Comparison of the antitumor, immunodepressive and toxic properties of carminomycin-albumin complexes differing in carminomycin content

Bovine serum albumin (BSA) and carminomycin, an anthracycline antibiotic, were subjected to conjugation with glutaraldehyde and their complexes with various contents of the antibiotic were prepared. The molar ratios of carminomycin and BSA were 8:1, 4:1, and 2:1. The antitumor effect of the preparations was studied on the models of mouse transplantable lymphosarcoma LIO equal 1 and ascitic forms of mouse lymphadenosis NK/Ly in vivo and in vitro. Their immunodepressant effect was evaluated from the decrease in the hemagglutinin titers in the mice immunized with sheep red blood cells. It was shown that when the toxicity of the complexes was the same, their antitumor and immunodepressant activities were different. The therapeutic activity of carminomycin in the four- and eight-substituted complexes was much higher than that of carminomycin alone. It is suggested that the differences in the activity of the complexes were connected with differences in their pharmacokinetics. It was found that the chemotherapeutic properties of the complexes may have changed by variation of the number of the cytostatic residues in the albumin molecule. The findings indicate that the whole complex molecule interacts with the malignant cell and not carminomycin preliminarily detached from it.     

Thiol-dependent protective systems in alimentary prevention of the toxic effect of carminomycin

The state of the thiol-dependent systems i.e. concentration of the SH-groups, activity of glutathione reductase and glutathione-S-transferase, carminomycin antitumor and toxic effects was studied under conditions of tumor growth and carminomycin therapy with the use of prophylactic rations (PR) aimed at stimulating the cell thiol-dependent and antioxidant systems for decreasing the drug toxic action. It was shown that addition of sulfur-containing amino acids, selenium and vitamin E to the ration of healthy and tumor-bearing rats (Walker carcinosarcoma 256) induced a decrease in the level of the SH-groups in the liver just likely promoting efficient extrahepatic usage of glutathione. After administration of carminomycin a long with the PR use, the liver showed the thiol-preserving capacity evidenced by a decrease or complete elimination of the above effect of the ration. The use of PR resulted in a marked increase in the glutathione-S-transferase activity in cytosol and to a lesser extent in the liver microsomes. A regulating effect of the PR on the activity of glutathione reductase was observed: its inhibition in the healthy animals and stimulation after carminomycin administration in the heart of the healthy animals and the liver of the tumor-bearing animals.     

Synthesis and antitumor properties of carminomycin 13-cyclohexylidenhydrazone

Carminomycin 13-cyclohexylidenhydrazone (CCH) was prepared by interaction of carminomycin 13-hydrazone with cyclohexane. The antiblastomic properties of CCH were studied on mice with transplantable tumors. The preparation was administered intravenously or orally. The studies showed a high antitumor activity of CCH. When CCH was administered intravenously to mice with lymphosarcoma LIO-1, the antitumor effect selectivity of it was practically equal to that of carminomycin. When used in doses equivalent by their toxicity to those of carminomycin, CCH had practically the same inhibitory effect on sarcoma 180 as carminomycin. When used orally in doses equivalent by their toxicity to those of carminomycin, CCH was more effective than carminomycin in treatment of mice with lymphosarcoma LIO-1, sarcoma 180 and lymphadenosis NK/Ly.     

Antitumor activity of carminomycin antibiotic used orally]

Antitumor activity of karminomycin used perorally was studied with respect to 3 strains of mouse transplantable tumors, i. e. one ascitic strain of lymphadenosis NK/LI and two solid strains of lymphosarcoma L10-1 and sarcoma 180. Karminomycin was shown to have a high antitumor activity against the above tumors on its oral administration. In the experiments with lymphadenosis NK/LI the efficiency of karminomycin was higher when it was used perorally as compared to its intravenous administration. It was found that karminomycin had practically the same inhibitory effect on growth of lymphosarcoma L10-1 and sarcoma 180 on its peroral and intravenous administration in doses equivalent by their toxicity.     

Effect of the peroral use of the antitumor antibiotic, carminomycin, on the immunological reactivity of the body of animals]

Carminomycin administered orally to mice for many times in doses of 2.5 and 1.25 mg/kg induced suppression of hemagglutinine production to sheep erythrocytes and formation of immunologically competent cells in the spleen of test animals. The content of DNA and RNA in the spleen of the test animals treated with carminomycin and sheep erythrocytes was somewhat lower than that in the control mice immunized but not treated with the antibiotic. Carminomycin prolongated the life time of the skin graft by 6.5 days as compared to that of the skin homotransplant in the control animals. The oral use of carminomycin in a dose of 2.5 mg/kg induced a statistically significant decrease in the absorption capacity of the cells of the reticuloendothelial system of the animals.     

The effect of metal ions on the electrochemistry of the antitumor antibiotic streptonigrin

The effect of transition metal ions on the electrochemistry of 6-methoxy-5,8-quinolinedione (L1), 7-amino-6-methoxy-5,8-quinolinedione (L2) and the antitumor antibiotic streptonigrin (SN) was studied. In 10% methanol/water, the one-electron reduction of quinones L1 and L2 to the corresponding semiquinones is shifted to more positive potentials upon addition of one equivalent of Zn(II), Ni(II), Co(II) or Cd(II) and is consistent with formation of a 1:1 complex involving the quinone(N) and adjacent quinone(O). Similar results are observed for Cu(II) and Mn(II), but the redox chemistry is also complicated by metal-based redox chemistry. The addition of further equivalents of M(II) results in a number of different coordination and electrochemical processes including formation of 1:1 and 2:1 complexes of the quinone, semiquinone and dianion. Under similar conditions, the 1:1 SN 2,2'-bipyridyl metal complex undergoes a reversible one-electron reduction to the semiquinone. The redox potential of the quinone in SN was shifted positive in the presence of the metal ions, but both the magnitude of the shift, and the relative influence of the metals was different to ligands L1 and L2. The changes in redox chemistry of SN compared with L1 and L2 are consistent with the formation of the 2,2-bipyridyl complexes in which there is weaker coordination to the quinone(O) in ring A of SN. These results suggest that in vivo, metal ions such as Zn(II), Cu(II) and Mn(II) facilitate the initial reduction of streptonigrin to the semiquinone by capturing the semiquinone after SN is reduced by biological reductants.     

Comparative cytogenetic action of the antitumor antibiotics, carminomycin and rubomycin

A comparative mutagenic effect of karminomycin and rubomycin in LD50 on the cells of the rat bone marrow (71 animals) was studied. It was found that karminomycin had a higher and more prolonged mutagenic effect than rubomycin. Both antibiotics induced mainly chromatin deletions and not so frequent reconstructions. They are probably identical with respect to their mechanism of action on chromosomes.     

Immunomodulating mechanism of the antitumor effect of asterin

It was shown that asterin therapy performed on a model of spontaneous metastasis markedly changed the content of the thymus serum factor in mice and normalized its level. The inducing mechanism of the drug's antitumor action was realized both at the stage of the metastatic postinvasion phase and during its terminal period which was probably due to an increase in the influence of the thymus on the immune system and evident from an increase in the therapeutic action of the drug.     

Mechanism of the myeloinhibitory effect of carminomycin]

The proliferative activity and level of aberrant mitoses in the cells of the bone marrow were studied experimentally on 223 noninbred mice treated with carminomycin administered intraperitoneally in single (LD50) and repeated doses. When the antibiotic was used in a single dose the values of the mitotic activity of the bone marrow elements did not correspond to the severity of depression and thir quantitative composition, which was explained by an impairement of the mitosis quality and possible interkinetic destruction of a significant part of both erythroid and immature myeloid cells capable of division at early stages after the exposure. At the same time the level of the bone marrow devastation under conditions of the treatment with repeated doses was mainly determined by inhibition of the erythronormoblast proliferative activity.     

Teichoic acid from the cell wall of Actinomadura carminata--a producer of the antibiotic carminomycin

The cell walls of Actinomadura carminata, producing the antibiotic carminomycin, contain a poly(glycerol phosphate) teichoic acid. The polymer belongs to 1,3-type and consists of about 8 glycerol phosphate units, two of them have 2-acetamido-2-deoxy-alpha-D-galactopyranosyl substituent and one--3-O-methyl-beta-D-galactopyranosyl-(1----3)-2- acetamido-2-deoxy-alpha-D-galactopyranosyl residue at C2 of glycerol. The structure of the polymer was established by chemical analysis and 13C-NMR spectroscopy. The teichoic acid accounted for about 10% of the cell wall dry weight. 3-O-methylgalactose in the structure of the teichoic acid was found for the first time.     

Preparation of dihydrocarminomycin and a comparison of its antitumor activity with the activity of carminomycin]

A dihydro derivative of karminomycin was prepared using chemical reduction with potassium boron hydride. When dihydrokarminomycin was administered intravenously to healthy albino mice in a single dose it practically showed the same toxicity as karminomycin. However, unlike the latter dihydrokarminomycin induced the death of the animals at later periods of time. Studies on mice with transplantable tumours showed high antitumor activity of dihydrokarminomycin against lymphosarcoma L10-1, sarcoma 180, Garding-Passy melanoma, lymphoid leukosis L-1210 and lymphocytal leukosis P-388. In treatment of the mice with leukosis L-1210 and Garding-Passy melanoma dihydrokapminomycin was much inferior by its efficiency than karminomycin.     

链霉菌AC-57及其产生的阿克拉霉素A的研究

During the course of screening for new antitumor antibiotics, a new anthracycline antibiotic--aclacinomycin A was separated from the broth and mycelium of Streptomyces AC-57. The strain AC-57 was isolated from the soil collected in the Shanghai suburbs. According to its culture and physiological characteristics the producer was identified as Str. galilaeus AC-57. The broth and mycelium were extracted and treated with solvents as usual way. The aclacinomycin A was separated by silica-gel column chromatography eluted with chrolo-form-methanol. Aclacinomycin A, its aglycone and sugar components were identified by comparison of their physico-chemical and spectral data (MS, UV, IR, 1H-NMR, and 13C-NMR) with authentic compound, purified from the market sample.     

Physico-chemical characteristics of the new antitumor antibiotic virenomycin

Virenomycin, a new crystalline antitumor antibiotic was isolated from the mycelium of Streptomyces virens. The antibiotic contained: C 64.87 per cent, H 5.66 per cent, methoxylic groups 9.5 per cent. The melting temperature was 255-260 degrees (dec.), [alpha]20D=-17 (c 0.142, chloroform). Virenomycin had a complex UV spectrum with lambdamax. 245 (677), 265 (453), 275 (542), 287 (507), 395 (222) nm. A chromofor fragment and carbohydrate (C7H14O5) were found in the methanolysis products. Virenomycin was close to antibiotic c B-21085 BY THe physico-chemical properties and differed from it in the character of the UV spectrum and the values of the specific absorption, as well as by the optic rotation in dimethyl sulphoxide and acetic acid.     

One-electron reduction of an anthracycline antibiotic carminomycin by a human erythrocyte redox chain

Human erythrocyte membranes catalyse the NAD(P)H-dependent generation of the semiquinone of an adriamycin-type antibiotic carminomycin under anaerobic conditions. The maximal yield of the antibiotic radical is about 4-fold higher in the presence of NADPH than of NADH. The possible significance of the antibiotic reduction to the semiquinone by a human erythrocyte membrane redox chain for the clinical usage of these antibiotics is discussed.     

Comparative characteristics of the antitumor and immunodepressive activity of carminomycin on the L-1210 experimental model]

The antitumor activity of carminomycin was estimated by the number of lymphoma colonies formed in the spleen of DBA/2 mice on their inoculation with the bone marrow cells from mice with transplantable leukemia L-1210. The immunodepressive properties of carminomycin were determined by the number of the antibody forming cells in the spleen of CBA and DBA/2 mice with leukemia L-1210 after immunization with sheep red blood cells. It was found that in a single dose of 1.5 mg/kg carminomycin inhibited the lymphoma colonies by 50 per cent. The maximum immunodepressive effect was observed when carminomycin was used in a single dose of 1.5 mg/kg 48 hours after the antigen stimulation. In this case the number of the antibody forming cells in DBA/2 mice with leukemia L-1210 was lower than that in CBA mice without leukemia.     

Preliminary crystallographic study of macromomycin: The apoprotein of the antitumor antibiotic auromomycin

Macromomycin (M_r 12,000) is the apoprotein of the antitumor drug auromomycin, which inhibits DNA synthesis by causing single-strand breaks in DNA. Two orthorhombic crystal forms of macromomycin have been observed. The platelike crystals of one form belong to space group P2₁2₁2₁, with cell dimensions $\text{a = 48·92}\text{A}\text{?}\text{, b = 54·71}\text{A}\text{?}\text{, c = 103·31}\text{A}\text{?}\text{, Z = 8}$. The crystals of the second form are needle-shaped, and belong to space group P2₁2₁2, with cell dimensions $\text{a = 46·1}\text{A}\text{?}\text{, b = 54·4}\text{A}\text{?}\text{, c = 41·2}\text{A}\text{?}\text{, Z = 4}$. At this point in time, the platelike crystals appear the most suitable for continued crystallographic studies.