Ammonium carbonate

As protease inhibitors, EDTA-2Na (purity: >99.5%) and PMSF (purity: >98.5%), were purchased from Dojindo Laboratories (Kumamoto, Japan) and Sigma-Aldrich Japan (Tokyo, Japan), respectively. Acetonitrile (ACN, LC/MS grade, purity: 99.8%), methanol (MeOH, LC/MS grade, purity: 99.7%), ethanol (EtOH, special grade, purity: 99.5%), formic acid (FA, LC/MS grade, purity: 99.5%), acetic acid (AcOH, LC/MS grade, purity: 99.5%), trifluoroacetic acid (TFA, special grade, purity: 98.0%), ammonium carbonate (special grade), and 28% ammonia solution (NH₄OH, special grade) were purchased from Wako Pure Chemical Industries, Ltd. (Osaka, Japan). Water used for the preparation of all the solutions was purified using a Milli-Q apparatus (Millipore, Billerica, MA, USA); LC/MS analysis used ultrapure water from Wako. The mycotoxins (ochratoxin A, fumonisin B1, zearalenone, deoxynivalenol, patulin) were purchased from Sigma (St. Louis, MO, USA). Drugs with amide, ester, and sulfonamide bonds and amino acid-containing compounds were obtained from the following companies: Aldrich and Sigma Japan (Tokyo, Japan), Nacalai Tesque (Kyoto, Japan), Tokyo Chemical Industry (Tokyo, Japan), and Wako Pure Chemical Industries, Ltd. (Osaka, Japan).

Chemical compounds and kits used in the present study were obtained as follows: ammonium carbonate, saponin, and buffer solutions from Wako Chemical (Osaka, Japan); dinasore, bafilomycin A1, rapamycin, and trimethylamine solution from Sigma Aldrich (St. Louis, MO); trimethylamine hydrochloride from TCI (Tokyo, Japan); pHrodo^TMRed AM intracellular pH indicator and chloroquine from Life Technologies (Carlsbad, CA); BCA protein assay kit, cytochalasin D, and nocodazole from Thermo (Waltham, MA); WST-8 Cell Counting kit from Dojindo (Osaka, Japan).

1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD), 1,1,3,3-tetramethylguanidine (TMG), triethylamine (Et₃N) and ammonium carbamate, were purchased from Tokyo Chemical Industry Co., Ltd. 4-dimethylaminopyridine (DMAP), 1,4-diazabicyclo[2.2.2]octane (DABCO), ammonium carbonate, ammonium bicarbonate, urea were purchased from FUJIFILM Wako Pure Chemical Corporation. 1,8-bis(dimethylamino)naphthalene (proton sponge) was purchased from Sigma-Aldrich Japan. All solvents used were of anhydrous grade, and all chemicals were used as received without further purification.