秃房茶嘌呤生物碱组成特点及生化品质成分的研究

该研究采用分光光度法和高效液相色谱法,分不同叶位对秃房茶(Camellia gymnogyna)的嘌呤生物碱组成特点以及茶多酚、儿茶素组分、游离氨基酸、黄酮、茶氨酸等生化品质成分进行了测定。结果表明:秃房茶的嘌呤生物碱组成及配比显著区别于茶叶植物凤凰单从(C.sinensis),同时具有可可碱、咖啡碱和苦茶碱三种组分,而且可可碱含量最多,为13.46~39.72 mg·g~(-1),咖啡碱含量最低,为0.51~2.02 mg·g~(-1),苦茶碱含量介于两者中间并随芽叶成熟度增加而升高。茶叶植物只存在咖啡碱和可可碱,含量变化分别为22.22~53.13 mg·g~(-1)和0.47~12.82 mg·g~(-1)。在相同叶位中,秃房茶儿茶素组分含量变化规律为EGCGCECGEGCECGCCGGCG,且儿茶素总量、酯型儿茶素含量均低于茶叶植物,而非酯型儿茶素总量接近,保持为40~50 mg·g~(-1)。除黄酮含量在各叶位变化趋势不大外,其他品质成分含量变化基本符合第1叶芽第2叶第3叶第4叶,一芽二叶的含量介于第1叶和第2叶之间的规律,而茶多酚、黄酮、茶氨酸等其它品质成分含量均低于茶叶植物。该研究首次明确了秃房茶主要生化品质成分变化规律,特别是嘌呤生物碱的组成及配比特点,且含有特征性成分—苦茶碱。该研究结果为生物碱代谢机理、特异茶加工、功能成分开发、低咖啡碱资源、选育种等提供了优良材料。

Composition characteristics of purine alkaloids and biochemical components of Camellia gymnogyna

In order to investigate components of purine alkaloids and contents of tea polyphenols, catechins, free amino acids, flavonoids and theanine(Thea)in different leaf positions of Camellia gymnogyna were studied by the methods of ultraviolet spectrophotometry and high performance liquid chromatography(HPLC). The results showed that the component of purine alkaloids, consisted of caffeine(Caf), theobromine(Tb)and theacrine(Tc), had significant differences between the C. sinensis and C. gymnogyna. Tb content was the highest, reached 13.46-39.72 mg·g^-1, Caf content was the lowest, only kept 0.51-2.02 mg·g^-1, and the content of Tc increased with leaves maturing. However, C. sinensis only contained caffeine and theobromine, whose contents respectively varied from 22.22 to 53.13 mg·g^-1, 0.47 to 12.82 mg·g^-1. In the same tea leaf position, catechins component of C. gymnogyna were as follows: EGCG>C>ECG>EGC>EC>GC>CG>GCG, and the total amount of catechins, ester-catechins were significantly lower than C. sinensis, while none-ester catechins content was almost the same, kept 40-50 mg·g^-1. The content of flavonoids demonstrated almost same in different leaf positions while other biochemical components content were as follows: 1st leaf >bud >2nd leaf >3rd leaf >4th leaf, and the contents of two leaf and a bud were between the 1st leaf and 2nd leaf content; while tea polyphenols, flavonoids, theanine and other quality components were lower than those of C. sinensis. This study clarified the changes of the main biochemical quality components of the C. gymnogyna for the first time, especially the composition and proportion of purine alkaloids, which contained the characteristic ingredient-theacrine. The research could be served as important and valuable tea tree resources, and application in alkaloid metabolism mechanism, special tea processing, functional ingredients, low caffeine resources and genetic breeding.