Biologically active metabolites produced by the basidiomycete Quambalaria cyanescens.

Four strains of the fungus Quambalaria cyanescens (Basidiomycota: Microstromatales), were used for the determination of secondary metabolites production and their antimicrobial and biological activities. A new naphthoquinone named quambalarine A, (S)-(+)-3-(5-ethyl-tetrahydrofuran-2-yliden)-5,7,8-trihydroxy-2-oxo-1,4-naphthoquinone (1), together with two known naphthoquinones, 3-hexanoyl-2,5,7,8-tetrahydroxy-1,4-naphthoquinone (named here as quambalarine B, 2) and mompain, 2,5,7,8-tetrahydroxy-1,4-naphthoquinone (3) were isolated. Their structures were determined by single-crystal X-ray diffraction crystallography, NMR and MS spectrometry. Quambalarine A (1) had a broad antifungal and antibacterial activity and is able inhibit growth of human pathogenic fungus Aspergillus fumigatus and fungi co-occurring with Q. cyanescens in bark beetle galleries including insect pathogenic species Beauveria bassiana. Quambalarine B (2) was active against several fungi and mompain mainly against bacteria. The biological activity against human-derived cell lines was selective towards mitochondria (2 and 3); after long-term incubation with 2, mitochondria were undetectable using a mitochondrial probe. A similar effect on mitochondria was observed also for environmental competitors of Q. cyanescens from the genus Geosmithia

Effect of quambalarine B (2) and mompain (3) on the adenocarcinoma cell line HeLa.

<p>0.25% DMSO was used as a solvent and as a control. Upper panels: visualization of mitochondria using MitoTracker Red CMXRos (red), actin cytoskeleton using Phalloidin (green), lysosomes using monoclonal antibody MEM 259 recognizing the lysosomal protein LAMP2 (white) and nuclei with DAPI (blue). Lower panels: simultaneous visualization of mitochondria, lysosomes and nuclei only.</p

Left column: Structural formulas, FTMS data, and physical characteristics of naphthoquinones isolated from submerged culture of <i>Quambalaria cyanescens</i>; right column: X-ray structures, the displacement ellipsoids are drawn on 50% probability level.

<p>Left column: Structural formulas, FTMS data, and physical characteristics of naphthoquinones isolated from submerged culture of <i>Quambalaria cyanescens</i>; right column: X-ray structures, the displacement ellipsoids are drawn on 50% probability level.</p

Proceedings of the 29th National Conference of the Czech Association of Occupational Therapists

Proceedings of the Conferenc