Rf 1501 pc spectrofluorometer

Semi-preparative high performance liquid chromatography was performed on Agilent 1100 Series liquid chromatograph (Agilent Technologies, Santa Clara, CA, USA) equipped with diode array detector (DAD; λ=520 nm, λ=450 nm), autosampler, and fraction collector; conditions: injection volume, 600 μL (2 mg/mL, methanol); column Zorbax Eclipse XDB C18 (250 mm x 9.4 mm; 5 μm); mobile phase (6 mL/min), water (40 %) and methanol (60 %). Sephadex-LH-20 purchased from GE Helthcare (Uppsala, Sweden) was used for column chromatography. Preparative TLC was performed by using silica gel P/UV254 with CaSO₄ (Machery-Nagel, Germany, 2 mm layer of adsorbent). Analytical TLC was performed on silica gel (Silica gel 60, layer 0.20 mm, Alugram Sil G, Mashery-Nagel, Germany). All spectroscopic measurements were performed with a double beam UV-Vis spectrophotometer model Cary 300 (Agilent Technologies, Santa Clara, USA) with 1.0 cm quartz cells. Fluorescence measurements were carried out using a RF-1501 PC spectrofluorometer (Shimadzu, Japan) equipped with a 150 W Xenon lamp source with a 1.0 cm path length quartz cell. Color reaction was measured spectrophotometrically on ELISA (2100C) 96-well microplate reader (Rayto, China).

Inosine (Ino) and 2-[4-(2-hydroxyethyl)piperazin-1-yl]ethane-sulfonic acid (Hepes buffer) were ordered from Acros Organics. All the other used solvents and substrates were ordered from Sigma. The melting points (Mp) of the new compounds were calculated on a Mel-Temp apparatus and were not corrected. The IR spectra of novel compounds were recorded using PerkinElmer Spectrum One FT-IR spectrometer on a KBr pellet. Mass spectrometry is done using a Waters Micromass Quattro II triple quadrupole mass spectrometer and MassLynx software. Microanalyses of C, H, and N were performed on CarloErba EA1108. Fluorescence data were obtained using an RF-1501 PC spectrofluorometer (Shimadzu, Japan).

2. D fluorescence spectra were collected on an RF-1501 PC spectrofluorometer (Shimadzu, Japan) with excitation at 295 nm, using a 150 W Xenon lamp source, 1.0 cm quartz cells and a thermostatic bath. Fluorescence spectra were recorded at 298 K in the range of 300–450 nm. The widths of the excitation and emission slit widths were both fixed at 10 nm. Synchronous fluorescence spectra were collected on an RF-6000 spectrofluorometer (Shimadzu, Japan) at 298 K. The wavelength interval (Δλ) for the synchronous scan spectra varied between 15 and 60 nm to assess the alterations in the microenvironment surrounding the aromatic amino acid residues Tyr and Trp, respectively. Double system. Synchronous fluorescence spectra of the HSA-TGC system were measured at 298 K. In all experiments, the concentration of the HSA was kept at 2 μM, while the concentration of the TGC varied from 0 to 1 × 10⁻⁵ M.
Triple systems. Experimental details of the interaction of HSA-TGC-CAF and HSA-TGC-FLAVs systems (FLAVs = CAT, DIO, QUE) were observed at 298 K. The UV–vis and fluorescence spectra of HSA (2 μM) and HSA-CAF and HSA-FLAVs (molar ratio 1:1) were recorded in the absence and presence of increasing amounts of TGC (0 to 1 × 10⁻⁵ M). The resultant mixtures were incubated at 298 K.