茶枝柑与不同品种温州蜜柑果皮的非靶向代谢组学比较与分析

Comparative Untargeted Metabolomics Analysis of the Peels of Citrus reticulata ‘Chachi' and Different Varieties of Citrus unshiu Marc.

分析比较不同品种温州蜜柑与茶枝柑果皮的代谢组学差异,为温州蜜柑果皮的开发利用提供理论基础和科学依据。利用超高效液相色谱-串联质谱对茶枝柑与3个品种温州蜜柑的化学成分进行测定及分析,利用主成分分析、正交偏最小二乘判别分析和聚类分析等多元统计方法对代谢组数据进行比较分析,筛选差异代谢物。通过数据库对比,茶枝柑(CZG)与油良(YL)、南柑20(NG)、宫川(GC)间分别鉴定出790、796、818个代谢物,其中有机氧化合物、黄酮类、羧酸类及其衍生物占比最高,主要参与黄酮和黄酮醇生物合成、黄酮类生物合成、异黄酮生物合成、α-亚麻酸代谢和苯丙氨酯生物合成等代谢途径;根据变量投影重要性值>1且P<0.05,对差异代谢物进行筛选,得到稳定、可靠的差异代谢物,结果表明,茶枝柑与温州蜜柑间共筛选出11类、43种差异代谢物,占比较多的为黄酮类、氨基酸类和嘌呤核苷类化合物,温州蜜柑中黄酮类化合物多为上调,如5,6,7,8,3’,4’,5’-七甲氧基黄酮、槲皮素、柚皮苷、山柰酚和柚皮素等,可作为潜在的标志物区分茶枝柑与温州蜜柑,同时表明温州蜜柑黄酮类化合物含量更具优势,可作为高生物活性的陈皮基原药材,推动柑橘产业发展,为陈皮产品的开发利用及原料选材提供参考依据。

The metabolomic differences between the peels of Citrus reticulata ‘Chachi' and different varieties of Citrus unshiu Marc.were analyzed to provide a theoretical basis and scientific evidence for the development and utilization of the peels of Citrus unshiu Marc..The chemical composition of Citrus reticulata ‘Chachi'(CZG) and three different varieties of Citrus unshiu Marc.(‘Youliang'(YL),‘Nangan 20'(NG) and ‘Gongchuan'(GC)) were determined by ultrahigh performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS),and the metabolomic data were comparatively analyzed using principal component analysis(PCA),orthogonal partial least square-discriminant analysis(OPLS-DA) and cluster analysis(CA) to screen differential metabolites.Through database comparison,790,796 and 818metabolites were identified between CZG and YL,NG and GC,respectively,with organic oxides,flavonoids,carboxylic acids and their derivatives accounting for the highest proportions,which are mainly involved in the metabolic pathways of flavonoid and flavanol biosynthesis,isoflavones biosynthesis,α-linolenic acid metabolism,and phenylpropanoid biosynthesis.Using the cutoff of variable importance in the projection(VIP) score > 1 with P value < 0.05,stable and reliable differential metabolites were selected.A total of 43 differential metabolites of 11 classes were identified between Citrus reticulata ‘Chachi' and Citrus unshiu Marc.,the predominant ones being flavonoids,amino acids and purine nucleosides.Most flavonoids in Citrus unshiu Marc.such as 5,6,7,8,3',4',5'-heptamethoxyflavone,quercetin,naringenin,and naringenin were up-regulated,which could be used as potential markers to differentiate Citrus reticulata ‘Chachi' from Citrus unshiu Marc..Furthermore,Citrus unshiu Marc.had a higher content of flavonoids and therefore could be used as a source of Citri Reticulatae Pericarpium.