Sinigrin hydrate

Sulfatase from Helix pomatia, sinigrin hydrate, l-ascorbic acid (AA), trichloroacetic acid (TCA), dl-dithiothreitol (DTT), N-ethylmaleimide (NEM), 2,2′-bipyridyl, iron (III) chloride (FeCl₃), 3-O-CQA (3-O-caffeoylquinic acid), 5-O-CQA (5-O-caffeoylquinic acid), butyl-isothiocyanate, caffeic acid (CA), 1,2-benzenedithiol, ß-mercaptoethanol (HPLC grade), methylene chloride (HPLC grade), sephadex A-25, sephadex C-25, acetonitrile (HPLC grade), methanol (HPLC grade), sulforaphane, sodium acetate, potassium phosphate, and orthophosphoric acid (H₃PO₄) were obtained from Sigma Chemical Co. (St. Louis, MO, USA). Desulfoglucoraphanin was obtained from Santa Cruz Biotechnology (Dallas, TX, USA).

Glucoraphanin potassium salt was purchased from Chromadex (Irvine, CA). Sinigrin hydrate and sulforaphane were provided by Sigma-Aldrich (St. Louis, MO). Citric acid, disodium hydrogen phosphate, ethylene diamine tetra acetic acid (EDTA), dimethyl sulfoxide (DMSO), glacial acetic acid, ammonium acetate, HPLC-grade methanol and HPLC-grade acetonitrile were purchased from RCI Labscan (Bangkok, Thailand), while HPLC-grade water was supplied by Sithiporn (Bangkok, Thailand).

Kimchi cabbage by-products (outer leaves and cortex) were collected from a kimchi manufacturing plant (Sup. Fig. 1 a, b). (−)-Sinigrin hydrate (GLS standard) and chitosan (low molecular weight, 50,000–190,000 Da) were purchased from Sigma-Aldrich (St. Louis, MO, USA). HPLC-grade water and methanol (MeOH) were purchased from Merck & CO., Inc. (Kenilworth, NJ, USA). Medium chain triglyceride (MCT), glycerol monostearate (GMS), and tween 80 (T80) were obtained from Daejung Chemicals (Seoul, Korea). Lipases from porcine pancreas, bile extract porcine, pepsin from porcine gastric mucosa, and pancreatin from porcine pancreas were purchased from Sigma-Aldrich (St. Louis, MO, USA).Fig. 1

Effect of extraction conditions on GLS content: (a) methanol concentration, (b) ultrasonication, (c) time, and (c) amplitude. Different letters indicate a significant difference at p < 0.05 (n = 3).

Fig. 1

Sinigrin hydrate, vanillic acid, amygdalin, L-canavanine, phloridzin dihydrate,
umbelliferone, rutin hydrate, salicin, gallic acid, naringin, sinapic acid,
gramine, caffeine, sucrose, allyl isothiocyanate, coumarin, methyl jasmonate,
brilliant blue FCF and sulforhodamine B were purchased from Sigma-Aldrich (St.
Louis, MO, USA). Glucoiberin potassium salt and glucobrassicin potassium salt
were purchased from Extrasynthese (Lyon, France). Gluconapin potassium salt and
gluconasturtiin potassium salt were purchased from ChromaDex (Irvine, CA, USA).
Quinine, chloroquine, denatonium and indole were purchased from Aladdin
(Shanghai, China). Salicylic acid and jasmonic acid were purchased from TCI (TCI
Shanghai, China). Berberine was purchased from Macklin (Shanghai, China).

Sulfatase from Helix pomatia, sinigrin hydrate, sephadex A-25, 3-O-caffeoylquinic acid (3-O-CQA), acetonitrile (HPLC grade), methanol (HPLC grade), sodium acetate, MeJA, and orthophosphoric acid were obtained from Sigma Chemical Co. (St. Louis, MO, USA). ET was purchased from Infra (Naucalpan, MEX, Mexico). Acetic acid was purchased from Desarrollo de Especialidades Quimicas (Monterrey, NL, Mexico). Desulfoglucoraphanin was obtained from Santa Cruz Biotechnology (Dallas, TX, USA).

All the reagents used were chosen of analytical grade. A phosphate buffer solution was prepared in distilled water using 50 mM KH₂PO₄ and 50 mM KCl, pH = 6.0, purchased from Carlo Erba. CB-PBNP powder was prepared using K₃Fe(CN)₆ and HCl 37% (w/w) obtained from Sigma Aldrich, and FeCl₃ obtained from Fluka. CB N220 of industrial standard grade was obtained from Cabot Corporation (Italy). N, N-dimethylformamide (DMF) was from Merck Millipore. Glucose, sinigrin hydrate, and GOx enzyme were purchased from Sigma Aldrich. Myr enzyme of 38 U/mL, 50 U/mg of specific activity, and purification factor of 71 was kindly provided by Dr. Eleonora Pagnotta from the laboratory of the Council for Research in Agriculture and Agrarian Economy (CREA) placed in Bologna (Italy). Indian mustard, brown mustard seeds (Brassica Juncea L.) used as a real matrix sample were purchased from a local market. The chronoamperometric analyses were performed using the chronoamperometric technique performed by a portable MultiEmStat³ (PalmSens, Netherlands) at a fixed potential of 0.0 V for 300 s.