QUANTIFICATION OF GALLIC ACID AND ELLAGIC ACID FROM THE SEED OF CORNUS OFFICINALIS BY UHPLC METHOD AND THEIR ANTIOXIDANT ACTIVITY

Abstract

Gallic acid and ellagic acid have been identified in the seed of Cornus officinalis by the use of an ultrahigh performance liquid chromatography (UHPLC) method coupled with a diode array detector (DAD). The water extract of C. officinalis seed contained the highest gallic acid content (3.03 ± 0.10 mg/g seed), which was followed by aqueous methanol extract (2.43 ± 0.10 mg/g seed) and aqueous ethanol extract (1.53 ± 0.25 mg/g seed). But a higher concentration (12.32 ± 0.45 mg/g seed) of ellagic acid was obtained from extraction with aqueous methanol than with aqueous ethanol (11.03 ± 0.42 mg/g seed) and water (7.28 ± 0.16 mg/g seed). After heat treatment and acid hydrolysis, C. officinalis seed had higher concentrations of gallic acid and ellagic acid, contributing to more potent antioxidant activity. The results demonstrated a rich source of gallic acid and ellagic acid in C. officinalis seed, which might provide a novel source of these natural antioxidants.

Keywords:

• Antioxidant activity
• Cornus officinalis seed
• Ellagic acid
• Gallic acid
• UHPLC

Acknowledgment

The study was financially supported by the Natural Science Foundation of Jiangsu Province, China (BK2012064).

Notes

Data are expressed as the mean of three determinations ± SD (standard deviation). Different letters in the same column show significant differences from each other at p < 0.05; statistical analysis was done by Duncan's multiple range tests.

^a The antioxidant activity of the extract is expressed as IC₅₀.

^b FRAP values are expressed in mmol ascorbic acid equivalent/g seed.

Data are expressed as the mean of three determinations ± SD. Different letters in the same column show significant differences from each other at p < 0.05; statistical analysis was done by Duncan's multiple range tests.