ANTIOXIDANT PROPERTIES OF MAJOR FLAVONOIDS AND SUBFRACTIONS OF THE EXTRACT OF PHYLLOSTACHYS PUBESCENS LEAVES

Authors


TEL: +86-10-84789868; FAX: +86-10-84713741; EMAIL: yueyd@icbr.ac.cn; gxf71622@icbr.ac.cn

Abstract

ABSTRACT

Six subfractions (H2O eluted fraction, 20% ethanol eluted fraction, 40% ethanol eluted fraction, 60% ethanol eluted fraction, 80% ethanol eluted fraction and acetone fraction) of a 95% ethanol extract of Phyllostachys pubescens leaves were sequentially partitioned by column chromatography (macroporous absorption resin). For the first time, nine specific major flavonoids were isolated from this species. The antioxidant activity levels of these nine major flavonoids and six subfractions were evaluated using a radical-scavenging assay, including 2,2-diphenyl-1-picrylhydrazyl, hydroxyl radicals and superoxide anion radicals. The total flavonoid content of the six subfractions was determined by colorimetry. Results indicated that the nine major flavonoids and three of the subfractions (20, 40,and 60% ethanol) exhibited powerful antioxidant activity. These three subfractions showed high levels of total flavonoid content. Our results suggest that the nine major flavonoids and three subfractions are promising natural alternatives to synthetic antioxidants as functional food ingredients and natural antioxidant.

PRACTICAL APPLICATIONS

Chinese people realized the medical and health-promoting effects of bamboo leaves a long time ago. Bamboo and its extracts are used in traditional Chinese medicine and as food additives. Phyllostachys pubescens is a species of bamboo that is widely cultivated in China, primarily for its shoots. Every year, many bamboo leaves are discarded when the shoots are harvested. In this study, major flavonoids and three subfractions made from P. pubescens leaves showed strong antioxidant activity. This capacity was found to be mainly the result of the extracts' high total flavonoid content. These flavonoids and subfractions could be developed into ingredients for use in foods and as natural antioxidant.

Ancillary