Abstract:

The purification of polyphenols from the crude aqueous extract of pomegranate peel by macroporous adsorption
resin was investigated by evaluating total polyphenol content, adsorption rate and desorption rate as functions of the
adsorption and desorption conditions. Meanwhile, the contents of punicalagin, ellagic acid, chlorogenic acid, quercetin
and epicatechin were determined by reverse phase high performance liquid chromatography (RP-HPLC). In addition, the
inhibitory effect of purified polyphenols on fatty acid synthase was explored. The results showed that D101 macroporous
resin was the suitable resin for the purification of polyphenols and the purification process involved the following steps:
adjustment of the sample concentration to 10 mg/mL, sample loading at a flow rate of 2 BV/h, column washing with 5 BV
of distilled water, and elution with 5.5 BV of 70% ethanol. The purified product contained 71.64%, significantly higher
than that (49.31%) reported for the crude extract. The contents of punicalagin, ellagic acid, chlorogenic acid, quercetin
and epicatechin in the purified polyphenols were 46.91%, 9.44%, 0.53%, 0.75% and 0.32%, respectively. Moreover, the
polyphenols from pomegranate peel had a potent inhibitory effect on fatty acid synthase with an EC50 (concentration for 50%
of maximal effect) of 0.72 mg/mL.

Key words: pomegranate peel polyphenols, fatty acid synthase, purification, inhibition