MeNH(CH2)(6)NHMe2 was alkylated with RBr (R = CnH2n+1, n = 10, 12, 14 and 16) in MeCN (K2CO3) and then reacted with 1,3-propanesultone to resp. [(CH2)(3)N-circle plus RMe(CH2)(3)SO3 circle minus](2) sulfobetaines. Their structure was confirmed by H-1 and C-13 NMR spectra and elementary anal. The products showed high susceptibility to biodegradn. but no biocidal efficiency except for the compd. with R = C10H21 and C12H25 active against some bacteria.