title: Structure-activity studies of uptake and phototoxicity with heavy-chalcogen analogues of tetramethylrosamine in vitro in chemosensitive and multidrug-resistant cells.
abstract: Several thio and seleno analogues of tetramethylrosamine (TMR) were prepared. Thio derivatives of TMR have absorption maxima near 570 nm, while seleno derivatives of TMR have absorption maxima near 580 nm. The 3- or 4-N,N-dimethylaminophenyl substituent in the 9-position greatly increases internal conversion, which lowers quantum yields for fluorescence and the generation of singlet oxygen. Thio and seleno analogues of TMR are effective photosensitizers against chemosensitive AUXB1 cells in vitro and against multidrug-resistant CR1R12 cells in vitro, which have been treated with verapamil. The CR1R12 cells accumulated significantly lower concentrations of the photosensitizers relative to the AUXB1 cells presumably due to the expression of P-glycoprotein (Pgp) in the CR1R12 cells. Following treatment with 5 x 10(-5) M verapamil, the uptake in CR1R12 cells of several fluorescent thio analogues of TMR is comparable to that observed for the chemosensitive AUXB1 cells.
authors.affiliation: Department of Biochemistry and Biophysics, University of Rochester Medical Center, NY 14641, USA.
authors.forename: Scott L
authors.initials: SL
authors.lastname: Gibson
authors.forename: Jason J
authors.initials: JJ
authors.lastname: Holt
authors.forename: Mao
authors.initials: M
authors.lastname: Ye
authors.forename: David J
authors.initials: DJ
authors.lastname: Donnelly
authors.forename: Tymish Y
authors.initials: TY
authors.lastname: Ohulchanskyy
authors.forename: Youngjae
authors.initials: Y
authors.lastname: You
authors.forename: Michael R
authors.initials: MR
authors.lastname: Detty
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D018011:Chalcogens / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology* / Q000633:toxicity; D006224:Cricetinae; D018432:Drug Resistance, Multiple; D006575:Heterocyclic Compounds, 3-Ring / Q000737:chemistry*; D015394:Molecular Structure; D017319:Photosensitizing Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology* / Q000633:toxicity; D012235:Rhodamines; D013329:Structure-Activity Relationship
chemical_list: D018011:Chalcogens; D006575:Heterocyclic Compounds, 3-Ring; D017319:Photosensitizing Agents; D012235:Rhodamines; C412715:tetramethylrosamine