Jiao Huijun, Guan Qiuzhu, Dong Ran, Ran Kun, Wang Hongwei, Dong Xiaochang, Wei Shuwei
State Key Laboratory of Nutrient Use and Management, Shandong Institute of Pomology, Longtan Road No. 66, Taian 271000, China.
Plants (Basel). 2024 Sep 7;13(17):2513. doi: 10.3390/plants13172513.
Phenolic compounds are the predominant chemical constituents in the secondary metabolites of plants and are commonly found in pears. In this study, we focused on the analysis of the phenolic composition and antioxidant activity of leaves from five pear cultivars (Cuiguan, Chaohong, Kuerle, Nanguoli, and Yali) and tea leaves (Fudingdabai as the control) using ultra-performance liquid chromatography coupled with electrospray ionization triple quadrupole mass spectrometry. The results indicated significant differences in the amount and composition of phenolic metabolites between tea and pear leaves, as well as among the five pear varieties. Only approximately one-third of the metabolites exhibited higher levels in pear leaves compared to that in tea leaves. The total phenol content in the Yali cultivar was higher than that in the other pear cultivars. Furthermore, specific phenolic metabolites with high expression were identified in the leaves of different groups. The levels of delphinidin 3-glucoside, aesculin, prunin, cosmosiin, quercetin 3-galactoside, isorhamnetin-3-O-glucoside, nicotiflorin, narcissin, chlorogenic acid, and cryptochlorogenic acid were relatively high among the five pear cultivars. (-)-Gallocatechin gallate, 6-methylcoumarin, aesculetin, hesperidin, kaempferol, and caftaric acid were identified as specific metabolic substances unique to each type of pear leaf. Most of the differential metabolites showed positive correlations and were primarily enriched in the flavonoid biosynthesis, flavone and flavonol biosynthesis, and phenylpropanoid biosynthesis pathways. DPPH (1,1-Diphenyl-2-picrylhydrazyl radical) analysis indicated that the Yali cultivar exhibited the highest antioxidant activity compared to other varieties. This systematic analysis of the differences in phenolic metabolite composition and antioxidant activity between pear and tea leaves provides a theoretical foundation for the development and utilization of pear leaf resources.
酚类化合物是植物次生代谢产物中的主要化学成分，常见于梨中。在本研究中，我们采用超高效液相色谱-电喷雾电离三重四极杆质谱联用技术，重点分析了五个梨品种（翠冠、朝红、库尔勒、南果梨和鸭梨）以及茶叶（以福鼎大白茶为对照）叶片中的酚类成分和抗氧化活性。结果表明，茶叶和梨树叶之间以及五个梨品种之间的酚类代谢产物的含量和组成存在显著差异。与茶叶相比，只有约三分之一的代谢产物在梨树叶中含量较高。鸭梨品种的总酚含量高于其他梨品种。此外，在不同组的叶片中鉴定出了高表达的特定酚类代谢产物。在五个梨品种中，飞燕草素3-葡萄糖苷、七叶苷、樱草苷、异鼠李素、槲皮素3-半乳糖苷、异鼠李素-3-O-葡萄糖苷、芦丁、水仙苷、绿原酸和隐绿原酸的含量相对较高。（-）-没食子儿茶素没食子酸酯、6-甲基香豆素、七叶内酯、橙皮苷、山奈酚和咖啡酰奎宁酸被鉴定为每种梨树叶特有的特定代谢物质。大多数差异代谢产物呈正相关，主要富集在黄酮类生物合成、黄酮和黄酮醇生物合成以及苯丙烷类生物合成途径中。DPPH（1,1-二苯基-2-苦基肼自由基）分析表明，与其他品种相比，鸭梨品种的抗氧化活性最高。对梨树叶和茶叶中酚类代谢产物组成和抗氧化活性差异的系统分析为梨树叶资源的开发利用提供了理论依据。
