Uh5300 uv spectrophotometer

DSPE-PEG bubble-like nanoparticles (DPBNPs) were used as carriers to encapsulate ARC. DPBNPs were prepared as previously described (Zeng et al., 2012 (link)). Briefly, ARC (20 mg) was dissolved in CHCl₃ (200 μL) by stirring. DSPE (50 mg, 0.06  mmoL, Ponsure Biological) and PEG 2000 (50 mg, 0.06  mmoL, Ponsure Biological) were dissolved in 200 μL chloroform. The two solutions were mixed in a 1:1 ratio to form a homogeneous organic phase. An additional 1 mL of deionized water was added to the mixture and mixed for 15 min. The solution was sonicated for 10 min using an ultrasonic mixer (Shanghai Bilon Instruments, Shanghai, China). Organic solvents were removed by rotary evaporation under reduced pressure. The deposited nanoparticle film was hydrated with deionized water to obtain a final concentration of 10 mg/mL. The nanoparticles were prepared by extrusion using Avanti mini-extruders (1 or 8 μm membranes). ARC@DPBNP absorbance properties were measured using a Hitachi UH5300 UV spectrophotometer (Tokyo, Japan), and their size was characterized using a Nano ZS zetasizer (Malvern, United Kingdom). The nanoparticle morphology was visualized using transmission electron microscopy (TEM, Tecnai G2-20).

The sample was dissolved in phosphate buffer at pH 7.0, and a UH5300 UV spectrophotometer (Hitachi, Tokyo, Japan) was used to determine the UV absorption peaks of each component at room temperature. The wavelength range was set to 190–400 nm.

Optical rotations were measured on a JASCO P-1020 digital polarimeter. UV spectra were recorded on a HITACHI UH 5300 UV spectrophotometer. ECD data were acquired on a J-815-150S Circular Dichroism spectrometer. IR spectra were recorded on a Nicolet-Nexus-470 spectrometer using KBr pellets. NMR spectra were acquired by a JEOL JEM-ECP NMR spectrometer (500 MHz for ¹H and 125 MHz for ¹³C), using TMS as an internal standard. HRESIMS were measured on Agilent 1290 Infinity II UHPLC/6530 Q-TOF MS for compounds 1 and 2, and Thermo MAT95XP high resolution mass spectrometer for compound 3. Samples were analyzed and prepared on a Hitachi L-2000 HPLC system coupled with a Hitachi L-2455 photodiode array detector and using a semi-prepared C₁₈ column (Kromasil 250 × 10 mm, 5 μm). Silica gel (Qing Dao Hai Yang Chemical Group Co.; 300–400 mesh) and Sephadex LH-20 (Amersham Biosciences) were used for column chromatography (CC). Precoated silica gel plates (Yan Tai Zi Fu Chemical Group Co.; G60, F-254) were used for thin-layer chromatography.