Ifs 55

Optical rotation values were recorded on a polarimeter (Anton-Paar MCP 200; Austria). Infrared (IR) spectra were obtained with a Fourier transform infrared spectrometer (IFS-55; Bruker). A Shimadzu UV-1700 spectrophotometer (Shimadzu, Kyoto, Japan) was used to obtain the ultraviolet (UV) spectra. The NMR spectra were recorded using ARX-400 and AV-600 spectrometers (Bruker) with TMS as an internal standard. HRESIMS data were recorded on an Agilent G6520 Q-TOF spectrometer (Santa Clara, CA, USA). Column chromatography was conducted using silica gel (100–200 mesh and 200–300 mesh, Qingdao, China) and ODS (50 μm, Aichi, Japan) as absorbents, and thin-layer chromatography (TLC) plates (GF254) were purchased from Qingdao Marine Chemical Co. Ltd. (Qingdao, China). High-performance liquid chromatography (HPLC) was performed using a Shimadzu LC-20AR instrument equipped with an SPD-20A UV detector (Shimadzu, Kyoto, Japan) and a YMC Rp-C18 column (5 μm, 10 × 250 mm) (YMC, Kyoto, Japan). Cell apoptosis and intracellular ROS measurements were analyzed using a Becton Dickinson FACS Calibur System. All solvents used for isolation were of analytical grade, and the reagents for HPLC were of chromatographic grade.

The infrared absorption spectra of the in situ formed films were analyzed using a FTIR spectrophotometer (IFS-55; Bruker Co., Ltd., Faellanden, Zurich, Switzerland). The tablets were prepared by compressing the samples with potassium bromide. The peak variation of adsorption between 400 and 4000 cm⁻¹ was detected.

PSA–ODA was synthesized using pNC as a catalyst between PSA and ODA (Figure S1A). Briefly, ODA (135 mg, 0.5 mM), pNC (151 mg, 0.75 mM), and pyridine (60 μL, 0.75 mM) were dissolved in 5 mL dichloromethane (DCM) and stirred under nitrogen. After standing at room temperature for 3 h, 30 mL of dry ether was added. The resulting precipitate (p-ODA) was collected, washed with ether, and then redissolved in 10 mL formamide (FA). Then, PSA (150 mg, 0.5 mM) and triethylamine (65 μL, 0.5 mM) were added to the mixture and dissolved completely. After stirring at room temperature for 24 h under nitrogen, the reaction was terminated. Subsequently, the filtered mixture was dialyzed against distilled water using a cellulose ester membrane with an Mw cutoff of 1000 Da (Spectrum^®, Rancho Dominguez, CA). Finally, the retentate was lyophilized to yield PSA–ODA, which was analyzed by FT-IR (Bruker IFS 55, Billerica, MA) and ¹H NMR (Bruker 600-MHz, Billerica, MA).

Fourier-transform infrared (FT-IR) spectroscopy was carried out (IFS 55; Bruker Corp, Billerica, MA, USA) over the range 4,000–400 cm⁻¹, using the KBr pellet method.

The molecular complex of AZ, TNP, and AZN was crushed to fine powder using an agate mortar and pestle. The fine powdered samples were mixed with potassium bromide (1% wt ratio) and pressed hydraulically under pressure of 8 tons to make a disk. Potassium bromide (KBr) disks were analyzed using FTIR (Bruker IFS-55, 140 Germany) between 4,000 and 400 cm⁻¹ region.29 ,30 (link)