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Surup F, Kuhnert E, Böhm A, Pendzialek T, Solga D, Wiebach V, Engler H, Berkessel A, Stadler M, Kalesse M. The Rickiols: 20-, 22-, and 24-membered Macrolides from the Ascomycete Hypoxylon rickii. Chemistry 2018; 24:2200-2213. [PMID: 29168908 DOI: 10.1002/chem.201704928] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Indexed: 11/10/2022]
Abstract
In preceding studies the neotropical ascomycete Hypoxylon rickii turned out to be a prolific source of new secondary metabolites, considering that we had obtained terpenoids with five different scaffolds along with a series of terphenyls. From the mycelial extracts of a 70 L scale fermentation of this strain we additionally isolated nine new macrolides (1-9) by RP-HPLC. The planar structures were elucidated by NMR spectroscopy complemented by HR-ESIMS. The relative configurations were assigned by J-based configuration analyses and confirmed by Kishi's Universal Database. Subsequently, the absolute configurations were assigned by Mosher's method using the shift analysis of a tetra-MTPA derivative. For rickiol A (1) and E (5) we observed transesterification of 20-membered ring structures to 22-membered isomers rickiol A2 (6) and E2 (7), and to 24-membered isomers rickiol A3 (8) and rickiol E3 (9), respectively. Cytotoxic effects and moderate antibiotic activity against Gram-positive bacteria were observed for 1-8 and 1-6 and 8, respectively. The total synthesis of rickiol E3 (9) established easier access to these compounds.
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Affiliation(s)
- Frank Surup
- Microbial Drugs, Helmholtz Centre for Infection Research GmbH (HZI), Inhoffenstraße 7, 38124, Braunschweig, Germany.,Partner site Hannover-Braunschweig, German Centre for Infection Research Association (DZIF), Inhoffenstraße 7, 38124, Braunschweig, Germany
| | - Eric Kuhnert
- Microbial Drugs, Helmholtz Centre for Infection Research GmbH (HZI), Inhoffenstraße 7, 38124, Braunschweig, Germany
| | - Andreas Böhm
- Institute for Organic Chemistry, Leibniz Universität Hannover, Schneiderberg 1B, 30167, Hannover, Germany.,Drug Research (BMWZ), Leibniz Universität Hannover, Schneiderberg 1B, 30167, Hannover, Germany
| | - Tim Pendzialek
- Institute for Organic Chemistry, Leibniz Universität Hannover, Schneiderberg 1B, 30167, Hannover, Germany.,Drug Research (BMWZ), Leibniz Universität Hannover, Schneiderberg 1B, 30167, Hannover, Germany
| | - Danny Solga
- Institute for Organic Chemistry, Leibniz Universität Hannover, Schneiderberg 1B, 30167, Hannover, Germany.,Drug Research (BMWZ), Leibniz Universität Hannover, Schneiderberg 1B, 30167, Hannover, Germany
| | - Vincent Wiebach
- Microbial Drugs, Helmholtz Centre for Infection Research GmbH (HZI), Inhoffenstraße 7, 38124, Braunschweig, Germany.,Institut für Chemie, Technische Universität Berlin, Müller-Breslau-Straße 10, 10623, Berlin, Germany
| | - Hauke Engler
- Department of Chemistry, Organic Chemistry, Cologne University, Greinstraße 4, 50939, Cologne, Germany
| | - Albrecht Berkessel
- Department of Chemistry, Organic Chemistry, Cologne University, Greinstraße 4, 50939, Cologne, Germany
| | - Marc Stadler
- Microbial Drugs, Helmholtz Centre for Infection Research GmbH (HZI), Inhoffenstraße 7, 38124, Braunschweig, Germany.,Partner site Hannover-Braunschweig, German Centre for Infection Research Association (DZIF), Inhoffenstraße 7, 38124, Braunschweig, Germany
| | - Markus Kalesse
- Institute for Organic Chemistry, Leibniz Universität Hannover, Schneiderberg 1B, 30167, Hannover, Germany.,Drug Research (BMWZ), Leibniz Universität Hannover, Schneiderberg 1B, 30167, Hannover, Germany.,Medicinal Chemistry, Helmholtz Centre for Infection Research GmbH (HZI), Inhoffenstraße 7, 38124, Braunschweig, Germany
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