4 methylumbelliferyl oleate

Optical rotations were obtained with a Perkin-Elmer 341 polarimeter (Boston, MA, USA). UV spectra were measured on a Milton Roy Spectronic 300 Array spectrophotometer, and IR was recorded on a Perkin-Elmer FT-IR 1760x spectrophotometer (Boston, MA, USA). High-resolution electrospray ionization mass spectra (HR-ESI-MS) were recorded with a Bruker micro TOF mass spectrometer (Billerica, MA, USA). NMR spectra were obtained with a Bruker Avance DPX-300 FT-NMR spectrometer (Billerica, MA, USA). Vacuum liquid chromatography (VLC) and column chromatography (CC) were performed on silica gel 60 (Merck, 70–230 µm, Darmstadt, Germany), silica gel 60 (Merck, 230–400 nm) or Sephadex LH-20 (Pharmacia, Piscataway, NJ, USA). Yeast α-glucosidase enzyme, p-nitrophenol-α-d-glucopyranoside, pancreatic lipase, and 4-methylumbelliferyl oleate were purchased from Sigma Chemical, Inc. (St. Louis, MO, USA), and acarbose from Fluka Chemical (Buchs, Switzerland).

Phosphate buffered saline (PBS, L0615-500), RPMI 1640 medium (L0496-500), penicillin-streptomycin (L0022-100), and fetal bovine serum (FBS, S1860-500) were purchased from Biowest (Nauillé, France). Pancoll Human (P04-601000) was from PAN-Biotech (Aidenbach, Germany). Gentamicin (15710-049) was purchased from Life Technologies (Paisley, UK). Dimethyl sulfoxide (DMSO, 113635509) was purchased from Chempur (Piekary Śląskie, Poland). Formic acid (100264) was obtained from Merck (Darmstadt, Germany). An EnzChek™ Ultra Amylase Assay Kit was purchased from (Invitrogen, Pailey, UK). Acarbose (A8980-1G), orlistat (O4139-25MG), 4-methylumbelliferyl oleate (MUO, 75164-100MG), salivary α-amylase (A0521-2.5KU, 170.1 units/mg), pepsin (P1725-100G, >400 U/mg protein), pancreatin from porcine pancreas (P1750-100G), as well as bile extract porcine (B8631-100G) from Sigma-Aldrich Chemie GmbH (Steinheim, Germany) were used. Tris-HCl buffer consisted of 13 mM Tris-HCl (Promega Corporation, Madison, WI USA), 150 mM NaCl, and 1.3 mM CaCl₂ (both form POCH, Gliwice, Poland). A brain heart infusion (BHI, P-0051) was purchased from BTL (Łódź, Poland).
Acetonitrile HiPerSolv Chromanorm^® (20060.320) was purchased from VWR Chemicals (Radnor, PA, USA). Ethyl acetate (141-78-6) was purchased from POCH (Gliwice, Poland). HPLC grade methanol (106009) was purchased from Merck (Darmstadt, Germany).

Twenty-two batches of AL were collected from different areas in China, and the sample origins are provided in Supplementary Table S1. The voucher specimens, identified by Associate Professor Long Guo have been deposited in Traditional Chinese Medicine Processing Technology Innovation Center of Hebei Province, Hebei University of Chinese Medicine.
Reference standards of neochlorogenic acid, chlorogenic acid, isochlorogenic acid B and isochlorogenic acid A were purchased from Chengdu Must Bio-Technoligy Co., Ltd. (Chengdu, China). The purities of these compounds were determined to be higher than 98% by high performance liquid chromatography with diode array detector. The chemical structures of the four compounds are shown in Supplementary Figure S1. Porcine pancreatic lipase (type II) and 4-methylumbelliferyl oleate were purchased from Sigma-Aldrich (St Louis, MO, United States).
HPLC grade methanol, acetonitrile and formic acid were obtained from Fisher Scientific (Pittsburgh, PA, United States). Ultrapure water was prepared by a Synergy water purification system (Millipore, Billerica, United States). Other chemicals and reagents were of analytical grade.