PUBLICATION

Structural Characteristics and Hypolipidemic Activity of Theabrownins from Dark Tea Fermented by Single Species Eurotium cristatum PW-1

Authors
Xiao, Y., Li, M., Wu, Y., Zhong, K., Gao, H.
ID
ZDB-PUB-200207-17
Date
2020
Source
Biomolecules   10(2): (Journal)
Registered Authors
Keywords
E. cristatum fermented loose tea, fractionated, hypolipidemic activity, structural characteristics, theabrownins
MeSH Terms
  • Animals
  • Aspergillus/metabolism*
  • Catechin/analogs & derivatives*
  • Catechin/chemistry
  • Catechin/pharmacology
  • Disease Models, Animal
  • Fermentation*
  • Gas Chromatography-Mass Spectrometry
  • Hyperlipidemias/drug therapy*
  • Molecular Weight
  • Obesity/drug therapy*
  • Phenol/chemistry
  • Plant Extracts/chemistry*
  • Spectrophotometry, Ultraviolet
  • Spectroscopy, Fourier Transform Infrared
  • Tea/chemistry*
  • X-Ray Diffraction
  • Zebrafish
PubMed
32019226 Full text @ Biomolecules
Abstract
Recently, studies on theabrownins (TBs), the main bioactive polymeric pigments found in dark tea, have received increasing attention for its health effects. Thus far, information on their structural characteristics is unclear. In the present study, theabrownins were isolated from single species Eurotium cristatum PW-1-fermented loose tea and their structural and hypolipidemic characteristics were studied for the first time. The theabrownins were fractionated by their molecular weights and were then analyzed. Ultraviolet-visible spectrophotometry (UV-Vis) and Flourier transformation infrared spectroscopy (FT-IR) showed that they were polymerized phenolic substances containing abundant hydroxy and carboxyl groups. All theabrownin samples exhibited hypolipidemic activity in high-fat zebrafish; among which TBs-10-30k sample, decreased lipid level in high-fat zebrafish to 51.57% at 1000 μg/mL, was most effective. It was found that TBs-10-30k was a type of amorphous and thermostable polymer with slice shape and smooth surface under scanning electron microscope (SEM). Atomic force microscope (AFM) analysis showed that it had island-like structure because of aggregation of theabrownin molecules. Pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) analysis further showed that the main pyrolytic products of TBs-10-30k were hexadecanoic acid (33.72%), phenol (14.90%), and eicosane (12.95%), indicating TBs-10-30k was mainly composed of phenols, lipids, saccharides, and proteins. These results not only facilitate subsequent identification of theabrownins, but also provide insights into the applications of theabrownins in functional foods.
Genes / Markers
Figures
Show all Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping