Two New Retigerane-Type Sesterterpenoids from the Lichen Leprocaulon microscopicum

Marion Millot (1) , Marie Martin-De-Lassalle (1) , Marylene Chollet-Krugler (2) , Yves Champavier (3) , Lengo Angèle Mambu (1) , José-Albert Chulia (1) , Marie-Aleth Lacaille-Dubois (4)

1 LCSN - Laboratoire de Chimie des Substances Naturelles
2 ISCR - Institut des Sciences Chimiques de Rennes
3 RMN - Service Commun de Résonance Magnétique Nucléaire
4 FDE - Fonctions et dysfonctions épithéliales - UFC (EA 4267)

Two new sesterterpenes, 1 and 2, have been isolated from the lichen Leprocaulon microscopicum. In addition to classic chromatographic methods, a liquid-liquid chromatography technique, namely centrifugal partition chromatography (CPC) was applied for the purification of compound 2. The structures were determined by analyses of mass spectrometry and 1D- and 2D-NMR data. The relative configuration of the isolated compounds was assigned on the basis of 2D-NOESY experiments. The two compounds possess a rare pentacyclic carbon skeleton typical for lichen metabolism, and quite unusual in the vegetal kingdom.

Keywords: Leprocaulon microscopicum; Centrifugal partition chromatography; Sesterterpenes; Retigeranes; Lichens

Domains: Chemical Sciences

Marion Millot, Marie Martin-De-Lassalle, Marylene Chollet-Krugler, Yves Champavier, Lengo Angèle Mambu, et al.. Two New Retigerane-Type Sesterterpenoids from the Lichen Leprocaulon microscopicum. Helvetica Chimica Acta, 2016, 99 (2), pp.169--173. ⟨10.1002/hlca.201500225⟩. ⟨hal-01274108⟩