Abstract
In red petals of carnation, the main pigment was identified as 3, 5-di-O-(β-glucopyranosyl) pelargonidin 6''-O-4, 6'''-O-1-cyclic malate. Anthocyanins are known to be glycosylated by uridine diphosphate (UDP)-glucose dependent glycosyltransferase. However, some of the reactions, including 5-O-glucosylation in carnations, have not yet been elucidated. Here, we assessed to detect that sugar donor candidates in protein-free extracts from carnation petals prepared using 50% ethanol. The presence of candidate donors was tested with a crude protein extract from carnation petals using cyanidin 3-glucoside as the acceptor. After the enzyme reaction with the candidate in the crude protein extract, an additional peak was observed in a high-performance liquid chromatography chromatogram. The retention time of the peak and its ultraviolet-visible spectrum corresponded to that of cyanidin 3,5-diglucoside. This work demonstrated the presence of anthocyanin glucosyltransferase activity at 5 position using a donor that was apparently different from UDP-glucose. This research was partially supported by the Research and Development Program for New Bio-industry Initiatives.
