茶叶中降血糖成分的研究
发布时间：2023-10-28 15:54
近年来,天然产物在营养、保健、化妆品、饲料和药品等领域受到越来越多的关注。茶叶是世界上消费量第二大的饮料,它在亚洲的应用历史悠久,特别是在中国和日本。根据不同的发酵程度,茶叶主要分为三大类:绿茶(未发酵)、乌龙茶(半发酵)和红茶(全发酵)。茶叶的化学成分非常复杂,包括(1)碳水化合物:如多糖、纤维素、果胶、葡萄糖、果糖;(2)多酚:包括儿茶素、花色苷、黄酮类等;(3)蛋白质;(4)氨基酸:如茶氨酸、色氨酸、甘氨酸;(5)维生素(B,C,E);(6)生物碱类:如咖啡因和茶碱;还有脂肪类、挥发性成分、矿物质和微量元素等。其中,茶叶中的活性成分主要是茶多糖(TPS)和茶多酚,这两者是茶叶发挥抗氧化、抗癌、免疫调节和抗糖尿病等药用价值的两个重要成分,其中表没食子儿茶素没食子酸酯(EGCG)是茶多酚的主要组成成分。食物和口服药在人体内的消化起始于口腔的咀嚼和唾液酶的作用,然后进入到胃肠,消化道环境的温度、pH值、胃蛋白酶、胰酶和其他消化酶、肠道菌群等能够影响物质在体内的消化和吸收,这些因素可能改变物质的理化性质、稳定性、生物利用度和生物活性等。多糖的分子量、化学成分、结构和构象的变化能够影响其生...
【文章页数】：86 页
【学位级别】：硕士
【文章目录】：
摘要
abstract
Chapter 1 General introduction
1.1 An overview of tea
1.1.1 Chemical components of tea
1.1.2 Tea polysaccharides
1.1.3 Tea polyphenols
1.2 Research progress on digestion and fermentation of polysaccharides
1.3 Antidiabetic mechanisms related to T2DM
1.3.1 α-amylase and α-glucosidase inhibitory effects
1.3.2 Targeting β cell dysfunction
1.3.3 Targeting signal pathways
1.3.4 Modulation of gut microbiota
1.4 Research progress on protein-polyphenols-polysaccharides interaction in drugdelivery system
1.4.1 Interaction between protein and polyphenols
1.4.2 Interaction between protein and polysaccharides
1.4.3 Interaction between polyphenols and polysaccharides
1.4.4 Protein-polyphenols-polysaccharides nanoparticles
1.5 Significance of the study
Chapter 2 In vitro simulated digestion of tea polysaccharides
2.1 Introduction
2.2 General experimental procedures
2.3 Methods
2.3.1 TPS preparation
2.3.2 Simulated digestion in vitro
2.3.3 UV-vis spectrophotometric measurement of TPS
2.3.4 IR fingerprint experiment of TPS
2.3.5 Morphological properties of TPS
2.3.6 Determination of molecular weight distribution of TPS
2.3.7 Determination of reducing sugar
2.3.8 Determination of monosaccharide changes of TPS
2.3.9 α-amylase inhibitory effects of TPS
2.3.10 Statistical analysis
2.4 Results and Discussion
2.4.1 UV-vis spectra fingerprint of TPS before and after simulated digestion in vitro
2.4.2 IR spectra of TPS before and after simulated digestion in vitro
2.4.3 Morphological properties of TPS before and after simulated digestion in vitro
2.4.4 Molecular weight changes of TPS after simulated digestion in vitro
2.4.5 Changes of the contents of reducing sugar
2.4.6 Monosaccharide composition changes of TPS after gastric and intestinaldigestion
2.4.7 α-amylase inhibitory effects of TPS before and after the simulated digestion
2.5 Conclusion
Chapter 3 Interaction of EGCG with α-glucosidase and in vitro evaluation ofantidiabetic activity
3.1 Introduction
3.2 General experimental procedures
3.3 Methods
3.3.1 Inhibitory effects of EGCG on α-glucosidase
3.3.2 Fluorescence spectroscopy analysis
3.3.3 FI-IR spectra analysis
3.3.4 Molecular docking analysis
3.3.5 Cell culture
3.3.6 Cell viability
3.3.7 Glucose uptake
3.3.8 Oil red o staining
3.3.9 Statistical analysis
3.4 Results and discussion
3.4.1 α-Glucosidase inhibition studies
3.4.2 Fluorescence quenching of α-glucosidase by EGCG
3.4.3 FT-IR measurements
3.4.4 Molecular docking analysis
3.4.5 Glucose uptake
3.4.6 Oil red o staining
3.5 Conclusion
Chapter 4 Encapsulation of EGCG in BSA/Tea Polysaccharides nanoparticles
4.1 Introduction
4.2 General experimental procedures
4.3 Methods
4.3.1 TPS-2 (30-80 KDa) preparation
4.3.2 Nanoparticle preparation
4.3.3 Characterization of nanoparticles
4.3.4 In vitro release of EGCG from nanoparticles
4.3.5 Antioxidant activities
4.3.6 Statistical analysis
4.4 Results and discussion
4.4.1 Loading efficiency and loading capacity
4.4.2 Characterization of nanoparticles
4.4.3 In vitro release of EGCG from nanoparticles
4.4.4 Antioxidant activities
4.5 Conclusion
Chapter 5 Conclusions and prospect
References
Appendix
Publications and participation in scientific research
Acknowledgement
本文编号：3857306
【文章页数】：86 页
【学位级别】：硕士
【文章目录】：
摘要
abstract
Chapter 1 General introduction
1.1 An overview of tea
1.1.1 Chemical components of tea
1.1.2 Tea polysaccharides
1.1.3 Tea polyphenols
1.2 Research progress on digestion and fermentation of polysaccharides
1.3 Antidiabetic mechanisms related to T2DM
1.3.1 α-amylase and α-glucosidase inhibitory effects
1.3.2 Targeting β cell dysfunction
1.3.3 Targeting signal pathways
1.3.4 Modulation of gut microbiota
1.4 Research progress on protein-polyphenols-polysaccharides interaction in drugdelivery system
1.4.1 Interaction between protein and polyphenols
1.4.2 Interaction between protein and polysaccharides
1.4.3 Interaction between polyphenols and polysaccharides
1.4.4 Protein-polyphenols-polysaccharides nanoparticles
1.5 Significance of the study
Chapter 2 In vitro simulated digestion of tea polysaccharides
2.1 Introduction
2.2 General experimental procedures
2.3 Methods
2.3.1 TPS preparation
2.3.2 Simulated digestion in vitro
2.3.3 UV-vis spectrophotometric measurement of TPS
2.3.4 IR fingerprint experiment of TPS
2.3.5 Morphological properties of TPS
2.3.6 Determination of molecular weight distribution of TPS
2.3.7 Determination of reducing sugar
2.3.8 Determination of monosaccharide changes of TPS
2.3.9 α-amylase inhibitory effects of TPS
2.3.10 Statistical analysis
2.4 Results and Discussion
2.4.1 UV-vis spectra fingerprint of TPS before and after simulated digestion in vitro
2.4.2 IR spectra of TPS before and after simulated digestion in vitro
2.4.3 Morphological properties of TPS before and after simulated digestion in vitro
2.4.4 Molecular weight changes of TPS after simulated digestion in vitro
2.4.5 Changes of the contents of reducing sugar
2.4.6 Monosaccharide composition changes of TPS after gastric and intestinaldigestion
2.4.7 α-amylase inhibitory effects of TPS before and after the simulated digestion
2.5 Conclusion
Chapter 3 Interaction of EGCG with α-glucosidase and in vitro evaluation ofantidiabetic activity
3.1 Introduction
3.2 General experimental procedures
3.3 Methods
3.3.1 Inhibitory effects of EGCG on α-glucosidase
3.3.2 Fluorescence spectroscopy analysis
3.3.3 FI-IR spectra analysis
3.3.4 Molecular docking analysis
3.3.5 Cell culture
3.3.6 Cell viability
3.3.7 Glucose uptake
3.3.8 Oil red o staining
3.3.9 Statistical analysis
3.4 Results and discussion
3.4.1 α-Glucosidase inhibition studies
3.4.2 Fluorescence quenching of α-glucosidase by EGCG
3.4.3 FT-IR measurements
3.4.4 Molecular docking analysis
3.4.5 Glucose uptake
3.4.6 Oil red o staining
3.5 Conclusion
Chapter 4 Encapsulation of EGCG in BSA/Tea Polysaccharides nanoparticles
4.1 Introduction
4.2 General experimental procedures
4.3 Methods
4.3.1 TPS-2 (30-80 KDa) preparation
4.3.2 Nanoparticle preparation
4.3.3 Characterization of nanoparticles
4.3.4 In vitro release of EGCG from nanoparticles
4.3.5 Antioxidant activities
4.3.6 Statistical analysis
4.4 Results and discussion
4.4.1 Loading efficiency and loading capacity
4.4.2 Characterization of nanoparticles
4.4.3 In vitro release of EGCG from nanoparticles
4.4.4 Antioxidant activities
4.5 Conclusion
Chapter 5 Conclusions and prospect
References
Appendix
Publications and participation in scientific research
Acknowledgement
本文编号：3857306
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