Antimicrobial and antitumor activities of three new antibiotics and their effects on protein and nucleic acids synthesis

ABSTRACT

The anti-microbial activity, toxicity and antitumor activity of three new antibiotics were investigated in relation to their effects on protein, DNA and RNA synthesis of some gram positive and gram negative bacteria. The results indicated that one antibiotic demethyltetracycline did not show any toxic effect on normal Swiss albino mice at a concentration up to 500 mg/kg body weight, meanwhile it exhibited an in vivo antitumor effect against Ehrlich ascites tumor. However, granaticin and caeseorhodomycin showed a slight toxicity [10%] to normal Swiss albino mice at a concentration of 450 mg/kg body weight, but they did not show a significant antitumor effect against Ehrlich ascites tumor. The three tested antibiotics acted as inhibitors to protein and DNA synthesis, but they had no marked effect on RNA synthesis: