Partial Purification, Identification, and Quantitation of Antioxidants from Wild Rice (Zizania latifolia).

Mei-Jun Chu,Xin-Min Liu,Zhong-Feng Zhang,Ning Yan,Feng-Zhong Wang,Yong-Mei Du

doi:10.3390/molecules23112782

Mei-Jun Chu, Xin-Min Liu + Show 4 more

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https://doi.org/10.3390/molecules23112782

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Abstract

To provide further insights into the potential health-promoting antioxidants from wild rice (Zizania latifolia), which is an abundant but underutilized whole grain resource in East Asia, a partial purification based on D101 macroporous resin was carried out for the purification and enrichment of the antioxidants from the bioactive ethanol extracts of wild rice. On that basis, 34 phenolic compounds in the antioxidant fractions were identified by a high-performance liquid chromatography-linear ion trap quadrupole-Orbitrap-mass spectrometry (HPLC-LTQ-Orbitrap-MSn). The results suggested that phenolic acids could be enriched in the 10% ethanol-eluted fraction whereas flavonoids (including procyanidins and flavonoid glycosides) could be enriched in 20–30% ethanol-eluted fractions. A quantitative analysis determined by the multiple reaction monitoring mode of the ultra-performance liquid chromatography-triple quadrupole-tandem mass spectrometry (UPLC-QqQ-MS/MS) revealed a high content of procyanidins in wild rice. Compared with phenolic acids, flavonoids may contribute more to the potent antioxidant activity of wild rice. This is the first study on the antioxidants from wild rice Z. latifolia. These findings provide novel information on the functional components of wild rice, and will be of value to further research and development on Z. latifolia.

Highlights

Wild rice is the seed of an aquatic plant belonging to the genus Zizania, family Poaceae
Considering the significant effect of the extraction solvent on the antioxidants extracted from plants [19,20,21], twelve different types of solvents were used to select the suitable solvent to get the maximum extraction of antioxidants from wild rice, since they were the most common ones for the extraction of antioxidants from plants [7,13,19,22]
All the statistical analyses were performed using SPSS 19.0 for Windows (SPSS Inc., Chicago, IL, USA). During this first investigation on the antioxidants from wild rice Z. latifolia, the ethanol extract of this species was demonstrated to be a potent source of natural antioxidants, that can be enriched in

Summary

Introduction

Wild rice is the seed of an aquatic plant belonging to the genus Zizania, family Poaceae. North America, whereas Z. latifolia is native to East Asia [1]. Wild rice is an age-old grain that has been used to treat diabetes and other diseases associated with nutrition, in Chinese medicinal practice, with a recorded history of over three thousand years of use in China. Today its use as a grain has almost disappeared, owing to the very different ripening times and easy seed shattering of the cereal [3,4,5]. In North America, dehulled but unpolished wild rice was historically consumed by Native Americans as a staple food [6]. North American wild rice has been widely used in gourmet food products because of its unique flavor, color, and texture [7]

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