Isolation, purification and identification of antioxidants in an aqueous aged garlic extract.
Food Chem. 2015 Nov 15; 187:37-43.FC

Abstract

An aqueous aged garlic extract (AGE) was prepared by soaking sliced garlic in water for 20days at room temperature (23-25 °C). In order to locate the antioxidant ingredients of the aqueous AGE, an activity-guided fractionation approach using ABTS assay, DPPH assay and FRAP assay were conducted to guide the fractionation by means of extraction, column chromatography and semi-preparative HPLC. Some phenols and organosulfur compounds were identified as antioxidants in AGE by GC-MS. Furthermore, UV, IR, ESI-MS, NMR and specific rotation experiments led to the identification of l-phenylalanine, l-tryptophan, (3S)-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid, (1S,3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid, and (1R,3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid as the major antioxidants in the AGE. The EC50 values of these purified tetrahydro-β-carboline derivatives were 0.625-1.334 μmol/mL and 1.063-2.072 μmol/mL in ABTS assay and DPPH assay, respectively. It is the first time for us to identify (3S)-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid as an in vitro antioxidant in AGE.

Links

Publisher Full Text

Authors+Show Affiliations

Wang X
Key Laboratory of Food Nutrition and Safety (Tianjin University of Science & Technology), Ministry of Education, Tianjin 300457, China.
Liu R
Key Laboratory of Food Nutrition and Safety (Tianjin University of Science & Technology), Ministry of Education, Tianjin 300457, China.
Yang Y
Key Laboratory of Food Nutrition and Safety (Tianjin University of Science & Technology), Ministry of Education, Tianjin 300457, China.
Zhang M
Key Laboratory of Food Nutrition and Safety (Tianjin University of Science & Technology), Ministry of Education, Tianjin 300457, China. Electronic address: zm0102@sina.com.

MeSH

AntioxidantsBenzothiazolesCarbolinesChemical FractionationChromatography, High Pressure LiquidGarlicGas Chromatography-Mass SpectrometryMagnetic Resonance SpectroscopyPhenolsPhenylalaninePlant ExtractsSulfonic AcidsTryptophan

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

25976995