1-pyrroline + propane-1,3-diamine + AH2 => spermidine + A
1-pyrroline + propane-1,3-diamine + ah2 => spermidine + a
1-pyrroline + propane-1,3-diamine + AH2 => spermidine + A
1-pyrroline + propane-1,3-diamine + ah2 => spermidine + a