The structure of the active compound was determined as chlorogenic acid, C16H18O9, melting level 205?206 8C, aD 33.25. Its identification was established by comparing its physical data as well as its infra-red, nuclear magnetic resonance, PFI-1 concentration, and mass spectral data with those of a geniune sample. Antibodies were purchased from the following suppliers: Antibodies to d Abl, Bax, cIAP1, Bcl XL, Bcl 2, phospho STAT5, phospho JNK, phospho p38, actin, SMAC, Bad, Bim, Bid, Mcl 1, survivin, XIAP, DR4, DR5, JNK2 and p38 were purchased from Santa Cruz Biotechnology. Antibody to DR5 was also obtained from eBioscience. Antibodies to poly ADP ribose polymerase, cytochrome c, caspase 3, caspase 9, TNFR1 and TNFR2 were purchased from BD Biosciences. Antibodies to phospho c Abl, caspase 8, cleaved caspase 8 and phospho CrkL were procured from Cell Signaling Technology. D acetyl M cysteine, JNK specific chemical, tetrachloro tetraethylbenzimidazolylcarbocyanineiodide, dichlorodihydrofluorescein diacetate, dihydroethidium, Z VAD FMK, Z IETD FMK and LEHD CHO were from Calbiochem. Polyethylene glycerin conjugated catalase was bought from Sigma?Aldrich. Bcr Abl cell lines K562, KU812 and KCL 22 and Bcr Abl cell lines THP 1, U937 and MOLT 4 were cultured in RPMI 1640 medium containing one hundred thousand fetal bovine serum and 100 U/ml penicillin?streptomycin. Fresh peripheral blood samples from three CML patients and two healthier donors were collected and mononuclear cells were separated by HISTOPAQUE density gradient centrifugation. All experiments with human blood were performed under an approved institutional Human Ethics Committee Organism project. Informed consent was provided based on the Declaration of Helsinki. Cells in triplicate were incubated in 0. 2 ml RPMI 1640?? Ten percent fetal bovine serum containing different concentrations of Chl in the absence and presence of NAC or specific inhibitors of different caspases. Cell viability was based on the Trypan blue exclusion assay. Stability of key CML cells was determined in the exact same way except that recombinant human granulocyte macrophage colony stimulating factor was included. To judge the function of ROS in Chl mediated killing of Bcr Abl cells in vivo, K562 xenografts were developed in nude mice as reported. Chl was administered once each day for 15 days andNAC wasadministered on different days via intra peritoneal route. Tumefaction natural product libraries volumes were checked and after 15 days of therapy, animals were sacrificed and pictures of the dissected tumors were taken during postmortem with Olympus CAMEDIA D 4000 Zoom digicam. Animal studies were performed under an approved institutional Animal Care and Use Committee process. Cells seeded at a density of just one. 5 105 cells/ml were possibly pretreated with NAC or left alone for 1 h followed closely by incubation with Chl at different levels for 24 h.