TY - JOUR

T1 - Bioactive Ascochlorin Analogues from the Marine-Derived Fungus Stilbella fimetaria

AU - Subko, Karolina

AU - Kildgaard, Sara

AU - Vicente, Francisca

AU - Reyes, Fernando

AU - Genilloud, Olga

AU - Larsen, Thomas O.

PY - 2021

Y1 - 2021

N2 - The marine-derived fungus Stilbella fimetaria is a chemically talented fungus producing several classes of bioactive metabolites, including meroterpenoids of the ascochlorin family. The targeted dereplication of fungal extracts by UHPLC-DAD-QTOF-MS revealed the presence of several new along with multiple known ascochlorin analogues (19-22). Their structures and relative configuration were characterized by 1D and 2D NMR. Further targeted dereplication based on a novel 1,4-benzoquinone sesquiterpene derivative, fimetarin A (22), resulted in the identification of three additional fimetarin analogues, fimetarins B-D (23-25), with their tentative structures proposed from detailed MS/HRMS analysis. In total, four new and eight known ascochlorin/fimetarin analogues were tested for their antimicrobial activity, identifying the analogues with a 5-chloroorcylaldehyde moiety to be more active than the benzoquinone analogue. Additionally, the presence of two conjugated double bonds at C-2'/C-3' and C-4'/C-5' were found to be essential for the observed antifungal activity, whereas the single, untailored bonds at C-4'/C-5' and C-8'/C-9' were suggested to be necessary for the observed antibacterial activity.

AB - The marine-derived fungus Stilbella fimetaria is a chemically talented fungus producing several classes of bioactive metabolites, including meroterpenoids of the ascochlorin family. The targeted dereplication of fungal extracts by UHPLC-DAD-QTOF-MS revealed the presence of several new along with multiple known ascochlorin analogues (19-22). Their structures and relative configuration were characterized by 1D and 2D NMR. Further targeted dereplication based on a novel 1,4-benzoquinone sesquiterpene derivative, fimetarin A (22), resulted in the identification of three additional fimetarin analogues, fimetarins B-D (23-25), with their tentative structures proposed from detailed MS/HRMS analysis. In total, four new and eight known ascochlorin/fimetarin analogues were tested for their antimicrobial activity, identifying the analogues with a 5-chloroorcylaldehyde moiety to be more active than the benzoquinone analogue. Additionally, the presence of two conjugated double bonds at C-2'/C-3' and C-4'/C-5' were found to be essential for the observed antifungal activity, whereas the single, untailored bonds at C-4'/C-5' and C-8'/C-9' were suggested to be necessary for the observed antibacterial activity.

KW - ascochlorin

KW - bioactivity

KW - dereplication

KW - meroterpenoids

KW - MS/HRMS

U2 - 10.3390/md19020046

DO - 10.3390/md19020046

M3 - Journal article

C2 - 33498522

AN - SCOPUS:85100511019

VL - 19

JO - Marine Drugs

JF - Marine Drugs

SN - 1660-3397

IS - 2

M1 - 46

ER -