2 phenethylamine

Production of BAs by B. breve IDCC4401 was investigated following the method described in a previous study [22 (link)] with minor modifications. The overnight cultured B. breve IDCC4401 was centrifuged at 2,300 ×g for 5 min at 4°C. An aliquot of 0.75 ml of supernatant was mixed with the same volume of 0.1 M HCl and filtered through a 0.45-μm membrane to extract BAs. For derivatization of the BAs, 1 ml of filtered BAs was incubated at 70°C for 10 min prior to addition of 200 μl of saturated NaHCO₃, 20 μl of 2 M NaOH, and 0.5 ml of dansyl chloride solution (10 mg/ml of acetone). The derivatized BAs were mixed with 200 μl of proline (100 mg/ml of H₂O) and incubated for 15 min at RT in the dark. The derivatized BAs were then separated and quantified using HPLC (LC-NETII/ADC, JASCO Inc., Japan) with an Athena C18 column (4.6 mm × 250 mm, ANPEL Laboratory Technologies Inc., China). Aqueous acetonitrile solution (Sigma-Aldrich Co., USA) was used as a mobile phase and the flow rate was adjusted to 0.8 ml/min. Finally, a peak was detected at 254 nm using a UV detector (UV-2075 Plus, JASCO Inc., Japan). The detected BAs were quantified from calibration curves of BAs including tyramine, histamine, putrescine, 2-phenethylamine, and cadaverine (Sigma-Aldrich Co.).

2-Phenethylamine (Sigma-Aldrich, St. Louis, MO, USA, 99%), tyramine (Sigma-Aldrich, 98%), dopamine hydrochloride (Sigma-Aldrich, 98%), N-hydroxyethyl acrylamide (Sigma-Aldrich, 97%), 2,2′-azobis(2-methylpropionitrile) (AIBN, Sigma-Aldrich, 98%), acryloyl chloride (Sigma-Aldrich, 97%), methacrylic anhydride (Sigma-Aldrich, 94%), polyethylene glycol diacrylate (PEGDA, Sigma-Aldrich, M_n 10 kg mol⁻¹, 97%) and sodium borate decahydrate (Sigma-Aldrich, 99.5%) were used without further treatment.

Dialdehydes, TFA, Pd/C, 3-nitro-1,8-naphthalic anhydride, hydrazine, hexylamine, benzylamine, 4-methylbenzylamine, 2-phenethylamine, triethylamine (99%), PVK, PBD, Bu₄NPF₆, NaOH, PPh₃, Pd(PPh₃)₂Cl₂ were purchased from Sigma Aldrich (Merck). Trimethylsilylacetyle (98%) and 4-bromobenzaldehyde (99%) were purchased from Acros Organic. Solvents were purchased from Sigma Aldrich (Merck) and Avantor S.A. PEDOT:PSS and glass with ITO surface were purchased from OSSILA.