Six Triterpenoid Saponins from Maesa laxiflora

Six new triterpenoid saponins, maelaxins A−F (<BO>1</BO>−<BO>6</BO>), were isolated from a n-BuOH extract of the leaves of Maesa laxiflora. They possess 22-O-angeloyl-camelliagenin A, 16-O-acetyl, 22-O-angeloyl-camelliagenin A, or 22-O-(2Z)-hexenoyl-camelliagenin A as the aglycon. The pentasaccharide moiety linked to C-3 of the aglycon consists of <SCP>d</SCP>-glucuronic acid, <SCP>l</SCP>-rhamnose, <SCP>d</SCP>-glucose, and/or <SCP>d</SCP>-galactose. Their structures were elucidated by extensive NMR experiments including ¹H−¹<BBR RID="np990028sb00001">H (COSY, 2D HOHAHA, NOESY) and ¹H−¹³C (HMQC and HMBC) spectroscopy and chemical evidence.