16α hydroxyestrone

The internal standards (d3-testosterone, d4-cortisol, d9-progesterone, d7-cholesterol, 13c3-androstene-3,17-dione, and 13c3-estrone) were purchased from Cerilliant (Round Rock, TX, USA). L-ascorbic acid, sodium acetate, acetic acid, β-glucosaldosidase/arylsulfatase, ammonium iodide (NH4I), dithioerythritol (DTE), and N-methyl-n-(trimethylsilyl)trifluoroacetamide (MSTFA) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Commercial standards of steroids (dehydroepiandrosterone, testosterone, 11-deoxycorticosterone, cortisone, cortisol, 16α-hydroxyestrone, pregnenolone, 17α-hydroxypregnenolone, epipregnanolone, dihydrotestosterone, 21-hydroxyprogesterone, androsterone, epiandrosterone, corticosterone, estrone, 17β-estradiol, estriol, 16-epiestriol, progesterone, 17α-hydroxyprogesterone, desmosterol, cholesterol, etc.) were purchased from Sigma-Aldrich, J&K Chemical Ltd. (Beijing, China), or Santa Cruz Biotechnology, Inc. (Santa Cruz, CA). Chromatographic pure hexane, methanol, and ethyl acetate were purchased from Merck (Fairfield, OH, USA). The Oasis HLB SPE cartridge was obtained from Waters (1.5 ml, 60 mg; Waters, Milford, MA, USA).

Estrone(E1), 17β-estradiol(E2), estriol(E3), 2-hydroxyestrone(2-OHE1), 2-hydroxyestradiol(2-OHE2), 2-methoxyestrone(2-MeOE1), 2-methoxyestradiol(2-MeOE2), 4-hydroxyestrone(4-OHE1), 4-hydroxyestradiol(4-OHE2), 4-methoxyestrone(4-MeOE1), 4-methoxyestradiol(4-MeOE2), 16α-hydroxyestrone(16α-OHE1), d5-E2, dansyl chloride, Vitamin C, naloxone, naloxone-glucuronide, D-Saccharic acid 1,4-lactone monohydrate and UGPGA were supplied by Sigma-Aldrich (St. Louis, USA) and Steraloids (Rhode, USA).
Tamoxifen was obtained from Aladdin (Shanghai, China). Alamethicin was obtained from J&K Scientific. TRIzol® and PrimeScript RT Reagent Kit were purchased from TaKaRa Bio-technology Co., Ltd. (Beijing, China). Human liver microsomes (HLMs) were acquired from Rild Liver Disease Research Co., Ltd (Shanghai). All analytical solvents were of liquid chromatography (LC) - grade and were obtained from Sigma-Aldrich (St. Louis, USA) or Merck (Darmstadt, Germany).