Calystegines in Calystegia sepium derive from the tropane alkaloid pathway

Calystegines were measured in roots and aerial parts of Calystegia sepium. The accumulation appears, developmentally regulated. Calystegine accumulati on in hairy root cultures follows growth and reaches maximal values of 1,5 mg/g dry mass. N-15-Labelled tropinone was fed to root cultures and the inc orporation of label into calystegines and further metabolites of the tropan e alkaloid pathway was measured after 2, 4 and 6 days. Pseudotropine was co mpletely labelled after 2 days, and calystegine A(3) was labelled faster th an the calystegines of the B-group. 2,7-Dihydroxynortropane also incorporat ed N-15 from tropinone and is suggested to be a by-product of the tropane a lkaloid pathway leading to calystegines. (C) 2001 Elsevier Science Ltd. All rights reserved.