title: Isolation and identification of impurities in chlorin e6.
abstract: The tetrapyrrolic compound chlorin e6 is currently used as a pharmaceutical substance for Photolon formulation, which is utilized in photodynamic therapy of various diseases. It was found that chlorin e6 could contain both process- and degradation-related impurities. In order to understand their origin, the most abundant impurities were prepared by liquid extraction, preparative chromatography or chemical synthesis. By means of HPLC-PDA-MS, 1D and 2D NMR spectroscopy, these impurities were identified as chlorin e6 17(4)-ethyl ester, chlorin e4, 15-hydroxyphyllochlorin, rhodochlorin, 15(1)-hydroxymethylrhodochlorin delta-lactone, rhodochlorin-15-oxymethyl delta-lactone, rhodochlorin-15-oxymethyl delta-lactone 17(4)-ethyl ester, 15(1)-hydroxymethylrhodoporphyrin delta-lactone, rhodoporphyrin-15-oxymethyl delta-lactone and purpurin 18. The possible routes of formation of the chlorin derivatives upon the production and storage of chlorin e6 are discussed.
authors.affiliation: Scientific Pharmaceutical Center, RUE Belmedpreparaty, Fabritsius Str. 30, Minsk 220007, Belarus.
authors.forename: H A
authors.initials: HA
authors.lastname: Isakau
authors.affiliation: Scientific Pharmaceutical Center, RUE Belmedpreparaty, Fabritsius Str. 30, Minsk 220007, Belarus.
authors.forename: T V
authors.initials: TV
authors.lastname: Trukhacheva
authors.affiliation: Scientific Pharmaceutical Center, RUE Belmedpreparaty, Fabritsius Str. 30, Minsk 220007, Belarus. Electronic address: nfc@belmedpreparaty.com.
authors.forename: P T
authors.initials: PT
authors.lastname: Petrov
mesh_terms: D002735:Chlorophyllides; D002851:Chromatography, High Pressure Liquid; D004340:Drug Contamination; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure; D011166:Porphyrins / Q000737:chemistry / Q000302:isolation & purification*; D011838:Radiation-Sensitizing Agents / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D002735:Chlorophyllides; D011166:Porphyrins; D011838:Radiation-Sensitizing Agents; C062985:phytochlorin