Antioxidant properties of fractions and polyphenol constituents from green, oolong and black teas

Proc Natl Sci Counc Repub China B. 1993 Apr;17(2):77-84.


Green, oolong and black teas were extracted with water, and then the water extracts were extracted separately with three types of solvent, chloroform, ethyl acetate and butanol, to obtain eight fractions. Major flavanol was extracted by EtOAc, while most of the alkaloid was in the chloroform fraction. Thearubigin was greatest in the butanol fraction, and most of the amino acid remained in the water fraction. All fractions were systematically analyzed by UV spectrophotometer and reverse phase HPLC for those important components existing in green tea, oolong tea, and black tea. The pure compounds of (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC), (-)-epigallocatechin gallate (EGCG), free theaflavin, theaflavin monogallate-A, theaflavin monogallate-B, and theaflavin digallate were separated by LH-20 chromatography and reverse phase HPLC. All fractions and pure compounds were assayed for antioxidant activity and lipoxygenase inhibition activity. Flavanol showed very strong antioxidant activity and lipoxygenase inhibition.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antioxidants / isolation & purification*
  • Antioxidants / pharmacology
  • Biflavonoids*
  • Catechin / isolation & purification
  • Catechin / pharmacology
  • Chromatography, High Pressure Liquid
  • Flavonoids / isolation & purification*
  • Flavonoids / pharmacology
  • Lipoxygenase Inhibitors / pharmacology
  • Molecular Structure
  • Plant Extracts / isolation & purification*
  • Plant Extracts / pharmacology
  • Tea*


  • Antioxidants
  • Biflavonoids
  • Flavonoids
  • Lipoxygenase Inhibitors
  • Plant Extracts
  • Tea
  • theaflavin
  • Catechin