U 2000 spectrometer

NMR spectra were recorded using a Bruker (MA, USA) BioSpin AV-300 spectrometer. Gel permeation chromatography (GPC) measurements were conducted using a system consisting of a JASCO (Tokyo, Japan) PU-2089 pump, a JASCO CO-2065 column oven, a JASCO RI-2031 refractive index detector, and a Shodex OHpak SB-804 HQ column (8.0 × 300 mm, SHOWA DENKO, Tokyo, Japan). A phosphate buffer (20 mM, pH 7.0) containing 20% N,N-dimethylformamide was used as the eluent at a flow rate of 0.5 mL/min at 30 °C. Pullulan samples were used as standards. Transmittance was recorded using a Hitachi (Tokyo, Japan) U-2000 spectrometer. Dynamic light scattering (DLS) analyses were conducted using an Otsuka Electronics (Osaka, Japan) ELSZ-1000 at 667 nm. The samples for transmittance and DLS analyses were prepared using 0.5 wt % in aqueous media and filtered through a membrane filter (0.45 μm). The fluorescence intensity was recorded using a JASCO FP-6500 spectrometer.

The following instructions were used to obtain spectroscopic data: melting points, Yanagimoto micromelting point apparatus (Yanaco New Science Inc., Kyoto, Japan); optical rotations, JASCO DIP-1000 digital polarimeter (JASCO Co., Tokyo, Japan); IR spectra, PerkineElmer 1720X FTIR spectrophotometer (PerkineElmer Inc., Waltham, MA, USA); UV spectra, HITACHI U-2000 spectrometer (Hitachi High-Technologies Co., Tokyo, Japan) (acetonitrile as a solvent); ¹H and ¹³C NMR spectra, Agilent VNMRS 600 spectrometer (Agilent Technologies Inc., Santa Clara, CA, USA) (CDCl₃ was used as the solvent and TMS as the internal standard); FABMS, JEOL JMS-7000 mass spectrometer (JEOL Ltd., Tokyo, Japan); CD spectra, JASCO J-820 spectrometer (JASCO Co.); and HPLC, JASCO PU-1586 (RI 1531) (JASCO Co.). The following experimental conditions were used for column chromatography: (silica gel, 70–230 mesh; Merck, Darmstadt, Germany); medium-pressure liquid chromatography (MPLC; silica gel, 230–400 mesh; Merck); and TLC (silica gel 60 F₂₅₄; Merck).