P aminobenzoic acid

Bovine serum albumin (BSA), ammonium sulfate, p-amino benzoic acid (PABA), p-nitro phenyl acetate (PNPA), trizma base (tris), iodo acetic acid, hexamethonium bromide, decamethonium bromide and protein estimation kit (Bradford Method) were obtained from Sigma. Phenyl methyl sulfonyl fluoride (USB, Switzerland) and DTT (SRL, India). All other chemicals and reagents were of analytical grade (Merck, India), unless or otherwise mentioned.

Aryloximes were prepared according to the reported method in the literature [33 (link)]. Arylaldehdyes, hydroxylamine hydrochloride, sodium borohydride, p-aminobenzoic acid, N–N’-dicyclohexylcarbodiimide (DCC), (3-aminopropyl) triethoxysilane (APTES), selenium element, and common reagents were obtained from Sigma-Aldrich company and used as received. All the solvents were obtained from Amertatco and used without further purification.
The procedure for steps of the synthesis of catalyst SBA-15-Se)₂.

Indomethacin, furosemide and p-aminobenzoic acid were purchased from Sigma Aldrich (St. Louis, MO, USA). Saccharin was acquired from Acros Organics (Morris, NJ, USA). The solvents were obtained from POCH (Polish Chemical Reagents, Gliwice, Poland). The purity of substances was ≥98%, the purity of solvent ≥99.8%.

The substances 1-Methylhistidine, adenine, adenosine, arginine, azelaic acid, chenodeoxycholic acid, cholic acid, citrulline, cortisol, cortisone, creatinine, deoxycholic acid, glutaric acid, glycocholic acid, hippuric acid, inosine, isoleucine, leucine, l-pyroglutamic acid, methionine, methylmalonic acid, mevalonolactone, N,N-dimethylglycine, nicotinic acid, p-aminobenzoic acid, phenylalanine, proline, raffinose, riboflavin, taurine, taurocholic acid, tryptophan, and uracil were purchased from Sigma-Aldrich (Buchs, Switzerland). Deuterated and heavy-labeled internal standards (IS) adenosine ribose-D1, arginine-13C6, caffeine 3-methyl-13C, carnitine trimethyl-D9, creatinine N-methyl-D3, deoxycholic acid-D4, D-fructose 13C, glycine-13C2, glycocholic acid-D4, hippuric acid 15N, kynurenine-D4, leucine-D10, lysine-D4, phenylalanine-D1, proline 15N, serine-D3, tryptophan-D5 and uric acid-15N2 were purchased from Cambridge Isotope Laboratories (Cambridge, MA, USA), and were delivered by ReseaChem Life Science (Burgdorf, Switzerland) or Sigma-Aldrich (Buchs, Switzerland). Water, acetonitrile (ACN), methanol (MeOH) of HPLC grade were obtained from Fluka (Buchs, Switzerland). All other chemicals used were from Merck (Zug, Switzerland) and were of the highest grade available.

EGCG, (-)-catechin gallate, gallic acid, gallocatechin, (-)-epigallocatechin, Fe₄(P₂O₇)₃, vitamin K (Yuanyue Biology, Shanghai, China); KH₂PO₄, Na₂HPO₄, NH₄Cl, NaCl, MgCl₂.6H₂O, CaCl₂, NaHCO₃, Na₂S.7–9H₂O, FeCl₂, H₃BO₄, ZnCl₂, CuCl₂, MnCl₂, CoCl₂, NiCl₂, HCl, Na₂SeO₃, Na₂WO₄, Na₂MoO₄, NaOH and starch (Tianjin Fengchuan Chemical Reagent Technologies Co., Ltd, Tianjin, China); hog gastric mucin (Type III), biotin, niacin, pyridoxine, riboflavin, thiamine, cyanocobalamin, p-aminobenzoic acid, and pantothenic acid, hydroxyhydroquinone, 3,4-dihydroxybenzaldehyde, resazurin (Sigma, Shanghai, China); peptone, yeast extract, glucose, sodium pyruvate, arginine, sodium succinate, L-cysteine HCl, haemin, sodium thioglycolate, Cellobiose (Meilunbio, Dalian, China); paraformaldehyde, SDS, formamide (Biotopped, Bejing, China) were all of analytical grade, with mass fractions ≥ 98%.

Quinocetone (QCT), OLA, MEQ, CBX, cyadox (CYX), DMEQ, desoxyolaquindox (DOLA), desoxyquinocatone (DQCT), desoxycarbadox (DCBX), desoxycyadox (DCYX), N1-desoxycyadox (N1-DCYX), N4-desoxycyadox (N4-DCYX), MQCA, and QCA were purchased from Sigma (USA). N-acetylsulfanilyl chloride, p-aminobenzoic acid (PABA), carboxymethyl hydroxylamine (AOAA), N-hydroxysuccinimide, pyridine, bovine serumalbumin (BSA), human serum albumin (HSA), dimethyl sulfoxide (DMSO), ovalbumin (OVA), polyethylene glycol (PEG), hypoxanthine–aminopterin–thymidine (HAT) medium, hypoxanthine–thymidine (HT) medium, and peroxidase-labelled goat anti-mouse immunoglobulins (HRP-IgG) were purchased from Sigma-Aldrich (USA). Australian fetal bovine serum was purchased from Thermo Fisher Bioengineering Materials (Beijing, China). The SP2/0 mouse-tumor cell line was obtained from our laboratory. All other chemicals and organic solvents were of analytical grade or better. Female Balb/c mice (6–8 weeks old, NO. 42000600000485) were bought from Three Gorges University (Yichang, China) and quality-tested by the Hubei Provincial Center for Disease Control and Prevention (Wuhan, China).
A full-wavelength microplate reader (BioTek, Winooski, VT, USA) and a UV spectrophotometer (Model 8453) were purchased from Agilent Technologies, Inc. (Santa Clara, CA, USA).