title: DNA polymerase beta inhibitors from Tetracera boiviniana.
abstract: Bioassay-guided fractionation of an active methyl ethyl ketone extract of Tetracera boiviniana, using a sensitive assay to monitor DNA polymerase beta inhibition, resulted in the isolation of three known triterpenoids, betulinic acid (1), 3-cis-p-coumaroyl maslinic acid (2), and 3-trans-p-coumaroyl maslinic acid (3). Compounds 1-3 inhibited DNA polymerase beta with IC50 values of 14, 15, and 4.2 microM in the presence of bovine serum albumin (BSA) and 6.5, 7.5, and 2.0 microM in the absence of BSA, respectively. Further, compounds 1-3 potentiated the effects of bleomycin in cultured P-388D1 cells.
authors.affiliation: Department of Chemistry, University of Virginia, Charlottesville 22901, USA.
authors.forename: J
authors.initials: J
authors.lastname: Ma
authors.forename: S R
authors.initials: SR
authors.lastname: Starck
authors.forename: S M
authors.initials: SM
authors.lastname: Hecht
mesh_terms: D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D001761:Bleomycin / Q000494:pharmacology; D016466:CHO Cells; D002417:Cattle; D002478:Cells, Cultured; D006224:Cricetinae; D004249:DNA Damage; D019951:DNA Polymerase beta / Q000037:antagonists & inhibitors*; D004357:Drug Synergism; D004791:Enzyme Inhibitors / Q000302:isolation & purification*; D014197:Trees / Q000737:chemistry*; D014315:Triterpenes / Q000302:isolation & purification*
chemical_list: D000964:Antimetabolites, Antineoplastic; D004791:Enzyme Inhibitors; D014315:Triterpenes; D001761:Bleomycin; D019951:DNA Polymerase beta