Abstract text

X—NH—Y—NH—R¹  (I)

[wherein

• • X represents R²—SO₂— in which R² represents an optionally substituted lower alkyl group or phenyl group;
  • Y represents a group selected from the group consisting of —R³—NH—R⁴—, —R⁵—NH—R⁶—NH—R⁷—, —R⁸—NH—R⁹—NH—R¹⁰—NH—R¹¹— and —R¹²—NH—R¹³—NH—R¹⁴—NH—R¹⁵— in which R³ to R¹⁵ each independently represent a C₃ to C₅ alkylene group; and
  • R¹ represents hydrogen or an optionally substituted lower alkyl group, with the proviso that the case where X represents a tosyl group, Y represents —(CH₂)₃—NH—(CH₂)₄—NH—(CH₂)₃— and R¹ represents hydrogen is excepted].