title: Synthesis and structure verification of the vaccine adjuvant QS-7-Api. Synthetic access to homogeneous Quillaja saponaria immunostimulants.
abstract: QS-7-Api is an exceedingly potent immuno-adjuvant isolated from the bark of Quillaja saponaria. It is significantly less toxic than QS-21, a related saponin that is currently the favored adjuvant in anticancer and antiviral vaccine clinical trials. Tedious isolation/purification protocols and uncertainty in its structural constitution have hindered the clinical development of QS-7. A chemical synthesis of QS-7-Api is described, providing structural verification of the adjuvant. A novel semisynthetic sequence to QS-7-Api has also been established, greatly facilitating access to QS-7 for preclinical and clinical evaluation.
authors.affiliation: Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, USA.
authors.forename: Kai
authors.initials: K
authors.lastname: Deng
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Adams
authors.forename: David Y
authors.initials: DY
authors.lastname: Gin
mesh_terms: D000276:Adjuvants, Immunologic / Q000138:chemical synthesis / Q000737:chemistry*; D002240:Carbohydrate Sequence; D006031:Glycosylation; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D031990:Quillaja / Q000737:chemistry*; D012503:Saponins / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000276:Adjuvants, Immunologic; D009844:Oligosaccharides; D010936:Plant Extracts; C112621:QS 7; D012503:Saponins