SYNTHESIS OF C-13-DILABELED 4-COUMAROYLSPERMIDINES

Five C-13-dilabeled constitution isomers of 4-coumaroylspermidines wer e prepared in nine to eleven steps: N-1,4-di[(E)-4-coumaroyl]-(5,8-C-1 3(2))spermidine (13b), N-1-[(E)-4-coumaroyl]-(5,8-C-13(2))spermidine ( 17b), N-1,8-di[(E)-4-coumaroyl]-(1,4-C-13(2))spermidine (20b), N-4-[(E )-4-coumaroyl]-(1,4-C-13(2))spermidine (24b) and 1,4,8-tri[(E)-4-couma royl]-(5,8-C-13(2))spermidine (26). The two C-13-atoms were subsequent ly introduced using labeled potassium cyanide. The synthesis proceeds through stepwise construction of the polyamine backbone including prot ection and deprotection steps of the amino functions. Based on H-1-H-1 NOE interactions, the preliminary study of their binding reveals that 20b binds to tRNA in the. same way as spermidine does, whereas 24b an d 26 do not-show any NOE effects with the tRNA protons. (C) 1998 Elsev ier Science Ltd. All rights reserved.