Two new usnic acid derivatives from the endophytic fungus Mycosphaerella sp.

Abstract

The endophytic fungus Mycosphaerella sp. (UFMGCB2032) was isolated from the healthy leaves of Eugenia bimarginata, a plant from the Brazilian savanna. Two novel usnic acid derivatives, mycousfuranine (1) and mycousnicdiol (2), were isolated from the ethyl acetate extract, and their structure was elucidated by NMR and MS analyses. Compounds 1 and 2 exhibited moderate antifungal activities against Cryptococcus neoformans and Cryptococcus gattii, each with minimum inhibitory concentration values of 50.0 μg/mL and 250.0 μg/mL, respectively.

Biological Activities of Some New Secondary Metabolites Isolated from Endophytic Fungi: A Review Study

“…(UFMGCB2032) was isolated from the healthy leaves of Eugenia bimarginata , a plant from the Brazilian savanna. Two novel usnic acid derivatives, mycousfuranine 368 ( Figure 12 ) and mycousnicdiol 369 ( Figure 12 ), were isolated from the ethyl acetate extract [ 120 ]. Intriguingly, incorporaion of Cu 2+ into the PDB medium of the endophytic fungus, Anteaglonium sp.…”

“…In search for novel antifungal compounds, 368 and 369 were tested against C. neoformans and C. gattii . Compounds 368 and 369 exhibited moderate antifungal activities against Cryptococcus neoformans and Cryptococcus gattii , each with minimum inhibitory concentration values of 50.0 μg/mL and 250.0 μg/mL, respectively [ 120 ].…”

A Pair of Chromone Epimers and an Acetophenone Glucoside from the Mangrove Endophytic Fungus Mycosphaerella sp. L3A1

“…Mycosphaerella , as the largest genus of Ascomycota, is a plant pathogen widely existed in terrestrial plant and marine ecosystem [11–13] . Previous studies of this genus manifested that it could produce various kinds of new natural products with different bioactivities, including usnic acid derivatives with antibacterial [11] or antifungal activities, [14] iron(III) chelator of coprogen‐type siderophore with the function of promoting the biofilm formation, [15] cercosporin with cytotoxic activity, [16] and cytochalasin dimer with α ‐glucosidase inhibitory activity and antioxidant activity, [17] and so on. Our research group had focused on the exploration of new bioactive metabolites from mangrove endophytic fungi collected from the South China Sea in the past two decades [18–21] .…”

Mycousfurans A and B, Antibacterial Usnic Acid Congeners from the Fungus Mycosphaerella sp., Isolated from a Marine Sediment

“…Mycosphaerella species produce secondary metabolites including rosigenin [8], rubellins A and B [9], (−)-mycousnine, and (+)-isomycousnine [10]. Mycousfuranine and mycousnicdiol have also been recently reported to possess antifungal activity [11]. Mycosphaerella species are generally known as foliicolous plant pathogens, isolated from the leaves of plants; however, some species are also found in marine environments.…”