title: Identification of estrogenic/anti-estrogenic compounds in diesel exhaust particulate extract.
abstract: Diesel exhaust particulate extract (DEPE) was obtained from diesel exhaust particulates with Soxhlet extraction using dichloromethane. After separating DEPE into 11 fractions by liquid-liquid extraction, the neutral fraction (N) showed anti-estrogenic activity and the weak acid (phenol) fraction (WA(P)) showed estrogenic and anti-estrogenic activities by a yeast two-hybrid assay system expressing human estrogen receptor alpha. Both fractions were thoroughly fractionated by silica gel column chromatography and reversed-phase HPLC. In the WA(P) fraction, 3-methyl-4-nitrophenol and 2,6-dimethyl-4-nitrophenol were identified by LC-MS/MS as estrogenic compounds. This is the first study to identify 2,6-dimethyl-4-nitrophenol in DEPE and the first study to show that it is an estrogenic compound. In the N fraction, 1-hydroxypyrene was also identified by LC-MS/MS as an anti-estrogenic compound.
authors.affiliation: Graduate School of Natural Science and Technology/Faculty of Pharmaceutical Sciences, Kanazawa University, Kakuma-machi, Kanazawa, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Noguchi
authors.forename: Akira
authors.initials: A
authors.lastname: Toriba
authors.forename: Sang Woon
authors.initials: SW
authors.lastname: Chung
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Kizu
authors.forename: Kazuichi
authors.initials: K
authors.lastname: Hayakawa
mesh_terms: D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry; D005591:Chemical Fractionation / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003408:Cresols / Q000378:metabolism* / Q000506:poisoning; D052244:Endocrine Disruptors / Q000737:chemistry / Q000378:metabolism; D004784:Environmental Monitoring / Q000379:methods; D004965:Estrogen Antagonists / Q000032:analysis* / Q000737:chemistry; D004967:Estrogens / Q000032:analysis* / Q000737:chemistry; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D009596:Nitrophenols / Q000378:metabolism* / Q000506:poisoning; D012822:Silicon Dioxide / Q000737:chemistry; D013048:Specimen Handling; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D020798:Two-Hybrid System Techniques; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D003408:Cresols; D052244:Endocrine Disruptors; D004965:Estrogen Antagonists; D004967:Estrogens; D009596:Nitrophenols; D001335:Vehicle Emissions; C008636:4-nitro-3-cresol; D012822:Silicon Dioxide