were induced through intraperitoneal injection of streptozocin (STZ). They were then subjected to the creation of two full-thickness wounds on their dorsal areas. The effect and mechanism of the TFDG NPS and TFDG NPS@hydrogel on wound healing in diabetic mice were evaluated using a histological analysis, a western blot analysis, and molecular docking. Results The optimal TFDG NPS proportion was found to be TFDG:Gelatin (Gel):Chitosan (CS) = 2:1:1. Images photographed using a transmission electron microscope (TEM) revealed that the TFDG NPS appeared spherical, with a diameter of approximately 140 ± 20 nm. The favorable bio-compatibility of the TFDG NPS and TFDG NPS@hydrogel was confirmed using cell experiments. Animal studies demonstrated that both the TFDG NPS and TFDG NPS@hydrogel enhanced collagen fiber accumulation and new blood vessel density, reduced F4/80 infiltration, and upregulated the expression levels of TGF-β1, SMAD3, Collagen I, and α-SMA. The potential mechanism may involve activation of the TGF-β1/SMAD3 pathway, stimulating the secretion of Collagen I and α-SMA, and thereby facilitating wound closure in diabetic mice. The molecular docking results confirmed a high affinity between TFDG and TGF-β1/SMAD3. Conclusion TFDG NPS and TFDG NPS@hydrogel promoted wound closure in diabetic mice through the TFG-β1/SMAD3 pathway, thus exhibiting promising therapeutic potential for diabetic wound treatment.
研究领域:
医学
·
生物材料学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers in Bioengineering and Biotechnology
·
2024
·
IF 4.3
Chen Zhiyong,Wei Yingxian,Liang Likun,Wang Xu,Peng Fangfei,Liang Yiying,Huang Xin,Yan Kaiqi,Gao Yunxia,Li Kangjing,Huang Xiaoman,Jiang Xinglu,Chen Wenxia
Objectives: To study the ability of theaflavin-3,3’-digallate (TF3)/ethanol solution to crosslink demineralized dentin collagen, resist collagenase digestion, and explore the potential mechanism.Methods: Fully demineralized dentin blocks were prepared using human third molars that were caries-free. Then, these blocks were randomly allocated into 14 separate groups (n = 6), namely, control, ethanol, 5% glutaraldehyde (GA), 12.5, 25, 50, and 100 mg/ml TF3/ethanol solution groups. Each group was further divided into two subgroups based on crosslinking time: 30 and 60 s. The efficacy and mechanism of TF3’s interaction with dentin type I collagen were predicted through molecular docking. The cross-linking, anti-enzymatic degradation, and biomechanical properties were studied by weight loss, hydroxyproline release, scanning/transmission electron microscopy (SEM/TEM), in situ zymography, surface hardness, thermogravimetric analysis, and swelling ratio. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy were utilized to explore its mechanisms. Statistical analysis was performed using one and two-way analysis of variance and Tukey’s test.Results: TF3/ethanol solution could effectively crosslink demineralized dentin collagen and improve its resistance to collagenase digestion and biomechanical properties (p < 0.05), showing concentration and time dependence. The effect of 25 and 50 mg/ml TF3/ethanol solution was similar to that of 5% GA, whereas the 100 mg/mL TF3/ethanol solution exhibited better performance (p < 0.05). TF3 and dentin type I collagen are mainly cross-linked by hydrogen bonds, and there may be covalent and hydrophobic interactions.Conclusion: TF3 has the capability to efficiently cross-link demineralized dentin collagen, enhancing its resistance to collagenase enzymatic hydrolysis and biomechanical properties within clinically acceptable timeframes (30 s/60 s). Additionally, it exhibits promise in enhancing the longevity of dentin adhesion.
研究领域:
牙科材料
·
胶原化学
·
生物力学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nutrients
·
2021
·Vol. 13
·期 12
·4379
·
IF 5.719
Hui Zhou,Yuanyuan Wu,Eunhye Kim,Haibo Pan,Puming He,Bo Li,Yi Charlie Chen,Youying Tu
Theaflavin-3,3′-digallate (TF3) is the most important theaflavin monomer in black tea. TF3 was proved to reduce blood glucose level in mice and rats. However, the elaborate anti-diabetic mechanism was not well elucidated. In this work, human hepatoma G2 (HepG2) cells and zebrafish (Danio rerio) were used simultaneously to reveal anti-diabetic effect of TF3. The results showed that TF3 could effectively rise glucose absorption capacity in insulin-resistant HepG2 cells and regulate glucose level in diabetic zebrafish. The hypoglycemic effect was mediated through down-regulating phosphoenolpyruvate carboxykinase and up-regulating glucokinase. More importantly, TF3 could significantly improve β cells regeneration in diabetic zebrafish at low concentrations (5 μg/mL and 10 μg/mL), which meant TF3 had a strong anti-diabetic effect. Obviously, this work provided the potential benefit of TF3 on hypoglycemic effect, regulating glucose metabolism enzymes, and protecting β cells. TF3 might be a promising agent for combating diabetes.Keywords:theaflavin-3,3′-digallate;anti-diabetic effect;HepG2 cells;diabetic zebrafish model;glucose metabolism enzymes
研究领域:
生物化学
·
医学
·
药理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TALANTA
·
2024
·
IF 5.6
Guangxuan Chen,Huicong Yuan,Lumei Zhang,Jingran Zhang,Kefeng Li,Xu Wang
The discovery of pancreatic lipase (PL) inhibitors is an essential route to develop new anti-obesity drugs. In this experiment, chitosan was used to add amino groups to cellulose filter paper (CFP) and then glutaraldehyde was used to covalently combine PL with amino-modified CFP through the Schiff base reaction. Under optimal immobilization conditions, CFP immobilized PL has a wide range of pH and temperature tolerance, as well as excellent reproducibility, reusability and storage stability. Subsequently, 26 natural products (NPs) were screened by immobilized PL with black tea extract having the highest inhibition rate. Three compounds with binding effects on PL (epigallocatechin gallate, theaflavin-3-gallate and theaflavin-3,3′-digallate) were captured. Molecular docking proved that these three compounds have a strong binding affinity for PL. Fluorescence spectra further revealed that theaflavin-3,3′-digallate could statically quench the intrinsic fluorescence of pancreatic lipase. The molecular docking and thermodynamic parameters indicated that electrostatic interaction was considered as the main interaction force between PL and theaflavin-3,3′-digallate. Finally, the potential anti-obesity targets and pathways of the three compounds were discussed through network pharmacology. This study not only proposes a simple and efficient method for screening PL inhibitors, but also sheds light on the anti-obesity mechanism of active compounds in black tea.
研究领域:
药理学
·
生物化学
·
分子生物学
·
食品科学
·
生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CELLULAR PHYSIOLOGY
·
2019
·Vol. 234
·期 10
·17999-18016
·
IF 4.522
Zhida Shen,Qi Chen,Tingting Jin,Meihui Wang,Hangying Ying,Jiangting Lu,Ming Wang,Wenbin Zhang,Fuyu Qiu,Chongying Jin,Yanbo Zhao,Guosheng Fu
Theaflavin 3,3′-digallate (TF3), is reported to protect cardiomyocytes from lipotoxicity and reperfusion injury. However, the role of TF3 in the protection of high-glucose injury is still poorly understood. This study investigated the protective effects of TF3 on gap junctions and autophagy in neonatal cardiomyocytes (NRCMs). NRCMs preincubated with high glucose were coincubated with TF3. The expression of connexins and autophagy-related proteins was determined. The functioning of gap-junctional intercellular communication (GJIC) was measured by a dye transfer assay. Adenosine monophosphate-activated protein kinase (AMPK) activity was determined by western blot. Moreover, AMPK was activated with aminoimidazole-4-carboxamide-1-β- d -ribofuranoside (AICAR) or inhibited by AMPKα small interfering RNA (siRNA) to explore the role of AMPK in the modulation of connexin 43 (Cx43) and autophagy. Meanwhile, autophagy was activated or blocked to observe the change in Cx43 expression. It was found that the protein expression of Cx43 and autophagy-related proteins was increased in a TF3 dose- and time-dependent manner under high glucose. TF3 also recovered the reduced GJIC function induced by high glucose concentrations. TF3 activated phosphorylated AMPK in a time-dependent way. AMPKα siRNA abrogated the protection of TF3, while AICAR showed similar results compared to the TF3 treatment. Meanwhile, autophagy activation caused decreased Cx43, while cotreatment with baf A1 enhanced Cx43 expression further compared with the TF3 treatment alone under high glucose. We concluded that TF3 partly reversed the inhibition of Cx43 expression and autophagy induced by high glucose in NRCMs, partly by restoring AMPK activity. Inhibition of autophagy might be protective by preserving Cx43 expression in NRCMs stimulated by high glucose.
研究领域:
心脏病学
·
分子生物学
·
细胞生物学
·
药理学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF FOOD BIOCHEMISTRY
·
2020
·Vol. 45
·期 1
·e13550
·
IF 1.662
Siyuan Li,Lin Yin,Juzhen Yi,Li-Ming Zhang,Liqun Yang
To elucidate the α-glucosidase (α-GC) inhibitory mechanism of theaflavin-3-gallate (TF-3-G), their interaction mechanism was investigated using spectroscopy and molecular docking analysis. The inhibition ratio of TF-3-G against α-GC was determined to be 92.3%. Steady fluorescence spectroscopy showed that TF-3-G effectively quenched the intrinsic fluorescence of α-GC through static quenching, forming a stable complex through hydrophobic interactions. Formation of the TF-3-G/α-GC complex was also confirmed by resonance light scattering spectroscopy. Synchronous fluorescence spectroscopy and circular dichroism spectroscopy indicated that the secondary structure of α-GC was changed by TF-3-G. Molecular docking was used to simulate TF-3-G/α-GC complex formation, showing that TF-3-G might be inserted into the hydrophobic region around the active site of ɑ-GC, and bind with the catalytic Asp215 and Asp352 residues. The ɑ-GC inhibitory mechanism of TF-3-G was mainly attributed to the change in ɑ-GC secondary structure caused by the complex formation. Practical applications α-Glucosidase (α-GC) can hydrolyze the glycosidic bonds of starch and oligosaccharides in food and release glucose. Therefore, the inhibition of α-GC activity has been used to treat postprandial hyperglycemia and type 2 diabetes mellitus. Theaflavin-3-gallate (TF-3-G), a flavonoid found in the fermentation products of black tea, exhibits strong inhibition of α-GC activity. However, the α-GC inhibitory mechanism of TF-3-G is unclear. This study aids understanding of this mechanism, and proposed a possibly basic theory for improving the medicinal value of TF-3-G in diabetes therapy.
研究领域:
生物化学
·
药理学
·
分子生物学
·
糖尿病研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Soft Matter
·
2015
·Vol. 12
·期 4
·1085-1092
·
IF 4.029
Ya-Nan Zhao,Jianjun Gu,Siyu Jia,Ying Guan,Yongjun Zhang
Drug carriers capable of releasing drugs at a constant rate, or following zero-order kinetics, can lead to the best control of plasma drug concentration. Here we demonstrated that zero-order release of polyphenolic drugs, including tannic acid, epigallocatechin gallate, proanthocyanidins, and theaflavin-3′-gallate, could be achieved using hydrogen-bonded layer-by-layer films as the drug carrier. The films were fabricated using the polyphenolic drugs as hydrogen donors and polyethylene glycol (PEG) as the hydrogen acceptor. Because the drugs and PEG are bonded with reversible, dynamic hydrogen bonds, the films disintegrate gradually in aqueous solutions, and thus release the drugs into the media. Furthermore, because the PEG polymers have a narrow molecular weight distribution, the films disintegrate and release the polyphenolic drugs at a constant rate. Besides allowing for zero-order release, the drug carrier developed here also provides various ways to tune the drug release rate. The drug release rate increases with decreasing molecular weight of PEG. More importantly, the release rate could be tuned using external stimuli. Increasing the pH or temperature results in accelerated drug release, while the addition of salt retards the drug release.
研究领域:
药学
·
材料科学
·
药物递送系统
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2021
·
IF 7.514
Jinghui Zhou,Changwei Liu,Shimin Zhao,Ya Liu,Sheng Zhang,Qiang Zhao,Fen Wang,Gang Xu,Jianan Huang,Zhonghua Liu
Theaflavin-3,3ʹ-digallate (TFDG) in black tea possesses several health benefits. However, low TFDG yields limit its application. Herein, tyrosinases from Bacillus megaterium (Bmtyrc) were used to synthesize TFDG. To improve the catalytic efficiency of tyrosinase, a directed evolution strategy and a high-throughput screening method was employed. Compared with the wild type, mutant Bmtyrc-3 (N205D/D166E/D167G/F197W) showed 6.46 and 4.91-folds higher specific activity and 51.97- and 1.95-folds higher Vmax values towards epigallocatechin gallate (EGCG) and epicatechin gallate (ECG), respectively. Moreover, Bmtyrc-3 displayed significantly enhanced catalytic efficiencies, and the space–time yield of TFDG was 35.35 g L -1 d -1 . Bmtyrc-3 presents a broader substrate binding area, caused by a mutation (N205D) encompassing the active site. Changes in the potential of the substrate binding site and hydrogen bonds, and the electrostatic effect on the protein surface resulted in an increased activity of the substrates EGCG and ECG.
研究领域:
生物技术
·
生物化学
·
酶学
·
食品科学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）