title: Antitumor agents. 180. Chemical Studies and cytotoxic evaluation of cumingianosides and cumindysoside A, antileukemic triterpene glucosides with a 14,18-cycloapotirucallane skeleton.
abstract: Treatment of cumingianosides and cumindysoside A, which possess a 14,18-cycloapotirucallane skeleton, with p-toluenesulfonic acid in CH2Cl2 yielded new triterpene glucosides. Cumingianoside A (1) gave 10 and 11, along with cumingianoside Q (5). The structures of 10 and 11 were determined on the basis of spectral examination and contained a dammar-13(17)-ene and a 17(R),23(R)-epoxydammarane skeleton, respectively. Cumingianoside C (2) afforded, together with cumingianoside P (6), products 12 and 13, which were similar to 10 and 11, respectively. With a short reaction time at room temperature, cumingianoside E (3) yielded cumingianoside D (4). In contrast, when 3 was treated with p-toluenesulfonic acid in CH2Cl2 overnight at 5 degrees C, it gave two products, 9 and 14. Extensive spectroscopic examination revealed that 9 possessed a dammar-12-ene skeleton, while 14 was a pentacyclic tetranortriterpene glucoside with a novel skeleton. Cumindysoside A (8) gave a product (15) similar to 14. The cytotoxicities of 9-15 were evaluated against a panel of 58 human tumor cell lines. Compounds 11-15 exhibited potent cytotoxicity with log GI50 values ranging from -7.11 to -4.94, especially against leukemia and colon-tumor cell lines.
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: I S
authors.initials: IS
authors.lastname: Chen
authors.forename: H
authors.initials: H
authors.lastname: Katayama
authors.forename: Y
authors.initials: Y
authors.lastname: Ikeshiro
authors.forename: K H
authors.initials: KH
authors.lastname: Lee
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D016339:Spectrometry, Mass, Fast Atom Bombardment; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D006027:Glycosides; D014315:Triterpenes; C109948:cumindysoside A; C109947:cumingianoside A; C104692:cumingianoside Q