Kim Heon Woong, Kim Jung Bong, Shanmugavelan Poovan, Kim Se Na, Cho Young Sook, Kim Haeng Ran, Lee Jeong-Tae, Jeon Weon-Tai, Lee Dong Jin
Department of Agro-food Resources, National Academy of Agricultural Science, Rural Development Administration, Suwon 441-883, Republic of Korea.
BMC Res Notes. 2013 Apr 15;6:149. doi: 10.1186/1756-0500-6-149.
Rice is the staple food and one of the world’s three major grain crops. Rice contains more than 100 bioactive substances including phytic acid, isovitexin, γ-oryzanol, phytosterols, octacosanol, squalene, γ-aminobutyric acid (GABA), tocopherol, tocotrienol derivatives, etc. Out of them, γ-oryzanol is known to have important biological profile such as anti-oxidants, inhibitor of cholesterol oxidation, reduce serum cholesterol levels in animals, effective in the treatment of inflammatory diseases, inhibit tumor growth, reduce blood pressure and promotes food storage stability when used as a food additive, etc. Hence in the present investigation, we aimed to evaluate the content and composition of γ-oryzanol from pigmented rice germplasms using a liquid chromatography with diode array detection and electrospray ionization-mass spectrometry (LC-DAD-ESI/MS).
In the present study, 33 exotic pigmented rice accessions (red, white and purple) have been evaluated. Among them, the contents of γ-oryzanol varied from 3.5 to 21.0 mg/100 g with a mean of 11.2 mg/100 g. A total of ten components of γ-oryzanol including Δ⁷-stigmastenyl ferulate were identified of which, cycloartenyl ferulate, 24-methylenecycloartanyl ferulate, campesteryl ferulate and sitosteryl ferulate were identified as the major components. The mean proportions of steryl ferulates were in the descending order of 24-methylenecycloartanyl ferulate > cycloartenyl ferulate > campesteryl ferulate > sitosteryl ferulate > Δ⁷-campestenyl ferulate > campestanyl ferulate > sitostanyl ferulate > Δ⁷-stigmastenyl ferulate > stigamsteryl ferulate > Δ⁷-sitostenyl ferulate. Almost 11 accessions (33%) showed higher content than the control rice Chucheongbyeo and higher proportions ranged from 10 to 15 mg/100 g. Interestingly, the red rice accession Liberian Coll. B11/B-11 (21.0 mg/100 g) showed higher content γ-oryzanol than control rice Jeokjinjubyeo (19.1 mg/100 g) and the purple rice accession Padi Adong Dumarat, Mardi No.4376 (20.3 mg/100 g) showed a similar content with control rice Heugjinjubyeo (21.4 mg/100 g).
Most of analyzed rice accessions were found to possess higher contents of γ-oryzanol than the control rice, Chucheongbyeo. In particular, the red accessions showed highest content than the white and purpleaccessions. The content and composition of γ-oryzanol in 33 exotic pigmented rice accessions have been evaluated and compared significantly by the present investigation.
水稻是主食之一，也是世界三大主要粮食作物之一。水稻含有100多种生物活性物质，包括植酸、异荭草素、γ-谷维素、植物甾醇、二十八烷醇、角鲨烯、γ-氨基丁酸（GABA）、生育酚、生育三烯酚衍生物等。其中，γ-谷维素具有重要的生物学特性，如抗氧化剂、胆固醇氧化抑制剂、降低动物血清胆固醇水平、有效治疗炎症性疾病、抑制肿瘤生长、降低血压以及用作食品添加剂时可促进食品储存稳定性等。因此，在本研究中，我们旨在使用二极管阵列检测和电喷雾电离质谱联用的液相色谱法（LC-DAD-ESI/MS）评估有色水稻种质中γ-谷维素的含量和组成。
在本研究中，对33份外来有色水稻种质（红色、白色和紫色）进行了评估。其中，γ-谷维素的含量在3.5至21.0毫克/100克之间，平均为11.2毫克/100克。共鉴定出十种γ-谷维素成分，包括Δ⁷-豆甾烯基阿魏酸酯，其中阿魏酸环阿屯酯、阿魏酸24-亚甲基环阿屯酯、阿魏酸菜油甾酯和阿魏酸谷甾酯被鉴定为主要成分。甾醇阿魏酸酯的平均比例从高到低依次为：阿魏酸24-亚甲基环阿屯酯＞阿魏酸环阿屯酯＞阿魏酸菜油甾酯＞阿魏酸谷甾酯＞Δ⁷-菜油甾烯基阿魏酸酯＞阿魏酸菜子甾酯＞阿魏酸谷甾烷酯＞Δ⁷-豆甾烯基阿魏酸酯＞阿魏酸豆甾酯＞Δ⁷-谷甾烯基阿魏酸酯。几乎有11份种质（33%）的γ-谷维素含量高于对照水稻“秋光”，较高比例在10至15毫克/100克之间。有趣的是，红米种质利比里亚Coll. B11/B-11（21.0毫克/100克）的γ-谷维素含量高于对照水稻“竹锦朱”（19.1毫克/100克）；紫米种质“Padi Adong Dumarat，Mardi No.4376”（20.3毫克/100克）的含量与对照水稻“黑锦朱”（21.4毫克/100克）相似。
大多数分析的水稻种质的γ-谷维素含量高于对照水稻“秋光”。特别是，红色种质的含量高于白色和紫色种质。本研究对33份外来有色水稻种质中γ-谷维素的含量和组成进行了评估并进行了显著比较。
