The new anthracyclines 4-O-demethyl-l1-deoxydoxorubicin, 4-O-demethyl-l1-deoxydaunorubicin along with its 13-dihydro and 13-deoxo analogues are the main components of the anthracycline complex produced by cultures of Streptomyces peucetius var. aureus. They were isolated by solvent partition, separated by column chromatography and characterized by chemical and physical methods. Among these new anthracyclines, displaying antibacterial and cytotoxic activity "in vitro", 4-O-demethyl-11-deoxydoxorubicin and the corresponding daunorubicin analogue were also active against experimental tumors.
Experientia 38 (1982), Birkhauser Verlag, CH-4010 Basel/Switzerland vitro 17. There is also growing evidence of the interaction of the 2 vitamins in animal tissues. In some conditions, vitamin C can improve a-tocopherol metabolism; in others it may increase the demand of the body for vitamin E 18-2~ Decreased a-tocopherol content in the liver, lungs and kidneys of guinea-pigs with chronic marginal vitamin C deficiency suggests that in these organs a-tocopherol replaced the missing ascorbic acid in some redox-processes. There is also a possibility that in conditions of long-lasting 1455 low ascorbate levels in the above organs a-tocopherol is more susceptible to oxidation to quinons. In the light of known relations between the plasma levels of lipids and vitamin E 4-6, the absence of changes in the plasma level of vitamin E in vitamin C-deficient guineapigs, which showed a nearly 4-fold increase in triglyceridaemia, is surprising. The results suggest that chronic marginal deficiency of vitamin C can lead also to relative deficiency of vitamin E.Summary. Nucleating agents are found to be present in the haemolymph of the common mussel Mytilus edulis. Such substances are found only during winter, and they cause the haemolymph to freeze at temperatures around -6 ~ In summer supercooling points are around -15 ~ The mussel Mytilus edulis is commonly found in the intertidal zone in arctic and temperate regions. In winter, such sessile invertebrates are exposed to temperatures down to -30 C for a period of 1-6 h twice dailyLMytilus edulis is reported to be freeze-tolerant 3, and ice-formation is shown to take place in the extracellular compartments 4'5. Insects tolerant to freezing are shown to have nucleating agents in the haemolymph 6,7. The nucleating agents are
A new antitumor antibiotic, 13-deoxycarminomycin, has been isolated from the anthracycline complex produced by Streptomyces peucetius var. carminatus (ATCC 31502), a biochemical mutant of Streptomyces peucetius var. caesius, the doxorubicin-producing microorganism. The new anthracycline, showing antibacterial and cytotoxic activity in vitro, was found active against P-388 murine leukemia.
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