Traminines A and B, produced by Fusarium concentricum, inhibit oxidative phosphorylation in Saccharomyces cerevisiae mitochondria

Abstract

Two new tetramic acid derivatives, traminines A (1) and B (2), were isolated from a culture broth of Fusarium concentricum FKI-7550 by bioassay-guided fractionation using multidrug-sensitive Saccharomyces cerevisiae 12geneΔ0HSR-iERG6. The chemical structures of 1 and 2 were elucidated by NMR studies. Compounds 1 and 2 inhibited the growth of the multidrug-sensitive yeast strain on non-fermentable medium containing glycerol, but not on fermentable medium containing glucose. These results strongly suggest that they target mitochondrial machineries presiding over ATP production via oxidative phosphorylation. Throughout the assay monitoring overall ADP-uptake/ATP-release in yeast mitochondria, 1 and 2 were shown to inhibit one or more enzymes involving oxidative phosphorylation. Based on biochemical characterization, we found that the interference with oxidative phosphorylation by 1 is attributable to the dual inhibition of complex III and FoF1-ATPase, whereas that by 2 is solely due to the inhibition of complex III.

A Combination Strategy of Multidrug-Sensitive Budding Yeast and Chemical Modifications Enabling to Find a New Overlooked Antifungal Compound, Sakurafusariene, from In-House Fractionated Library

“…High-and lowresolution mass spectra were obtained using an AB Sciex QSTAR Hybrid LC/MS/MS Systems (AB Sciex, Framingham, MA, USA) and JEOL JMS-T100LP (JEOL, Tokyo, Japan). NMR spectra were measured using a Varian XL-400 spectrometer (Agilent Technologies, CA, USA), with 1 H NMR and 13 C NMR at 400 and 100 MHz, respectively, and JEOL JNM-ECA-500 (JEOL, Tokyo, Japan), with 1 H NMR and 13 C NMR obtained at 500 and 125 MHz in CDCl 3 . The chemical shifts are reported in ppm and referenced to CDCl 3 (7.26 ppm) in the 1 H NMR spectra and CDCl 3 (77.16 ppm) in the 13 C NMR.…”

“…The residue was purified by flash column chromatography (Hexane:EtOAc = 15:1) to give the desired product (18 mg, 59.2 μmol, 11%). 1 H NMR (CDCl 3 , 500 MHz) δ 7.28 (1H, qd, J = 1.5, 11.5 Hz), 6.98 (1H, dq, J = 1.5, 7.0 Hz), 6.61 (1H, d, J = 15.0 Hz), 6.51 (1H, dd, J = 11.5, 15.0 Hz), 6.18 (1H, s), 6.03 (1H, s), 3.77 (3H, s), 3.75 (3H, s), 2.06 (3H, d, J = 1.0 Hz), 2.00 (3H, d, J = 1.5 Hz), 1.78 (3H, dd, J = 1.0, 7.0 Hz), 1.71 (3H, d, J = 1.0 Hz); 13 2.6. Preparation Procedure of Allyl Ester Derivative 5.…”

“…Compounds found from the Fusarium sp. FKI-7550 strain; Supplemental figures of the structure elucidation of sakurafusariene (1); 1 H NMR, 13…”

“…To address some of these obstacles, we have reported a screening method for new fungicide candidates using multidrug-sensitive yeast, S. cerevisiae 12geneΔ0HSR-iERG6, , which has identified new natural products. − The Fusarium sp. FKI-7550 strain enabled us to find three characteristic compounds, fusaramin and traminines A and B (Figure S1). We envisioned that Fusarium sp.…”

“…Furthermore, the budding yeast Saccharomyces cerevisiae, a model organism of the fungi, has the resistance to various drugs due to the drug efflux pump, hindering the discovery of new compounds. To address some of these obstacles, we have reported a screening method for new fungicide candidates using multidrug-sensitive yeast, S. cerevisiae 12geneΔ0HSR-iERG6, , which has identified new natural products. − The Fusarium sp. FKI-7550 strain enabled us to find three characteristic compounds, fusaramin and traminines A and B (Figure S1).…”