GLYCOSYL COMPOSITIONS AND STRUCTURAL CHARACTERISTICS OF THE POTENTIALIMMUNO-ADJUVANT ACTIVE SAPONINS IN THE QUILLAJA-SAPONARIA MOLINA EXTRACT QUIL-A

Fifty saponin components of Quil A, a commercially available extract f rom the bark of the South American tree Quillaja saponaria Molina, wer e partially structurally characterised. The molecular weights were det ermined by fast-atom bombardment mass spectrometry. The glycosyl and e lemental composition of all the saponins was determined by applying ou r recently developed method, monomer mapping, consisting of a computer program and accurate mass measurements. Support for the presumed iden tity of the aglycone, i.e. quillaic acid, was found in the accurate ma ss determination,H-1 NMR measurement and chemical reactions. The sapon in composition of Quil A was shown to consist of pairs. Within the 3-O bound glycosyl moiety of a pair there was a structural difference: a pentose and rhamnose were interchanged. Structural differences between different pairs were located in the 28-O bound glycosyl moiety. A str uctural element, unknown to date and of which the elemental compositio n was deduced to be C8H12O5, was found in the 28-O bound glycosyl moie ty of several saponins.