Synthesis of fructans by fructosyltransferase from the tuberous roots of Viguiera discolor (Asteraceae)

• Main Authors: Itaya N.M., Figueiredo-Ribeiro R.C.L., Buckeridge M.S.
• Format: Article
• Language: English
• Published: Associação Brasileira de Divulgação Científica 1999-01-01
• Series: Brazilian Journal of Medical and Biological Research
• Subjects: inulin; fructosyltransferase; fructan biosynthesis; Viguiera discolor; Asteraceae
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999000400010

Sucrose:sucrose fructosyltransferase (SST) and fructan:fructan fructosyl-transferase (FFT) activities from crude extracts of tuberous roots of Viguiera discolor growing in a preserved area of cerrado were analyzed in 1995-1996. SST activity was characterized by the synthesis of 1-kestose from sucrose and FFT activity by the production of nystose from 1-kestose. The highest fructan-synthesizing activity was observed during early dormancy (autumn), when both (SST and FFT) activities were high. The increase in synthetic activity seemed to start during the fruiting phase in the summer, when SST activity was higher than in spring. During winter and at the beginning of sprouting, both activities declined. The in vitro synthesis of high molecular mass fructans from sucrose by enzymatic preparations from tuberous roots collected in summer showed that long incubations of up to 288 h produced consistently longer polymers which resembled those found in vivo with respect to chromatographic profiles.