Wang Wei, Guo Jia, Zhang Junnan, Peng Jie, Liu Tianxing, Xin Zhihong
Key Laboratory of Food Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China.
Key Laboratory of Food Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China.
Food Chem. 2015 Mar 15;171:40-9. doi: 10.1016/j.foodchem.2014.08.095. Epub 2014 Aug 29.
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.
基于碱性消化，米糠中的结合酚类化合物得以释放并用乙酸乙酯萃取。对乙酸乙酯提取物化学成分的研究导致分离出一种新化合物对羟基甲基苯甲酸葡萄糖苷（8），以及九种已知化合物，环桉醇顺式阿魏酸酯（1）、环桉醇反式阿魏酸酯（2）、反式阿魏酸（3）、反式阿魏酸甲酯（4）、顺式阿魏酸（5）、顺式阿魏酸甲酯（6）、咖啡酸甲酯（7）、香草醛（9）和对羟基苯甲醛（10）。这些化合物的结构通过光谱方法和化学分析相结合的方式确定。在分离出的化合物中，化合物3、5和7表现出较强的DPPH和ABTS(+)自由基清除活性，其次是化合物4和6。化合物1和2表现出较强的DPPH和ABTS(+)自由基清除活性，化合物8对ABTS(+)自由基表现出中等抗氧化活性，而化合物9和10表现出较弱的抗氧化活性。
