title: Conditional changes enhanced production of bioactive metabolites of marine derived fungus Eurotium rubrum.
abstract: Metabolites of marine derived fungus Eurotium rubrum MPUC136 differed between cultivation on wheat medium and Czapek-Dox agar medium. Melanin synthesis inhibitory activity of crude extract of culture on wheat medium showed stronger activity than that of crude extract of culture on Czapek-Dox agar medium. A new diketopiperazine compound isoechinulin D (1) and eight reported diketopiperazines (2-9) were isolated from the crude extract of wheat medium. The structure of 1 was established using NMR, MS and IR methods. 2-5 inhibited melanogenesis using B16 melanoma cells (IC50=68, 2.4, 83, 9.1μM each). Structure-Activity-Relationships of diketopiperazines (1-10) indicated the importance of the prenyl groups at C-2, C-5 and C-7, the vinyl group at C-12 to C-25 and the sp2carbons at C-8 and C-9. Isolated compounds (1-9) were not or slightly observed from the extracts of Czapek-Dox agar medium by HPLC analysis, suggesting that different cultivation processes could affect metabolism and enhance bioactivities.
authors.affiliation: Department of Pharmacognosy and Phytochemistry, Meiji Pharmaceutical University, Noshio 2-522-1, Kiyose-shi, Tokyo 204-8588, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kamauchi
authors.affiliation: Department of Pharmacognosy and Phytochemistry, Meiji Pharmaceutical University, Noshio 2-522-1, Kiyose-shi, Tokyo 204-8588, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kinoshita
authors.affiliation: Department of Microbiology, Meiji Pharmaceutical University, Noshio 2-522-1, Kiyose-shi, Tokyo 204-8588, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Sugita
authors.affiliation: Department of Pharmacognosy and Phytochemistry, Meiji Pharmaceutical University, Noshio 2-522-1, Kiyose-shi, Tokyo 204-8588, Japan. Electronic address: kiyotaka@my-pharm.ac.jp.
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Koyama
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid; D055325:Eurotium / Q000737:chemistry*; D008386:Marine Biology; D051379:Mice; D013057:Spectrum Analysis / Q000379:methods; D013329:Structure-Activity Relationship
keywords: Alkaloid; Diversity; Marine derived fungi; Melanogenesis; Metabolite