title: Antitumor agents, 157. Absolute structures of cumingianosides A-F, antileukemic triterpene glucosides, and structures of the hydrolysates of cumingianoside A.
abstract: The stereostructures of cumingianosides A-F, a series of triterpene glucosides with a 14,18-cycloapoeuphane skeleton, have been established by X-ray crystallographic analysis on an aglycone [1c] the acid hydrolysate of cumingianoside A [1], which is a potent cytotoxic triterpene against MOLT-4 human leukemia cells with an EC50 value of < 0.00625 microM. The 14,18-cyclopropane ring in cumingianoside A [1] was opened under acidic conditions in two different directions to give compounds with an apoeuphane skeleton and a dammarane skeleton. Furthermore, it was found that subsequent hydrolysis yielded not only an aglycone with an apoeuphane skeleton [1c] but also an apo-rearrangement product [1d].
authors.affiliation: Natural Products Laboratory, School of Pharmacy, University of North Carolina, Chapel Hill 27599, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Kashiwada
authors.forename: T
authors.initials: T
authors.lastname: Fujioka
authors.forename: K
authors.initials: K
authors.lastname: Mihashi
authors.forename: N
authors.initials: N
authors.lastname: Marubayashi
authors.forename: K
authors.initials: K
authors.lastname: Mizuki
authors.forename: I S
authors.initials: IS
authors.lastname: Chen
authors.forename: K H
authors.initials: KH
authors.lastname: Lee
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D018360:Crystallography, X-Ray; D005960:Glucosides / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D006801:Humans; D006868:Hydrolysis; D007942:Leukemia, Experimental / Q000188:drug therapy*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D018515:Plant Leaves / Q000737:chemistry; D014315:Triterpenes / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D005960:Glucosides; D014315:Triterpenes