Harbaum Britta, Hubbermann Eva Maria, Wolff Christian, Herges Rainer, Zhu Zhujun, Schwarz Karin
Department of Food Technology, Institute of Human Nutrition and Food Science, University of Kiel, Heinrich-Hecht-Platz 10, 24118 Kiel, Germany.
J Agric Food Chem. 2007 Oct 3;55(20):8251-60. doi: 10.1021/jf071314+. Epub 2007 Sep 12.
Twenty-eight polyphenols (11 flavonoid derivatives and 17 hydroxycinnamic acid derivatives) were detected in different cultivars of the Chinese cabbage pak choi ( Brassica campestris L. ssp. chinensis var. communis) by HPLC-DAD-ESI-MS(n). Kaempferol was found to be the major flavonoid in pak choi, glycosylated and acylated with different compounds. Smaller amounts of isorhamnetin were also detected. A structural determination was carried out by (1)H and (13)C NMR spectroscopy for the main compound, kaempferol-3-O-hydroxyferuloylsophoroside-7-O-glucoside, for the first time. Hydroxycinnamic acid derivatives were identified as different esters of quinic acid, glycosides, and malic acid. The latter ones are described for the first time in cabbages. The content of polyphenols was determined in 11 cultivars of pak choi, with higher concentrations present in the leaf blade than in the leaf stem. Hydroxycinnamic acid esters, particularly malic acid derivatives, are present in both the leaf blade and leaf stem, whereas flavonoid levels were determined only in the leaf blade.
采用高效液相色谱-二极管阵列检测器-电喷雾串联质谱（HPLC-DAD-ESI-MS(n)）对不同品种的小白菜（Brassica campestris L. ssp. chinensis var. communis）中的28种多酚（11种黄酮类衍生物和17种羟基肉桂酸衍生物）进行了检测。发现山奈酚是小白菜中的主要黄酮类化合物，它与不同的化合物发生了糖基化和酰化反应。还检测到了少量的异鼠李素。首次通过氢核磁共振（¹H）和碳核磁共振（¹³C）光谱对主要化合物山奈酚-3-O-羟基阿魏酰槐糖甙-7-O-葡萄糖甙进行了结构测定。羟基肉桂酸衍生物被鉴定为奎宁酸、糖苷和苹果酸的不同酯类。后者在白菜中是首次被描述。测定了11个小白菜品种中的多酚含量，叶片中的浓度高于叶茎。羟基肉桂酸酯，特别是苹果酸衍生物，在叶片和叶茎中均有存在，而黄酮类化合物的含量仅在叶片中测定。
