title: Identification and quantification of bleomycin in serum and tumor tissue by liquid chromatography coupled to high resolution mass spectrometry.
abstract: Bleomycin is a cytotoxic antibiotic available as a compost of structurally strongly related glycopeptides, which is in vivo found chelated with several metals. Its pharmacotherapy has merely been based on experimental dose - response data, whereas its biodistribution and pharmacokinetics remain fundamentally unknown. This is reasoned by an absence of a specific and sensitive mass spectrometry-based analytical method for its determination in biological tissues. We herein reveal the results of our study on the mass spectrometric behavior of two main bleomycin fractions A2 and B2, including their metal complexes, particularly the predominant copper chelates. In the electrospray ion source bleomycin forms double charged species, where for the metal-free fraction A2 and its copper complex m/z 707.76 and m/z 707.21 are seen, respectively. Hence, the second isotopic ion of the chelate (m/z 707.71) nearly coincides with the first isotopic ion of the metal-free fraction. This phenomenon can only be followed by high-resolution mass spectrometry, and is considered the plausible reason, why the attempts to determine bleomycin with mass spectrometry have been so scarce. The presented paper further describes a sensitive and selective liquid chromatography - mass spectrometry analytical method for determination of bleomycin in serum and tumor tissues. This newly developed method was employed for bleomycin pharmacokinetic studies in serum and tumors of laboratory animals. Additionally, the method was employed for determination of bleomycin pharmacokinetic parameters in elderly patients in order to determine the effective therapeutic window of electrochemotherapy with bleomycin.
authors: Department of Environmental Sciences, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia. Electronic address: tina.kosjek@ijs.si.
authors: Tina
authors: T
authors: Kosjek
authors: Department of Environmental Sciences, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia.
authors: Anja
authors: A
authors: Krajnc
authors: Department of Environmental Sciences, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia.
authors: Tjasa
authors: T
authors: Gornik
authors: Department of Environmental Sciences, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia.
authors: Dusan
authors: D
authors: Zigon
authors: Department of Otorhinolaryngology and Cervicofacial Surgery, University Medical Centre Ljubljana, Zaloska 2, Ljubljana SI-1000, Slovenia.
authors: Ales
authors: A
authors: Groselj
authors: Department of Experimental Oncology, Institute of Oncology Ljubljana, Zaloska 2, SI-1000 Ljubljana, Slovenia.
authors: Gregor
authors: G
authors: Sersa
authors: Department of Experimental Oncology, Institute of Oncology Ljubljana, Zaloska 2, SI-1000 Ljubljana, Slovenia.
authors: Maja
authors: M
authors: Cemazar
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000032:analysis* / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics; D001761:Bleomycin / Q000032:analysis* / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics; D002853:Chromatography, Liquid; D056831:Coordination Complexes / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D005260:Female; D006801:Humans; D008810:Mice, Inbred C57BL; D009369:Neoplasms / Q000737:chemistry* / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D000903:Antibiotics, Antineoplastic; D056831:Coordination Complexes; D001761:Bleomycin; D003300:Copper
keywords: Bleomycin; Copper complex; High-resolution mass spectrometry; Liquid chromatography; Serum; Tumor