抗生物質の研究 (第9報)

Anhydrotetracycline体の生成と生物学的性質

抄録

It has been found that the heating of chlorotetracycline or tetracycline in dilute hydrochloric acid resulted in the facile formation of the corresponding anhydrotetracycline compounds. These substances had already been prepared by Waller and others and by Conover and others from the tetracycline compounds under drastic conditions such as by treatment with hydrogen iodide or with methanolic hydrochloric acid and their structures have already been elucidated. However, since no report has been made on their biological actions, this point was examined.
1) Antibacterial spectrum: Both showed approximately the same antibacterial action against the gram-positive and gram-negative bacteria. Antibacterial action against avian type tubercle bacilli was apparent but extremely small against human type bacilli.
2) Relationship between pH and antibacterial spectrum: High antibacterial power was shown in an acid medium.
3) Resistance of antibiotic-producing Actinomyces against these substances: Actinomyces which produce chlorotetracycline, oxytetracycline, chloramphenicol, dextromycin, actinomycin, and streptothricin do not show any resistance to the present substances.
These results suggest that the aromatization of the C-ring in the molecules of the tetracycline series compounds does not result in the loss of the antibacterial action and that such action mechanism is different from that of chlorotetracycline or oxytetracyline.