Studies on the Structure and Biosynthesis of Tridentoquinone and Related Meroterpenoids from the Mushroom Suillus tridentinus (Boletales)

✍ Scribed by Martin Lang; Andrea Mühlbauer; Claudia Gräf; Jürgen Beyer; Susanne Lang-Fugmann; Kurt Polborn; Wolfgang Steglich

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 380 KB
• Volume: 2008
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/ejoc.200700908

✦ Synopsis

Abstract

Tridentoquinone (1), the main pigment of Suillus tridentinus, is accompanied by the known meroterpenoid bolegrevilol (3) and a dimer, tridentorubin (5). The absolute configuration of 1 was unambiguously established by a single‐crystal X‐ray analysis of the corresponding (–)‐camphanoate. The structure of 5 was elucidated by 2D NMR techniques including a 2D INADEQUATE experiment. Feeding experiments with [1‐^13^C]‐labeled 4‐hydroxybenzoic acid (6*) and 3,4‐dihydroxybenzoic acid (7*) proved the incorporation of these precursors into all three metabolites. Tridentoquinone (1) was monolabeled at C‐1 suggesting the formation of the ansa ring by oxidative cyclisation of 2‐geranylgeranyl‐6‐hydroxybenzoquinone (10). This was supported by the isolation of the expected intermediate, deoxytridentoquinone (11), from the mushroom extract. Tridentorubin (5) may be formed by addition of precursor 10 to tridentoquinone (1). This hypothesis is backed up by the in vitro formation of an analogous product 13 from 1 and 1,4‐benzoquinone. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)