ABSTRACT
Twelve new milbemycins have been isolated and characterized from some strains derived from Streptomyces hygroscopicus subsp. aureolacrimosus SANK 60286 and SANK 60526. The metabolites 1 approximately 4 and 9 approximately 11 were produced by strain RM28D-688 SANK 60797 as minor products. The metabolites 5 approximaetly 8 were obtained from a broth of strain 57-338 SANK 61796. Strain MK-1391 SANK 62896 was used for the production of metabolite 12. The new metabolites, eight alpha-class and four beta-class compounds, have new structural features. For example, milbemycins alpha26 and alpha27, have the 26-hydroxy moiety, and other derivatives (milbemycins alpha20 approximately 23) have different side chains at the C-26 position from those of milbemycins alpha11 and alpha14. In addition, 5-hydroxylmilbemycin beta7 (beta12), involved in the major biosynthetic pathway of 25-methyl and 25-ethyl milbemycins, was discovered.
Subject(s)
Streptomyces/metabolism , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/metabolism , Fermentation , Macrolides , Magnetic Resonance Spectroscopy , Mass Spectrometry , Molecular StructureABSTRACT
The accuracy of death certificate diagnoses of cancer in the fixed population of about 100,000 samples in Hiroshima and Nagasaki was determined for the period 1961 approximately 1970 by comparison with autopsy findings. In general, when the death certificate listed cancer as a cause of death it was found at autopsy in a high proportion of cases. However, cancer was not always reported on death certificates, indicating that cancer occurs more frequently than recorded by official mortality statistics. Older persons, persons who die at home, and persons with certain cancers are more likely not to have cancer named on their death certificates. It is estimated that in the 10,749 deaths occurring at home or in hospital, there were 32% more deaths due to cancer than certified on death certificates (3,095 vs. 2,345) and for persons aged 70 or more dying at home it is estimated there were 55% more stomach cancer (269 estimated vs. 174 listed) and 244% more lung cancer (141 estimated vs. 41 listed) than were certified on death certificates. The death certificate is not a good source of information for cancer of the cervix because many cases of this disease reported on death certificates as cancer of the uterus. This practice needs to be taken into account in the use of mortality data for cervical cancer in Japan.
