Actinomycines basically exhibit an inhibitory effect on both gram-positive and -negative bacteria, as well as on fungi. However, dactinomycin exhibits pronounced neoplastic action. It forms a complex with DNA due to binding with guanine-cytosine segments, and as a result, DNA-requiring synthesis of RNA is blocked. The other cytotoxic effect of actinomycin is that it prevents DNA from spiraling. In addition, actinomycin inhibits topoiso-merase II. In can be used intravenously. It is used to treat Wilms' tumors, Kaposi's and Edwin's sarcomas, lymphomas, and so on. Synonyms of this drug are actinomycin D, cos-megen, and others.

30.3.2 Bleomycins

Bleomycin: Bleomycin is a stereoisomer of 6-amino-N-[[2-[[4-[[1-[[[2-[4-(aminocar-bonyl)[2,41-bintiazol]-21-yl]ethyl]amino]carbonyl]-2-hydroxypropylamino-2-hydroxy-1,3-dimethyl-4-oxobutyl]amino-1-[[2-0-[3-O-(aminocarbonyl)-a-D-

mannopyranosyl-a-L-glucopyranosyl]oxy]-1H-imidazol-4-ylmethyl]-2-oxoethyl]-2-[1-(2,3-diamino-3-oxopropyl)-4-oxo-azethidinyl]-5-methyl-4-pyrimidincarboxamide (30.3.2)].

Bleomycin is a complex of no less than 16 glycopeptide antibiotics made from the family Streptomyces verticilus, which have different R groups [88-94]. Bleomycines exhibit antitumor, antiviral, and antibacterial activity. When bound to DNA, they disturb the spi-raling of both single and double strands of DNA. To a lesser degree, they inhibit RNA and protein synthesis. It is administered both intravenously and intramuscularly.

It is used for lymphomas, carcinomas, and sarcomas. Synonyms of this drug are blenox-ane, bleocin, and others.

30.3.3 Anthracyclines

Doxorubicin and daunorubicin are antibiotics made from microorganisms of the family Streptomyces peucetius. The structure of these anthracyclines contains an aminosaccarhide residue daunozamine attached to a naphthacenequinone nucleus. Doxorubicin differs from daunorubicin in the presence of a hydroxyl group at C14. A number of mechanisms have been suggested in which anthracyclines exhibit cytotoxicity. They cause DNA to denature, are involved in oxidation-reduction reactions, chelate bivalent cations and react with cell membranes, changing their function. They are used for severe leukemia, lymphoma, breast and ovarian cancer, and other solid tumors.

Doxorubicin: Doxorubicin, 7,8,9,10-tetrahydro-6,7,9,11-tetrahydroxy-9-hydroxyacetyl-4-methoxy-5,12-naphthacenequinon-7-(3-amino-5-methyl-2,3-dideoxy-L-lixopyranozide) (30.3.3), was isolated from a cultured fluid of S. peucetius var. caesuis [95,96], and later synthesized [97-100].

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