Structural specificity of the triamines sym-homospermidine and aminopropylcadaverine in stimulating growth of spermidine auxotrophs of Escherichia coli.

sym-Homospermidine (HSpe) was compared with its structural isomer, aminopropylcadaverine (AP5), and the naturally-occurring triamine, spermidine (Spe), in its ability to stimulate the growth of Spe auxotrophs of Escherichia coli. HSpe was taken up by the cells, but was less effective than Spe in stimulating growth. In at least one E. coli auxotroph, HSpe was also less effective than AP5.