40 アフラトキシン生産阻害物質aflastatinに関する研究(口頭発表の部)

• 作田 庄平

  東大院農・応生化

• 池田 博幸

  東大院農・応生化

• 櫻田 賢

  東大院農・応生化

• 降旗 一夫

  東大院農・応生化

• 中山 二郎

  東大院農・応生化

• 鈴木 昭憲

  東大院農・応生化

• 小野 誠

  森永製菓研究所

• 磯貝 彰

  奈良先端大・バイオ

書誌事項

タイトル別名

• 40 STUDIES ON AFLASTATIN, A NOVEL INHIBITOR OF AFLATOXIN PRODUCTION

抄録

A novel inhibitor of aflatoxin production of Aspergillus parasiticus was isolated from the mycelial extracts of Streptomyces sp. MRI142 and termed aflastatin A (1). The molecular formula of 1 was determined as C_<62>H_<115>NO_<24>, and its structure was elucidated by NMR and chemical degradation experiments. By analyzing a variety of 2D-NMR spectra of 1, a partial polyhydroxylated structure (A) was identified. Based on the structure of A, 1 was oxidized with NaIO_4, and three fragment molecules, 2, 3 and 4, were obtained. Since all carbon atoms contained in 1 were involved in the partial and fragment structures, its carbon chain was constructed with them. Finally, the stereochemistry of a tetrahydropyran ring was determined by J values and NOEs among the ring protons. Thus, the total structure of aflastatin A was characterized as 1, which is a unique tetramic acid derivative having a highly oxygenated long alkyl chain. To determine the absolute configuration of 4, 2,4-dimethyl-1,6-hexanediol dibenzoate (6) was prepared from 4. By comparison of its CD spectrum with those of opticaly active (2R, 4S)- and (2S, 4S)-6, which were derivatized from cycloheximide, the configurations of natural 6 were determined to (2S, 4R). On the other hand, N-methylalanine from 4 was determined to have a D configuration. The incorporation experiments using ^<13>C-labeled acetate and propionate suggested that most of the C_2 and C_3 units involved in the alkyl chain moiety of 1 were biosynthesized from acetic and propionic acid. Unexpectedly, no incorporation was observed in one of the C_2 units and two of the C_4 units in the alkyl chain. Aflastatin A inhibited aflatoxin production in A. parasiticus at the concentration of 0.5μg/mL completely, but didn't inhibit its growth at the same concentration.

収録刊行物

• 天然有機化合物討論会講演要旨集

  天然有機化合物討論会講演要旨集 39 (0), 235-240, 1997

  天然有機化合物討論会実行委員会

詳細情報

• CRID: 1390282681055534720
• NII論文ID: 110006679534
• DOI: 10.24496/tennenyuki.39.0_235
• ISSN: 24331856
• 本文言語コード: ja
• データソース種別:
  • JaLC
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可