Whitaker Bruce D, Stommel John R
Produce Quality and Safety Laboratory and Vegetable Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, USDA, 10300 Baltimore Avenue, Beltsville, Maryland 20705-2350, USA.
J Agric Food Chem. 2003 May 21;51(11):3448-54. doi: 10.1021/jf026250b.
There is gathering evidence that antioxidant phytonutrients in fruits and vegetables have health-promoting effects. Eggplant fruit have a high content of antioxidant phenolic compounds. We evaluated the main class of eggplant phenolics, hydroxycinnamic acid conjugates, in the fruit of seven commercial cultivars. Fourteen conjugates were quantified and identified by high-performance liquid chromatography, ES(-)-MS, and (1)H NMR data. Significant differences in their content and composition were evident among cultivars and in tissue from stem, middle, and blossom end segments. Chlorogenic acid (5-O-caffeoylquinic acid) was the predominant compound, and its 3-O-, 4-O-, and 5-O-cis isomers were also present. The 10 other phenolics fell into four groups, including 3,5- and 4,5-dicaffeoylquinic acid isomers, four amide conjugates, two unknown caffeic acid conjugates, and 3-O-acetyl esters of 5-O- and 4-O-caffeoylquinic acid. Dicaffeoylquinic and 3-O-acetyl chlorogenic acids were most variable among the cultivars. Dicaffeoyquinic acids were most abundant in the blossom end, whereas 3-O-acetyl esters were highest in the midsection.
越来越多的证据表明，水果和蔬菜中的抗氧化植物营养素具有促进健康的作用。茄子果实中含有大量抗氧化酚类化合物。我们评估了七个商业品种茄子果实中主要的酚类物质——羟基肉桂酸共轭物。通过高效液相色谱、电喷雾负离子质谱（ES(-)-MS）和核磁共振氢谱（(1)H NMR）数据对14种共轭物进行了定量和鉴定。不同品种以及茄子茎部、中部和花萼端组织中的共轭物含量和组成存在显著差异。绿原酸（5-O-咖啡酰奎尼酸）是主要成分，其3-O-、4-O-和5-O-顺式异构体也有存在。其他10种酚类物质分为四组，包括3,5-和4,5-二咖啡酰奎尼酸异构体、四种酰胺共轭物、两种未知的咖啡酸共轭物以及5-O-和4-O-咖啡酰奎尼酸的3-O-乙酰酯。二咖啡酰奎尼酸和3-O-乙酰基绿原酸在不同品种间变化最大。二咖啡酰奎尼酸在花萼端含量最高，而3-O-乙酰酯在中部含量最高。
