Identification of phenolic compounds in aqueous and ethanolic rooibos extracts (Aspalathus linearis) by HPLC-ESI-MS (TOF/IT)

Anal Bioanal Chem. 2011 Jul;400(10):3643-54. doi: 10.1007/s00216-011-4998-z. Epub 2011 Apr 21.

Abstract

Rooibos (Aspalathus linearis) is a rich source of polyphenols and used to make a mild-tasting tea containing no caffeine, is low in tannins compared to green or black teas, and has antioxidant and antimutagenic/antitumoral properties. In vivo results show that rooibos has beneficial effects upon the lipid profile by decreasing serum triglycerides and cholesterol. In this sense, we have developed a simple and rapid method to separate and characterize simultaneously the polyphenolic compounds in aqueous and ethanolic rooibos extracts using high-performance liquid chromatography coupled to electrospray ionization time-of-flight mass spectrometry (HPLC-ESI-TOF-MS) and ion trap multiple mass spectrometry (HPLC-ESI-IT-MS(2)). The phenolic compounds were separated on a C(18) column (4.6 × 150 mm, 1.8 μm) with 1% formic acid in water/acetonitrile 90:10 v/v and acetonitrile as mobile phases. The accuracy mass data generated by TOF-MS together with the fragmentation pattern obtained by IT-MS(2) experiments confirmed the presence of 25 and 30 phenolic compounds in the aqueous and ethanolic extracts, respectively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aspalathus / chemistry*
  • Chromatography, High Pressure Liquid / methods
  • Ethanol
  • Phenols / analysis*
  • Plant Extracts / chemistry*
  • Plant Roots / chemistry
  • Spectrometry, Mass, Electrospray Ionization / methods

Substances

  • Phenols
  • Plant Extracts
  • Ethanol