[structure: see text] A spirobisnaphthalene derivative with a new spiro-nonadiene skeleton, spiro-mamakone A (1), has been isolated from the extract of a cultured nonsporulating fungal endophyte derived from the New Zealand native tree Knightia excelsa (rewarewa). The carbon skeleton of spiro-mamakone A represents a new structural entity and an intriguing addition to the structurally diverse spirobisnaphthalene group of compounds. spiro-Mamakone A is potently cytotoxic and is also antimicrobial.
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http://dx.doi.org/10.1021/ol060434k | DOI Listing |
J Org Chem
August 2018
Graduate School of Pharmaceutical Sciences , Tohoku University, 6-3 Aza-aoba, Aramaki , Aoba-ku , Sendai 980-8578 , Japan.
Spiromamakone A is a racemic natural product having a naphthyl acetal group on a spiro[4,4]nonadiene skeleton. Its total synthesis was achieved by double oxa-Michael addition of 1,8-dihydroxynaphthalene to 2-(1-bromoalkylidene)-4-isopropoxy-4-cyclopentene-1,3-dione, which was prepared by palladium(II)-catalyzed ring expansion of 4-(1-alkynyl)-4-hydroxy-3-isopropoxy-2-cyclobuten-1-one, and a subsequent intramolecular aldol reaction. The synthesis using optically active intermediates enabled identification of the racemization step of spiromamakone A and revealed that spiromamakone A and spiropreussione A are identical; the latter had been reported as a constitutional isomer of the other.
View Article and Find Full Text PDFOrg Biomol Chem
October 2008
Department of Chemistry, University of Canterbury, Christchurch, New Zealand.
An exploration of the chemistry of the spiro-mamakone system, exemplified by the cytotoxic, fungal metabolite spiro-mamakone A, is presented. The first reported synthesis of the spiro-mamakone carbon skeleton was achieved, as well as the synthesis of a variety of closely related analogues of the natural product. Biological testing of the synthetic analogues generated a structure-activity profile for the natural product, establishing the importance of the enedione moiety to biological activity.
View Article and Find Full Text PDFOrg Lett
May 2006
Department of Chemistry, University of Canterbury, Christchurch, New Zealand.
[structure: see text] A spirobisnaphthalene derivative with a new spiro-nonadiene skeleton, spiro-mamakone A (1), has been isolated from the extract of a cultured nonsporulating fungal endophyte derived from the New Zealand native tree Knightia excelsa (rewarewa). The carbon skeleton of spiro-mamakone A represents a new structural entity and an intriguing addition to the structurally diverse spirobisnaphthalene group of compounds. spiro-Mamakone A is potently cytotoxic and is also antimicrobial.
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