Isolation, identification and antioxidant activity of bound phenolic compounds present in rice bran

  • Food Chem. 2015 Mar 15;171:40-9. doi: 10.1016/j.foodchem.2014.08.095.
Wei Wang  1 ,  Jia Guo  1 ,  Junnan Zhang  1 ,  Jie Peng  1 ,  Tianxing Liu  1 ,  Zhihong Xin  2
Affiliations
  • 1. Key Laboratory of Food Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China.
  • 2. Key Laboratory of Food Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China. Electronic address: [email protected].
PMID: 25308640 DOI: 10.1016/j.foodchem.2014.08.095
Abstract

The bound phenolic compounds in rice bran were released and extracted with ethyl acetate based on alkaline digestion. An investigation of the chemical constituents of EtOAc extract has led to the isolation of a new compound, para-hydroxy methyl benzoate glucoside (8), together with nine known compounds, cycloeucalenol cis-ferulate (1), cycloeucalenol trans-ferulate (2), trans-ferulic acid (3), trans-ferulic acid methyl ester (4), cis-ferulic acid (5), cis-ferulic acid methyl ester (6), methyl caffeate (7), vanillic aldehyde (9) and para-hydroxy benzaldehyde (10). The structures of these compounds were determined using a combination of spectroscopic methods and chemical analysis. Among the compounds isolated, compound 3, 5 and 7 exhibited strong DPPH and ABTS(+) radical scavenging activities, followed by compounds 4 and 6. Compound 1 and 2 showed potent DPPH and ABTS(+) radical scavenging activities, compound 8 displayed moderate antioxidant activity against ABTS(+) radical, whereas compound 9 and 10 showed weak antioxidant activity.

Keywords
Alkaline hydrolysis; Antioxidant activities; Bound phenolic compounds; Rice bran; Structural identification.
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