Tyroscherin and tyroscherin analogs from Pseudallescheria boydii SNB-CN85 isolated from termite Termes cf. hispaniolae

Abstract

Two new tyroscherin derivatives: N-methyl-tyroscherone (2) and tyroscherin N,O-acetonide (3), as well as two known secondary metabolites tyroscherin (1) and pseurotin A (4), were isolated from a solid culture of the termite-borne fungus Pseudallescheria boydii SNB-CN85. The structures were elucidated by spectroscopic analysis and chemical modification. Compound 3 was synthesized from tyroscherin (1) in the free amine form by heating in deuterated acetone, followed by deuterium-proton exchange in MeOH. All compounds were tested for their antimicrobial activities on C. albicans and S. aureus, and 2 and 3 exhibited minimal inhibitory concentrations between 128 and 8 g.mL-1 .

Dereplication, Annotation, and Characterization of 74 Potential Antimicrobial Metabolites from Penicillium Sclerotiorum Using t-SNE Molecular Networks

“…Insect–microorganism interactions have been widely studied within apocrites (bees, wasps, ants), but few studies are related to termite–microorganism interactions outside the trophobiosis [ 5 , 6 , 7 , 8 ]. However, examples of antimicrobial compounds produced by microorganisms associated with termites from French Guiana were previously published in the literature, especially by the research group of D. Stien and V. Eparvier [ 9 , 10 , 11 , 12 ].…”

Antiparasitic Ovalicin Derivatives from Pseudallescheria boydii, a Mutualistic Fungus of French Guiana Termites

“…Previous studies in our group led to the isolation of six fungal strains of the genus Pseudallescheria from three different termite colonies (out of eight nests harvested) [20][21][22]. Our preliminary results suggest that the fungi genus Pseudallescheria may be frequently associated with termites, exchanged between individuals, and spread in the nest.…”

Combining OSMAC, Metabolomic and Genomic Methods on Termite Symbiotic Fungi for the Production and Annotation of Halogenated Azaphilones and Ilicicolins

“…0.7 ppm) (Figure 5). Azaphilones scaffold was identi ed by observation in 13 C NMR of carbon with chemical shifts at δ C 153.2, 159.7 and 184.5 (C-1, C-3 and C-6 respectively) and validated by HMBC correlations of H1/C-3, C-4a, and C-8a, H4/C-3, C-5, C-8, C-8a and nally H18/C-6, C-7 and C-8. In addition, the HMBC correlations of H-9, H-10 with C-3 and H-4 with C-3 allowed to connect the side chain.…”

“…Fraction F6 was puri ed using an isocratic condition of solvent B 80% for 40 min and led to the isolation of the new compound 22 (2.5 mg, t R = 28.6 min). 5-Bromoisorotiorin ( 22): orange amorphous oil; [α] 20 D 330 (c 0.1 g.L -1 , MeOH), UV (MeOH) λmax (ε), 380 (5 800 L.mol -1 .cm -1 ), 422 (6 000 L.mol -1 .cm -1 ), 1 13 RPLC-ESI(+)-MS/MS analysis. Crude extracts of all SNB-CN strains cultivated and extracted as previously described together with fractions from Penicillium sclerotiorum SNB-CN111 were prepared at 1 mg.mL -1 in methanol and ltered on 0.45 µm PTFE membrane.…”

“…In the literature, the research group of V. Eparvier described examples of antimicrobial compounds produced by termite's symbiotic microorganisms [6,10,11,12,13,14,15,16]. Among the studied termiteassociated microorganisms, chlorinated metabolites of ilicicolin and azaphilone families were isolated from Neonectria discophora and Penicillium sclerotiorum fungal strains [14,15,16].…”