Absolute configuration of (-)-gambogic acid, an antitumor agent.
(-)-Gambogic acid (1), a biologically active "caged xanthone" from gamboge, the dried resin of Garcinia hanburyi, is of interest as a potential anticancer agent. The planar structure of (-)-gambogic acid has been determined previously by analysis of its detailed NMR data and confirmed by single-crystal X-ray diffraction, with the absolute configuration at C-13 deduced as R through a series of chemical degradations. Using (-)-morellic acid (2), an analogue of (-)-gambogic acid, as a model compound, the 5R, 7S, 10aS, 13R, 27S absolute configuration of (-)-gambogic acid was determined for the first time by comparison of physical and spectroscopic data, especially experimental and calculated electronic circular dichroism.
Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210, United States.
Yulin
Y
Ren
Chunhua
C
Yuan
Hee-byung
HB
Chai
Yuanqing
Y
Ding
Xing-Cong
XC
Li
Daneel
D
Ferreira
A Douglas
AD
Kinghorn
D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D004354:Drug Screening Assays, Antitumor; D029760:Garcinia / Q000737:chemistry*; D019073:HT29 Cells; D006801:Humans; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D012116:Resins, Plant / Q000737:chemistry*; D013237:Stereoisomerism; D044004:Xanthones / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*
D000972:Antineoplastic Agents, Phytogenic; D012116:Resins, Plant; D044004:Xanthones; C558352:morellic acid; C052659:gambogic acid