基于UPLC-MS/MS的油茶种仁成分差异分析及其油脂抗氧化活性研究

Differential Composition Analysis of Seed Kernels between Two Camellia Species by UPLC-MS/MS and the Antioxidant Activity Research of Seed Kernels Oil

为研究油茶种仁的主要代谢成分,分析高州油茶和普通油茶内种仁成分差异,比较2种油茶种仁油脂的抗氧化活性。采用超高效液相色谱-串联质谱广泛靶向代谢组技术,通过聚类分析、样本相关性分析和正交偏最小二乘判别分析等方法,比较相同生境下高州油茶和普通油茶内种仁的代谢物质成分的异同,最后以索氏提取法提取种仁油脂,比较油脂抗氧化活性差异。结果表明:从2种油茶种仁中共检出11类536种代谢物,其中高州油茶种仁特有代谢物25种,普通油茶种仁特有代谢物16种。2种油茶种仁筛选得到差异代谢物197种,占总代谢物的36.75%,其中高州油茶种仁相对普通油茶种仁有103种代谢物含量较高,占总差异代谢物52.28%,94种成分含量较低,占总差异代谢物47.72%;197种差异代谢物主要分布在20条代谢途径中,前4条通路分别是黄酮生物合成通路、苯丙烷生物合成通路、酪氨酸代谢通路和花青素生物合成通路。两种油茶种仁油脂的抗氧化活性:高州油茶茶籽油的DPPH自由基清除率在油脂质量浓度大于6.0 mg/mL时略高于普通油茶,且当油脂质量浓度超过0.4 mg/mL时,高州油茶茶油的羟基清除率略高于普通油茶。高州油茶种仁含有丰富的黄酮类和酚酸类化合物,且脂质的种类与含量比普通油茶种仁丰富。油茶种仁的代谢物差异可能是影响两种茶油成分、抗氧化活性不同的关键因素。

In order to study the metabolic components of Camellia oleifera kernels,and metabolites difference in seed kernel in Camellia drupifera and Camellia oleifera were explored at the same time,then antioxidant activity of kernels oils in Camellia drupifera and Camellia oleifera were detected.Broadly targeted metabolomics based on ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)was used to detect differential metabolites between Camellia drupifera and Camellia oleifera.The metabolites in the kernels of two Camellia species were compared via cluster analysis,correlation analysis and orthogonal partial least squares discriminant analysis(OPLS-DA).Finally,the seed kernel oil was extracted by Soxhlet extraction method,and the difference in antioxidant activity of the oil was compared.The results showed that 25 metabolites Camellia drupifera owned and 16 metabolites Camellia oleifera owned were filtered in the 536 metabolites belonging to 11 classes detected in the kernels of two Camellia species.197 differential metabolites were filtered among the whole 536 metabolites,and made up 36.75%.Amond them,103 metabolites were expressed higher in Camellia drupifera than Camellia oleifera,which made up 52.28% in total differentially expressed metabolites;94 metabolites were expressed in lower levels than Camellia oleifera,which made up 47.72% of 197 differential metabolites;These 197 metabolites differentially expressed in two Camellia species mainly participated in 20 pathways,flavonoid biosynthesis,phenylpropanoid biosynthesis,tyrosine metabolism and anthocyanin biosynthesis were the pathways occupying top 4 differential metabolites,and there were 7 metabolites(3.55%),5 metabolites(2.54%),4 metabolites(2.03%)and 4 metabolites(2.03%),respectively.The variety and content of flavonoids and lipids in Camellia drupifera were more abundant than Camellia oleifera.The antioxidant activity tests showed that the DPPH free radical scavenging rate of Camellia drupifera seed oil was slightly higher than that of Camellia oleifera when the oil mass concentration was greater than 6.0 mg/m L,and when the oil mass concentration exceeded 0.4 mg/m L,the hydroxyl clearance rate of Camellia drupifera was slightly higher than that of Camellia oleifera.The seed kernels of Camellia drupifera were rich in flavonoids and phenolic acid compounds,and the types and content of lipids are more abundant than those in Camellia oleifera seed kernels.The difference expression metabolites of seed kernels may be the key factor affecting the composition and antioxidant activity of the two types of Camellia oil.