“…The methods used for linking daunomycin to macromolecules have involved (a) cleavage of the bond between C-3 and C-4 of daunosamine producing carbonyl groups capable of reacting with the free amino groups of the protein (3,5,7,10,23,27), (b) reaction at the amino group of the amino-sugar moiety (17,24) using the crosslinking agents glutaraldehyde (8,9,19,27,28), carbodiimide (9, 25, 27), SPDP (21), and MBS (4), or (c) attachment to the methyl ketone side chain of the aglycon by nucleophilic substitution on its 14-bromo derivatives (6,16,21). Attachment of daunomycin was also achieved by the introduction of a peptidyl (11,12,18), maleyl (14), succinyl (15), or acid-labile cis-aconityl (13,14,21,29) spacer.…”