1990 Fiscal Year Final Research Report Summary
Carbazomycins, Antifungal Carbazole-Antibiotics Active Against Phytopathogenic Fungi. -Biosynthesis of Carbazomycin B and Structure Elucidation of the Congeners-
| Project/Area Number |
61571004
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Chemical pharmacy
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| Research Institution | Hiroshima University |
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Principal Investigator |
KANEDA Miyuki Hiroshima Univ., School of Medicine Associate Professor, 医学部, 助教授 (40019675)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Shoshiro Hiroshima Univ., School of Medicine Professor, 医学部, 教授 (40013304)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Carbazomycins / Antifungal antibiotics / Biosynthesis of carbazomycin B / Incorporation of pyruvate / Carbazomycin C / Carbazomycin D / Carbazomycin G / Carbazomycin H |
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| Research Abstract |
Carbazomycins A (II) and B (I) were isolated from Streptoverticillium ehimense as the first antibiotics having a carbazole nucleus and inhibit mainly the growth of phytopathogenic fungi.
In our previous biosynthetic studies of I, we found that the origin of all carbon atoms of the carbazole nucleus except C-1 and C-2 are derived from tryptophan, C-12 from methionine and the C^2 unit, C-1 and C-10, from acetate. In this project, we attempted to determine the origin of the unsolved C_2 unit, C-2 and C-11, by feeding experiments with ^<14>C- and ^<13>C-labeled compounds followed by measurement of radioactivity and ^<13>C NMR spectra. The results has indicated that the intact C_2 unit of C-2 and C-3 of pyruvate is incorporated into C-2 and C- 11 of I and that this C_2 unit of pyruvate is also incorporated into C-1 and C-10 probably by way of acetyl-CoA. Hence, the origin of the all carbon atoms of I has been established as shown in Fig. 1.
During the biosynthetic studies, we found six minor components, carbazomycins C (III), D (IV), E (V), F (VI), G (VII) and H (VIII). Their structures have been elucidated as shown in Fig. 2 and Fig. 3 by ^1H and ^<13>C NMR, chemical correlation and X-ray analyses.
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