Methanol

The reagents were used as received. Griseofulvin was purchased from Tokyo Chemical Industry Co., Ltd. (Tokyo, Japan). The purity of the Griseofulvin was guaranteed to be ≥97.0%. Hydrocortisone, methanol, polyvinylpyrrolidone K30 (PVP K30), buffer components (sodium dihydrogen phosphate dihydrate (NaH₂PO₄⸱2H₂O), sodium hydroxide (NaOH), sodium chloride (NaCl)), heptane, sorbitan monooleate, acetonitrile (MeCN) and trifluoroacetic acid (TFA) were purchased from FUJI FILM Wako Pure Chemical Co. (Osaka, Japan). Hydrocortisone and PVP K30 were Wako special grade. The purity of the Hydrocortisone was guaranteed to be ≥97.0%. The NaH₂PO₄⸱2H₂O, NaOH, NaCl and heptane were guaranteed reagents. The purity of the NaH₂PO₄⸱2H₂O, NaOH, NaCl and heptane was guaranteed to be 99.0–102.0%, ≥97.0%, ≥99.5% and ≥99.0%. The methanol, MeCN and TFA were for high-performance liquid chromatography (HPLC). The purity of the methanol, MeCN and TFA was guaranteed to be ≥99.7%, ≥99.9% and ≥99.8%. Dioctyl sulfosuccinate (AOT) and sodium lauryl sulfate (SLS) were purchased from Sigma–Aldrich (St. Louis, MO, USA). The purity of the AOT and SLS was guaranteed to be ≥97% and ≥98.0%. Gastrointestinal tract (GIT) lipids and the acceptor sink buffer (ASB) were purchased from Pion Inc. (Billerica, MA, USA).

Tyrosinase (from mushrooms, specific activity 1715 U/mg), horseradish peroxidase, Ampliflu^TM Red reagent (1-acetyl-3,7-dihydroxyphenoxazine), L-CySH, SOD (from bovine erythrocytes, specific activity 3000 U/mg), catalase (from bovine liver, 44,000 U/mg), and hexane were purchased from Sigma-Aldrich (St. Louis, MO, USA). Dimethyl sulfoxide, 3,5-di-tert-butyl-1,2-benzoquinone (DBBQ), 2-mercaptoethanol (thioglycol), GSH, NaN₃, formic acid, and methanol (HPLC (High performance liquid chromatography) grade) were purchased from Wako Pure Chemical Industry (Osaka, Japan). H₂O₂ was purchased from Mitsubishi Gas Chemical Company, Ltd. (Tokyo, Japan). Perchloric acid was purchased from Katayama Chemical Industries Co., Ltd. (Osaka, Japan). All other chemicals were of the highest purity commercially available. The highest purity Milli-Q water (Milli-Q Advantage, Merck Millipore Co., Tokyo, Japan) was used throughout this study to avoid contamination with metal ions. Hairs from recessive yellow (e/e), black (a/a), and albino (c/c) mice were obtained from the National Institute of Radiological Sciences, Chiba, Japan. We prepared DHBTCA using a method similar to that reported for the dihydrobenzothiazine derivative of 5SCD [65 (link)] and BZ-AA as described by Di Donato et al. [66 (link)] with some modifications [26 (link)].

Pieces of Japanese cypress (Chamaecyparis obtuse) (Yamani, Co., Ltd., Nagano, Japan) with dimensions of 5.0 mm (longitudinal direction, L) × 20 mm (radial direction, R) × 20 mm (tangential direction, T) were used as wood specimens. The specimens were cut from a larger piece with a transverse section of 20 mm (R) × 20 mm (T). The initial mass of these specimens was ~0.7 g. Methanol, propionic anhydride (PA), trifluoroacetic anhydride (TFAA), propionic acid, 4-dimethylaminopyridine (DMAP), N-methyl pyroridone, sodium hydrogen sulfate, and sulfuric acid (SA) were purchased from FUJIFILM Wako Pure Chemical Corp. (Osaka, Japan) and utilized as obtained.

GGA was prepared by Kuraray Co. (Okayama, Japan) and Kowa Pharmaceutical (Tokyo, Japan). GGOH was provided by Eisai Foods (99% pure; Tokyo, Japan). Acetonitrile (LC/MS grade), ethanol, dimethyl sulfoxide (DMSO), ABT, BG and TCP were purchased from Sigma-Aldrich (St. Louis, MO, USA). Methanol was purchased from Wako Pure Chemical Industries (Osaka, Japan). Chloroform was obtained from Kanto Chemical Co. (Tokyo, Japan). rhCYP3A4 was purchased from BioVision (Milpitas, CA, USA). All chemicals other than those stated above were of reagent grade.

The volatile standards used in this study are shown in Additional File 4: Table S1. First, 2,4-dichloroaniline (99.5% purity) was purchased from Tokyo Chemical Industry Co., Ltd. (Tokyo, Japan) for the reagents. However, while n-heptyl β-D-glucopyranoside (98% purity) was purchased from Sigma-Aldrich, Inc. (St. Louis, MO, USA), dichloromethane (99.5% purity), liquid chromatography-mass spectrometry-grade methanol, citric acid, sodium phosphates, sodium fluoride (NaF), ascorbic acid, sodium hydroxide (NaOH) and 3-octanol (97% purity) were obtained from Wako Co. Ltd. (Osaka, Japan).

Ethanol (Wako), acetonitrile (Wako), mEthanol (Wako), sulfuric acid (Wako), acetone (Wako), trifluoroacetate (Tokyo Chemical Industry), dimethyl sulfoxide (Wako), MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide), LPS and Griess reagent were all purchased from Sigma (St. Louis, MO, USA). An ELx 800 Universal Microplate Reader (BIO-TEK), VD-250R Freeze Dryer (TAITEC), US-105 Sonicator (SND), 5420 Centrifuge (IMOTO), R-300 Rotavapor (BUCHI), V-300 Vacuum Pump (BUCHI), High Performance Flash Chromatography (HPFC) system (Biotage AB), Medium Pressure Liquid Chromatography (MPLC) system (EPCLC, Yamazen), Preparative High Performance Liquid Chromatography (PHPLC) system (EPCLC, Yamazen), 1220 Infinity LC (Agilent Technologies), NMR spectrometer (Bruker DRX-600; Bruker Daltonics, Billerica MA, USA), Quadrupole time-of-flight (qTOF) mass spectrometer (Agilent Technologies, USA) and JASCO DIP-370 polarimeter (JASCO, Tokyo, Japan) were used.