Guangdong Provincial Key Laboratory of Applied Botany & Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China.
Guangdong Provincial Key Laboratory of Applied Botany & Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China; University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing 100049, China.
Food Chem. 2018 Aug 30;258:352-358. doi: 10.1016/j.foodchem.2018.03.095. Epub 2018 Mar 21.
After tea leaves, tea (Camellia sinensis) flowers are becoming a second tea plant resource because they contain not only functional metabolites similar to those found in tea leaves, but also predominant amounts of functional metabolites that only occur in tea leaves in small amounts. 1-Phenylethanol (1PE) is a predominant aroma compound found in tea flowers. A 1PE synthase in tea flowers was isolated, functionally characterized, and shown to have the highest catalytic efficiency for the conversion of acetophenone (AP). To determine why 1PE accumulates more in tea flowers than other plants, we compared their 1PE contents and used a stable isotope labeling method to elucidate the 1PE biosynthetic route. Supplementation with [H]l-phenylalanine and [H]AP suggested that most plants containing the enzyme/gene catalyzed the conversion of AP to 1PE. Furthermore, the availability of AP derived from l-phenylalanine was responsible for the difference in 1PE accumulation between tea flowers and other plants.
继茶叶之后，茶花正成为第二种茶树资源，因为它们不仅含有与茶叶中发现的功能代谢物相似的功能代谢物，而且还含有大量仅在茶叶中少量存在的功能代谢物。1-苯乙醇（1PE）是茶叶中主要的香气化合物。从茶花中分离出一种 1PE 合酶，对其进行功能表征，并发现其对苯乙酮（AP）的转化具有最高的催化效率。为了确定为什么 1PE 在茶花中的积累量比其他植物多，我们比较了它们的 1PE 含量，并使用稳定同位素标记法阐明了 1PE 的生物合成途径。用[H]l-苯丙氨酸和[H]AP 补充表明，大多数含有该酶/基因的植物催化 AP 转化为 1PE。此外，来源于 l-苯丙氨酸的 AP 的可用性是造成茶花和其他植物之间 1PE 积累差异的原因。
