Triterpenoid saponins from Lippia alba (Mill.) N. E. Brown

Abstract

Two saponins were isolated from the leaves of Lippia alba. Their structures were established using one- and two-dimensional NMR spectroscopy and mass spectrometry. These new compounds were elucidated as 3-Ο-β-D- glucopyranosyl-28-Ο-(α-L-rhamnopyranosyl-(1→3) -β-Dxylopyranosyl-( 1→4)-α-L-rhamnopyranosyl-(1→2)-α- L-arabinopyranosyl)-16α, 23-dihydroxy-olean- 12-en-28-oic acid, named as Lippiasaponin I (2) and as 3-Ο-β-D-glucopyranosyl-28-Ο- (α-L-rhamnopyranosyl-(1→3)-β-D-xylopyranosyl-(1→4) -α-L-rhamnopyranosyl-(1→3)-α-Larabinopyranosyl)- 16α, 23-dihydroxy-olean-12-en-28-oic acid, named Lippiasaponin II (3).Das folhas de Lippia alba foram isoladas duas saponinas. As estruturas destas saponinas foram estabelecidas empregando métodos espectroscópicos, principalmente RMN mono e bi-dimensional e espectrometria de massas. Estes novos compostos foram caracterizados como ácido 3-O-β-D-glucopiranosil-28-O-(α-L-rhamnopiranosil-(1→3)-β-D-xilopiranosil-(1→4)-α-L-rhamnopiranosil-(1→2)-α-L-arabinopiranosil)-16α,23-di-hidróxi-olean-12-en-28-óico, designada Lippiasaponina I (2) e como ácido 3-O-β-D-glucopiranosil-28-O-(α-L-rhamnopiranosil-(1→3)-β-D-xilopiranosil-(1→4)-α-L-rhamnopiranosil-(1→3)-α-L-arabinopiranosil)-16α,23-di-hidróxi-olean-12-en-28-óico, designada Lippiasaponina II (3).