Dihydrosterigmatocystin and Dihydrodemethylsterigmatocystin,New Metabolites from Aspergillus versicolor |
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Authors: | Yuichi Hatsuda Takashi Hamasaki Masayoshi Ishida Kuniaki Matsui Shinichiro Hara |
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Affiliation: | Faculty of Agriculture, Tottori University, Tottori, Japan |
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Abstract: | L-Arabinose isomerase (L-arabinose ketol-isomerase, EC 5.3.1.4) was demonstrated from the L-arabinose-grown cells of Streptomyces sp. which was isolated from sea water. The enzyme was purified by MnCl2 treatment, fractionation by polyethylene glycol and by column chromatographies on Sephadex G-150 and DEAE-cellulose. The purified enzyme was specific only for L-arabinose and the Michaelis constant for L-arabinose was 40 mM at pH 7.5. Manganese or cobalt ions were effective for the enzyme activity after dialysis against EDTA. The enzyme activity was inhibited competitively by L-arabitoI, ribitol and xylitol, of which inhibition constants were 1.1, 1.0, and 15 mM, respectively. |
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Keywords: | lactoferrin interleukin 8 polymorphonuclear leukocytes immunomodulator |
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