贵州两地野生大厂茶嘌呤生物碱与儿茶素组分比较

Comparison of purine alkaloids and catechin components of wild Camellia tachangensis in Pu an County and Panzhou County,Guizhou Province,China

探明普安和盘州两地野生大厂茶生化差异,为贵州野生大厂茶资源的保护与开发利用提供科学依据,以普安和盘州两地40份野生大厂茶为材料,采用高效液相色谱法(HPLC)测定大厂茶春季一芽二叶新梢的嘌呤生物碱组分和儿茶素组分和含量,并结合聚类分析和正交偏最小二乘判别分析(OPLS-DA),对两地大厂茶种质资源进行类别区分和关键差异化合物筛选。结果表明,两地大厂茶种质资源中主要嘌呤生物碱不同,普安大厂茶为咖啡碱,盘州大厂茶为苦茶碱。表儿茶素没食子酸酯(epigallocatechin gallate,ECG)和表儿茶素(epicatechin,EC)是大厂茶中含量较突出的儿茶素组分。两地大厂茶的苦茶碱、咖啡碱、没食子酸、儿茶素(catechin,C)和表儿茶素(epicatechin,EC)含量存在极显著差异,普安大厂茶中咖啡碱和没食子酸含量平均值分别为28.53 mg·g^(-1)和0.29 mg·g^(-1),极显著高于盘州大厂茶(2.92 mg·g^(-1)和0.13 mg·g^(-1))。盘州大厂茶中苦茶碱、C和EC含量平均值分别是22.88、2.37、36.83 mg·g^(-1),极显著高于普安大厂茶(1.58、1.81、26.55 mg·g^(-1))。相关性分析显示,11个生化成分间相关性较强,有14对呈显著或极显著正相关,16对呈显著或极显著负相关。聚类分析结果显示:40份野生大厂茶可分为3类,第Ⅰ类为30份盘州大厂茶种质资源,主要生化特点是苦茶碱和C含量较高,咖啡碱含量较低;10份普安大厂茶资源被分作两类,GT-PA-03等7份种质资源构成第Ⅱ类,它们的咖啡碱、EC和ECG含量较高,苦茶碱、没食子酸、表没食子儿茶素(epigallocatechin,EGC)、C、表没食子儿茶素没食子酸酯(epigallocatechin gallate,EGCG)含量较低;GT-PA-01、GT-PA-02和GT-PA-09组成第Ⅲ类,它们的没食子酸、EGC和EGCG含量较高。OPLS-DA分析结果显示,咖啡碱、苦茶碱和没食子酸是区分普安和盘州两地大厂茶的关键生化因子。40份大厂茶种质资源中筛选出高苦茶碱(>25.0 mg·g^(-1))种质3份,高没食子儿茶素没食子酸酯(gallocatechin gallate,GCG)(>15.0 mg·g^(-1))种质2份,高ECG(>80.0 mg·g^(-1))种质3份,高EC(>50.0 mg·g^(-1))种质3份。

The objective of this study was not only to explore the biochemical differences between wild Camellia tachangensis in Pu an County and Panzhou County,but also to provide the scientific basis for the protection,development and utilization of wild C.tachangensis in Guizhou.A total of 40 C.tachangensis germplasm resources from Pu an County and Panzhou County were used as materials,the contents of theobromine,theophylline,theacrine,caffeine,gallic acid,epigallocatechin(EGC),catechin(C),epicatechin(EC),epigallocatechin gallate(EGCG),gallocatechin gallate(GCG)and epigallocatechin gallate(ECG)were determined by high performance liquid chromatography(HPLC).Cluster analysis and orthogonal partial least squares discriminant analysis(OPLS-DA)were used to classify C.tachangensis germplasm resources from two regions and select key differential compounds.The results showed that the main purine alkaloids in C.tachangensis from Pu an and Panzhou were caffeine and theacrine,respectively.ECG and EC were the prominent components of catechin in C.tachangensis.The contents of theacrine,caffeine,gallic acid,C and EC in C.tachangensis from two regions were significantly different.The contents of caffeine and gallic acid in C.tachangensis form Pu an were average to 28.53 mg·g^(-1) and 0.29 mg·g^(-1),which were significantly higher than those from Panzhou.The contents of theacrine,C and EC in C.tachangensis from Panzhou were average to 22.88 mg·g^(-1),2.37 mg·g^(-1) and 36.83 mg·g^(-1),which were extremely significantly higher than those from Pu an.The correlation analysis showed that there were strong correlation between 11 biochemical components,with 14 pairs showing significant or extremely significant positive correlations,16 pairs showing significant or extremely significant negative correlations.Based on the hierarchical clustering of 11 biochemical components,40 C.tachangensis germplasm resources could be divided into 3 groups.All 30 C.tachangensis germplasm resources from Panzhou were composed groupⅠand the main biochemical characteristics were high content of theacrine and C,and low content of caffeine;10 C.tachangensis germplasm resources from Pu an were separated into 2 categories,GT-PA-03 and other 6 germplasm resources constituted groupⅡ,the main biochemical characteristics were high content of caffeine,EC,ECG,and low content of theacrine,gallic acid,EGC,C,EGCG;GT-PA-01,GT-PA-02 and GT-PA-09 were composed groupⅢand the main biochemical characteristics were high content of gallic acid,EGC and EGCG.OPLS-DA results showed that caffeine,theacrine and gallic acid were the key biochemical factors to distinguish C.tachangensis germplasm resources from Pu an and Panzhou.A series of specific genetic resources were screened out from the 40 C.tachangensis germplasm resources,which included three high theacrine(>25.0 mg·g^(-1))germplasm resources,two high GCG(>15.0 mg·g^(-1))germplasm resources,three high ECG(>80.0 mg·g^(-1))germplasm resources,three high EC(>50.0 mg·g^(-1))germplasm resources.