The Role of Diglycosides as Tea Aroma Precursors: Synthesis of Tea Diglycosides and Specificity of Glycosidases in Tea Leaves
作者:Sachiko Matsumura、Shunya Takahashi、Mariko Nishikitani、Kikue Kubota、Akio Kobayashi
DOI:10.1021/jf960852b
日期:1997.7.1
Two general synthetic routes were established in order to synthesize two diglycosides, primeverosides (1) and vicianosides (2), found in tea leaves. Procedure 1 is based on the Koenig-Knorr type of condensation of aglycon alcohols and 1-alpha-bromohexabenzoylprimeverose (6) and is suitable for the condensation of primary alcohols. Procedure 2 is to combine tribenzoyl-beta-D-glucoside (8) and 1-alpha-bromotribenzoylxylose (4). The primeveroside of a tertiary alcohol was synthesized by this method which is also applicable to the synthesis of vicianosides. The hydrolysis rate of each of the 12 synthesized glycosides by a crude tea enzyme was evaluated, which suggest that the main glycosidase is primeverosidase and the enzyme mixture shows substrate specificity to both the carbohydrate and aglycon moieties.