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Condensation of the antitumor antibiotic carminomycin with oxidized chitosan in the presence of sodium borohydride provided a new conjugated antibiotic. A ring involving a N atom from the 3′ amino group of the antibiotic sugar moiety and the residue of the oxidized glucosamine ring of chitosan was formed during reductive alkylation. The resultant compound was characterized by IR and UV-VIS spectra which support the conjugate structure. The amount of carminomycin bound to the matrix was 25.2% w/w or 391 carminomycin residues. The biological activity of the carminomycin-chitosan conjugate showed an antibacterial action against Bacillus subtilis on the level of the initial antibiotic. Implanted lymphoid leucosis L1210 and lymphocytic leucosis P388 in hybrid mice BDF1 showed: a T/C = 242.9 (P388) (for free carminomycin T/C = 177.9%) and a T/C = 201.4 (L1210) (for the free drug T/C = 179.85%).

Chitosan is stepwise treated with periodic acid, urea and formaldehyde and then introduced hydroxymethyl groups reacted with tetracycline and carminomycin. The conjugates obtained are fully soluble in dirnethylforrnamide in contrast to the ji·ee chitosan. The conjugate of chitosan with tetracycline preserves almost ful(v the antibacterial activity of the free tetrac_vc-line. An enhenced antitumour activity and decreased toxicity of carminomycin are detected after its conjugation with chitosan.

Condensation of the antitumor antibiotic epirubicin with oxidized chitosan provided a new conjugated antibiotic. The resultant compound was characterized by IR and UV-Visspectra with support the conjugate structure. The amount of epirubicin bound to the matrix was 22.5 % or 315 epirubicin residues. The biological activity of epirubicin-chitosan conjugate showed an antibacterial action against Bacillus Subtilis AT 6633 on the level of the initial antibiotic. The ascetic form of lymphocytic leukemia P 388 and lymphoid leukemia L1210 (transplantation dose 10 6 tumor cells) in hybrid mice BDF 1 was used as leukemic model. Antileukemic activity of the studied conjugate was found with a clear " dose-effect" correlation. The criterion "increase of live span" is maximally 342.1 % in P338 and 371.5 % in L1210 for the conjugate in comparation with maximally 179.0 % in P388 and 197.2 % in L1210 for the free epirubicin. The conjugate showed lower toxicity and higher therapeutic index.

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