A Novel Clerodane Ascorbate Adduct From Brachyglottis bidwillii

Abstract

Investigation of the antibacterial activity of extracts from Brachyglottis bidwillii var. bidwillii revealed the major activity to be associated with four compounds (1)-(4). Two of these compounds are novel diterpene-ascorbate adducts, 5-O-acetyl-2-C-(cleroda-3,13-dien-15-yl)-β-L-xylo-3-hexulofuranosonic acid γ- lactone (1) and the 5-hydroxy equivalent (2). The structures of (1) and (2) were determined from X-ray and spectroscopic data. The two other compounds are known diterpenes labda-7,13-dien-15-ol (3) and kolavenol (4).