8-氧化咖啡因和嘧啶类生物碱在普洱熟茶中的存在

应用柱层析分离技术,从普洱熟茶中首次分离到8-氧化咖啡因,嘧啶类生物碱(胸腺嘧啶脱氧核苷、胸腺嘧啶和尿嘧啶) ,黄酮类配糖体(黄杞甙) ,以及简单酚类化合物(1 ,2 ,4-苯三酚、1 ,3-苯二酚和4-甲基-1 ,2-二苯酚)。由于普洱熟茶是由大叶茶经微生物后发酵生产的, 8-氧化咖啡因显然是茶叶中的咖啡因在微生物作用下形成的转化产物。胸腺嘧啶脱氧核苷亦可能是茶叶中的嘧啶类生物碱与微生物中的核苷类化合物在后发酵过程中缩合形成的。二者均为新发现的普洱熟茶的特征性成分。

The Occurrence of 8-oxocaffeine and Pyrimidine Alkaloids in Pu-Er Ripe Tea

By means of column chromatographic techniques, 8-oxocaffeine, together with pyrimidine alkaloids (deoxythymidine, thymine and uracil), flavonoidal glycoside (engeletin) and simple phenols (1, 2, 4-benzenetriol, 1, 3-benzenediol and 4-methyl-1, 2-benzenediol) were isolated for the first time from Pu-Er ripe tea. Since Pu-Er ripe tea is produced from the leaves of Camellia sinensis var.assamica by the post microbial fermentation process, the formation of 8-oxocaffeine should be due to the biotransformation of caffeine. On the other hand, deoxythymidine might be derived from the combination of pyrimidine alkaloid in tea leaves with microbial secondary metabolite. Both of them were found to be the new characteristic principles of Pu-Er ripe tea.