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

B. Xie, H. Shi, Q. Chen, C. T. Ho

Research output: Contribution to journalArticlepeer-review

117 Scopus citations

Abstract

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.

Original languageEnglish (US)
Pages (from-to)77-84
Number of pages8
JournalProceedings of the National Science Council, Republic of China. Part B, Life sciences
Volume17
Issue number2
StatePublished - Apr 1993

All Science Journal Classification (ASJC) codes

  • Medicine(all)

Fingerprint Dive into the research topics of 'Antioxidant properties of fractions and polyphenol constituents from green, oolong and black teas.'. Together they form a unique fingerprint.

Cite this