- 著者
- KATSUTOSHI TAKAHASHI HISAO EKIMOTO SHOKO AOYAGI AKIKO KOYU HIROSHI KURAMOCHI OSAMU YOSHIOKA AKIRA MATSUDA AKIO FUJII HAMAO UMEZAWA
- 出版者
- JAPAN ANTIBIOTICS RESEARCH ASSOCIATION
- 雑誌
- The Journal of Antibiotics (ISSN:00218820)
- 巻号頁・発行日
- vol.32, no.1, pp.36-42, 1979 (Released:2006-04-12)
- 参考文献数
- 12
- 被引用文献数
- 30 31
Pepleomycin (PEP), 3-[(S)-1'-phenylethylamino]propylaminobleomycin has potent activity and is less pulmonary toxic than bleomycin (BLM). Biological activity and toxicity of the following degradation products of PEP have been studied in detail: the product of carbamoyl migration (ISO), the product of decarbamylation (DC), the product of ring closure of the side chain on the pyrimidine moiety (RC), the depyruvamide product (DP) and the product of an enzymatic inactivation (DA). These degradation products showed much lower activity than PEP in vitro: antimicrobial and anti-HeLa activities, inhibition of DNA synthesis in AH66 cells and the DNA strand cleavage. Acute toxicity and pulmonary toxicity were tested in mice. Results indicated much lower acute toxicity corresponding to the decreased in vitro activity when compared to PEP. DP and RC did not cause lung fibrosis in mice, while ISO and DC showed 1/2.6 and 1/5.7 degree of pulmonary toxicity, respectively, in comparison with PEP.
- 著者
- HISAO EKIMOTO HIROSHI KURAMOCHI KATSUTOSHI TAKAHASHI AKIRA MATSUDA HAMAO UMEZAWA
- 出版者
- JAPAN ANTIBIOTICS RESEARCH ASSOCIATION
- 雑誌
- The Journal of Antibiotics (ISSN:00218820)
- 巻号頁・発行日
- vol.33, no.4, pp.426-434, 1980 (Released:2006-04-12)
- 参考文献数
- 18
- 被引用文献数
- 21 22
The kinetics of the reaction of BLM-Fe(II)-O2 with DNA in the absence or presence of 2-mercaptoethanol (2-ME) were studied. The total number of bases released by BLM-Fe(II)-O2 in the presence of 2-ME increased about 6.5 times more than that in the absence of 2-ME in the reaction of 6 hours at 37°C. The molar ratios of the released bases ware little affected by the reaction time, temperature or 2-ME. Among the four bases, thymine was preferentially released. On the basis of a reaction scheme of BLM-Fe(II)-O2 with DNA, the equations were derived by the steady-state method. In the absence of 2-ME, the release of bases from DNA was dependent on the concentration of BLM-Fe(II)-O2, but independent of the concentration of DNA. In the presence of 2-ME, a biphasic reaction was observed; the first one is due to BLM-Fe (II) which originally existed and the second one is due to BLM-Fe(II) produced by the reduction of BLM-Fe(III) with 2-ME. In the second reaction, the rate of the release of bases from DNA was proportional to the concentration of BLM-Fe(II) and 2-ME, but inversely proportional to the concentration of DNA. The rate-determining step in the reaction of BLM-Fe(II)-O2 with DNA in the presence of 2-ME was found to be the reduction of BLM-Fe(III) to BLM-Fe(II). By these kinetic studies, the reaction of BLM-Fe(II)-O2 with DNA in the presence of 2-ME was elucidated to proceed in a catalytic fashion. Furthermore, the maximum number of bases released by BLM from DNA was one base per twelve to thirteen bases.