著者

我妻 勉 赤間 勉 奈良 真二 中井 龍一郎 小川 はる美 斎藤 裕 池田 俊一 松宮 茂樹 大瀧 静夫 神田 裕

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 43 (ISSN:24331856)

巻号頁・発行日

pp.431-436, 2001-09-01 (Released:2017-08-18)

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In the course of our search for new antitumor agents from microorganisms, the fungus Acremonium sp. KY4917 was found to produce novel compounds. Two novel compounds, UCS1025A (1) and B (2), were isolated from the culture broth by chromatographic methods. Molecular formulae of 1 and 2 were determined to be C_<20>H_<25>NO_5 and C_<20>H_<25>NO_6 from HRFAB-MS data, respectively. Structures of 1 and 2 were elucidated on the basis of spectroscopic methods, mainly by detailed analyses of their NMR spectra. Absolute stereochemistry of 1 was established by an X-ray crystallographic analysis of the 3'-bromo derivative 3'. As a result of spectroscopic analyses and chemical transformations of 1, the unique chemical equilibrium of 1 was found out. Three tautomeric isomers of 1 have been identified to be ketone 1a in CDCl_3 by NMR analyses, enol 1b by an X-ray crystallographic analysis, and enedione 1c in an aqueous buffered solution, respectively. UCS1025A (1) exhibited antimicrobial activity against Gram-positive bacteria, Staphylococcus anreus, Bacillus subtilis and Enterococcus hirae, and Gram-negative bacterium, Proteus vulgaris with the MIC values ranged from 1.3μg/mL to 5.2 μg/mL, and antiproliferative activity against human tumor cell lines (A431 and MCF-7) with the IC_<50> values 55 μM and 21 μM, respectively. In contrast, UCS1025B (2) showed weak antimicrobial and no antiproliferative activity.