声明
Table of Contents
List of Figures
List of Tables
摘要
ABSTRACT
Chapter 1 Literature of review
1．1 Plant-based products
1．2 Ampelopsis grossedentata
1．3 Isolation and purification of phytochemicals
1．4 Polyphenols as plant metabolites
1．5 Antioxidant activities of plant metabolites
1．6 OBJECTIVES
1．7 TECHNICAL ROUT NIAP OF THE STUDY
Reference
Chapter 2 Isolation and characterization of antimicrobialmetabolite ti-om vine tea with mechanism against Bacillus● ●● 一● -● ● - -’一‘_●cereus(AS 1．1 846)
2．1 Introduction
2．2 Material and methods
2．2．1 Sample preparation
2．2．2 Sephadex LH-20 and Thin-layer chromatography
2．2．3 Isolation of the antibacterial substance by Reverse phase high
2．2．4 Structural identification of vine tea isolates
2．2．5 Antimicrobial activity assay
2．2．6 Statistical analysis
2．3 Results and discussion
2．3．1 Measurement of zone of inhibition(ZOI)，Minimum inhibitory concentration (MICs) and Minimum bacterial concentration (MBC)
2．3．2 Isolation of antibacterial substance by high-performance liquid chromatography (HPLC)
2．3．3 Matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF)
2．3．4 Liquid chromatography tandem mass spectrometry (LC-MS／MS) analysis of isolates
2．3．5 Time kill curve assay
2．3．6 Integrity of cell membrane
2．3．7 Bactericidal kinetics curve
2．3．8 Observation of ultra-cell structural changes in microbial cell wall
2．4 Conclusion
References
Chapter:3 Inhibition and action mode of 5,7,8,3’,4’-Pentahydroxyisoflavone isolated from vine tea,against Staphylococcus aureus ATCC 25923
3．1 Introduction
3．2 Materials and methods
3．2．1 Chemicals，standards and sample preparation
3．2．2 Bacteria cultures
3．2．3 Antimicrobial activity
3．2．4 Antibacterial mechanism
3．2．5 Statistical analysis
3．3 Results and discussion
3．3．1 ZOI,MIC,and MBC of the 5,7,8,3’,4'-pentahydroxyisoflavone
3．3．2 Effect of 5,7,8,3’,4’-pentahydroxyisoflavone on viability of S．aureus ATCC 25923
3．3．3 Effect of 5,7,8,3’,4’-pentahydroxyisoflavone on bacterial cell membrane
3．4 Conclusion
Reference
Chapter 4: Effects of extraction variables on pharmacological activities of Ampelopsis grossedentata
4．1 Introduction
4．2 Materials and methods
4．2．1 Plant material
4．2．2 Chemical reagents
4．2．3 Solvent extraction procedure
4．2．4 Experimental design
4．2．5 Chemical analysis
4．2．6 Validation of the model
4．2．7 Statistical analysis
4．3 Results and discussion
4．3．1 Evaluation of extraction polarity
4．3．2 Evaluation of extraction time
4．3．3 Evaluation of extraction temperature
4．3．4 Pearson correlation analysis
4．1 Conclusion
Reference
Chapter 5: Optimization of dihydromyricetin from Ampelopsis grossedentata, using response surface methodology
5．1 Introduction
5．2 Materials and methods
5．2．1 Plant materials and chemical reagents
5．2．4 Confirmatory analysis of DHM using matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry
5．2．5 Delineating the influence of single factors on DHM extraction／recovery rates and establishing variability ranges
5．2．6 Optimizing DHM extraction parameters through response surface methodology (RSM) and model fitting
5．2．7 Empirical validation of the established model
5．2．8 Statistical analysis
5．3 Results and discussion
5．3．1 Solvent composition／ethanol (％) affected DHM extractability and overall yields
5．3．2 Increasing the temperature of extraction mixtures enhanced DHM yields
5．3．3 Extending extraction times positively influenced DHM overall yields
5．3．4 Using the Box-Behnken Design (BBD) to optimize DHM extractions and testing model compliance with the quadratic fit
5．3．5 The experimental validation of optimal extraction conditions／parameters
5．4 Conclusions
Reference
Chapter 6: Structural identification of two flavonoids and its food preservative etlbct trom vlne tea
6．1 Introduction
6．2 Materials and methods
6．2．1 Preparation of compound A
6．2．2 Preparation of compound B
6．2．3 HPLC-ESI／MS and NMR spectroscopy analysis
6．2．4 NMR spectroscopy
6．2．5 Quantitative analysis
6．2．7 Reducing power assay
6．2．8 In situ antibacterial assay in mutton soup
6．2．9 Sensory evaluation
6．2．10 Statistical analysis
6．3 Results and discussion
6．3．3 HPLC-ESI／MS analysis of compound A
6．3．4 HPLC-ESI／MS analysis of compound B
6．3．5 Identification of an isomer of (-)-dihydromyricetin
6．3．6 DPPH radical-scavenging activity
6．3．7 Reducing power
6．3．8 In situ antibacterial activity in mutton soup
6．3．9 Sensory analysis
6．4 Conclusion
Reference
Main conclusion
NOVELTY OF PRESENT STUDY
Acknowledgement
Publications
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