著者

通 和夫 十倉 一也 岡部 啓 江幡 光雄 大塚 英夫 松下 和弘 Lukacs G.

出版者

天然有機化合物討論会実行委員会

雑誌

天然有機化合物討論会講演要旨集

巻号頁・発行日

vol.20, pp.24-31, 1976

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Sulfur-containing peptide antibiotics, siomycins (SIM) A, B, and C isolated from Streptomyces sioyaensis are known to have structures quite similar to that of thiostrepton (TST) isolated from S. azureus. The 25-MHz ^<13>C FT NMR and 220-MHz ^1H NMR spectra of TST and SIM's were determined in CDCl_3-CD_3OD (8: 2) at various temperatures to obtain structural relationships between these antibiotics. ^<13>C signals were tentatively assigned by ^1H noise decoupling, single-frequency and noise off-resonance decouplings, and partially-relaxed FT techniques and using known chemical-shift rules, the chemical shifts of amino acids reported, and those observed for thiostreptine and a quinaldic acid derivative. Their ^<13>C spectra quite similar to each other revealed the numbers of carbon atoms and dehydroalanine (Deala) residues. It was found that (1) the signals of the Val-Deala residues in SIM's are changed to those of the Ile-Ala residue in TST, that (2) SIM-B lacks of the terminal Deala-Deala residue in the long side-chain, and that (3) SIM-C has an unknown amino-acid residue instead of the terminal Deala. On the basis of the above spectral and other chemical studies, and a tentative structure (Ia) proposed for TST by an X-ray crystallographic analysis, the structures Ib, II, and III were concluded to be assigned to TST, and SIM-A and -B, respectively.

著者

大塚 英夫

出版者

公益社団法人 日本化学療法学会

雑誌

CHEMOTHERAPY (ISSN:00093165)

巻号頁・発行日

vol.28, no.Supplement7, pp.1236-1239, 1980-11-25 (Released:2011-08-04)

参考文献数

25

著者

山田 銑一 塚原 茂男 大塚 英夫 廣崎 允位

出版者

公益社団法人 日本鋳造工学会

雑誌

鋳造工学 (ISSN:13420429)

巻号頁・発行日

vol.79, no.6, pp.291-296, 2007-06-25 (Released:2012-12-26)

参考文献数

9

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Soldering reactions are commonly observed during high pressure die casting of aluminum alloys, and involve the formation of interfacial compound between the die and cast alloy. However, discussions on the effects of composition of die steel on interfacial reaction have not been reported. In this report, reaction couples were formed between various alloy steel (SK5, SKD61, SKD11) and molten AD12. The following results were obtained,   SKD11 containing lower silicon content than that of SKD61 reduced the soldering reaction. The mass loss of SKD11 reduced than that of SKD61 in molten AD12. In molten AD12, intermetallic layer composed of Al, Fe and Si was formed in every steel. The intermetallic layer was composed of two layers; the inner layer had a lower silicon content and the outer layer a higher content.   In molten AD12, the intermetallic layer SKD61 was formed of compact and broken layers. On the other hand, SKD11 showed a compact layer and a slight broken layer, while SK5 showed a compact layer but no broken layer.