Uncommon Chlorinated Xanthone and Other Antibacterial Compounds from the Lichen Cladonia incrassata

Amandine Dieu (1) , Marion Millot (1) , Yves Champavier (2) , Lengo Angèle Mambu (1) , Vincent Chaleix (1) , Vincent Sol (1) , Vincent Gloaguen (1)

1 LCSN - Laboratoire de Chimie des Substances Naturelles
2 RMN - Service Commun de Résonance Magnétique Nucléaire

Bioassay-guided fractionation of an extract of the lichen Cladonia incrassata against Staphylococcus aureus led to a novel compound, 1,5-dihydroxy-2,4,6-trichloro-7-methylxanthone (1), along with six known compounds: (−)-usnic acid (2), didymic acid (3), condidymic acid (4), squamatic acid (5), thamnolic acid (6), and prasinic acid (7). Didymic, condidymic, and prasinic acids were isolated for the first time from C. incrassata. Didymic, condidymic, and (−)-usnic acids were active against S. aureus (a minimum inhibitory concentration of 7.5 µg/mL).

Mots clés: xanthone; Cladonia incrassata; Cladionaceae; antibacterial; Staphylococcus aureus; structure elucidation

Domaines: Chimie thérapeutique

Amandine Dieu, Marion Millot, Yves Champavier, Lengo Angèle Mambu, Vincent Chaleix, et al.. Uncommon Chlorinated Xanthone and Other Antibacterial Compounds from the Lichen Cladonia incrassata. Planta Medica, 2014, 80, pp.931-935. ⟨10.1055/s-0034-1382827⟩. ⟨hal-01058414⟩