Cyclic heptapeptides with metal binding properties isolated from the fungus Cadophora malorumfrom Antarctic soil

DONALLE, GUIDMAR; MARTORELL, MARIA M.; SILLES, GASTÓN ; RUBERTO, LUCAS A.; CABRERA, GABRIELA

Natural Products and Bioprospecting

Springer

Año: 2022

The Antarctic fungus Cadophora malorumproduces previously undescribed cyclic heptapeptides (cadophorin Aand B) containing an anthranilic acid residue. The planar structure of these peptides was determined by high-resolution mass spectrometry combined with extensive 1D and 2D NMR spectroscopy. The absolute confguration of the amino acids was determined by Marfey’s method, with HPLC analysis of FDVA (Nα-(2,4-dinitro-5-fuorphenyl)-l-valinamide) derivatives making use of a PFP column. Remarkably, cadophorin 2possesses both the uncommon d-Ile and d-allo-Ile in its structure. The peptides have metal binding properties as shown by LCMS with post columnaddition of metal salt solutions. These results were supported by DFT calculations.