Agilent 1100 binary pump instrument

Ultraviolet–visible (UV–Vis) spectra were recorded on a Jasco V-730 spectrophotometer (Lecco, Italy).
Nuclear magnetic resonance (NMR) spectra were recorded at 400 MHz on a Bruker instrument (Milan, Italy).
HPLC analyses were performed on an Agilent 1100 binary pump instrument (Agilent Technologies, Milan, Italy) equipped with a UV–Vis detector, using an octadecylsilane-coated column, 250 mm × 4.6 mm, 5 µm particle size (Phenomenex SphereClone ODS, Bologna, Italy) at 0.7 mL/min, and the following gradient: 0.1% formic acid (eluent a)/methanol (eluent b): 40% b, 0–10 min; from 40 to 80% b, 10–47.5 min. The detection wavelength was set at 280 nm.
Liquid chromatography–mass spectrometry (LC–MS) analysis was performed on an HPLC 1100 VL series instrument (Agilent Technologies) with an electrospray ionization source in positive ion mode (ESI+). An Agilent Eclipse XDB-C18, 150 mm × 4.60 mm, 5 µm (Agilent Technologies) was used, with the same eluent used for the HPLC analysis at a flow rate of 0.4 mL/min. Mass spectra were registered under the following conditions: nebulizer pressure 50 psi; drying gas (nitrogen) flow 10 L/min, at 350 °C; and capillary voltage 4000 V.

Gelatin type A from porcine skin (gel strength ~300 g bloom), 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium-chloride (DMTMM), chitosan, glacial acetic acid, 2,2-diphenyl-1-picrilhydrazyl (DPPH), ferric chloride (III) hexahydrate, and 2,4,6-tris(2-pyridyl)-s-triazine (TPTZ) were purchased from Sigma Aldrich (Milano, Italy) and used without any further purification. Phosphate buffer saline (PBS) 10× was purchased from VWR. DHICA and MeDHICA were prepared according to a procedure previously developed [36 (link),37 (link)].
The UV–Vis spectra were recorded on a Jasco V-730 Spectrophotometer (Lecco, Italy).
HPLC analyses were performed on an Agilent 1100 binary pump instrument (Agilent Technologies, Milan, Italy) equipped with a SPD-10AV VP UV–visible detector using an octadecylsilane-coated column, 250 mm × 4.6 mm, 5 μm particle size (Phenomenex Sphereclone ODS, Bologna, Italy) at 0.7 mL/min. Detection wavelength was set at 300 nm. Eluant system: 1% formic acid:acetonitrile, 85:15 v/v.