Jnm ecz500r s1

All experiments were conducted using anhydrous solvents and oven-dried glassware and were carried out using a CEM microwave synthesizer. High-resolution mass spectra were recorded using an ESI source and a quadrupole/TOF mass spectrometer. Solvents were distilled using standard methods and stored in 4Å and 3Å molecular sieves. JEOL JNM-ECZ500R/S1 instrument was used to record ¹H (500 MHz) and ¹³C (126 MHz) spectra. The chemical shifts for ¹H and ¹³C were referenced to the residual signals of CDCl₃¹H NMR δ 7.26 and δ 77.16 for ¹³C NMR, and DMSO-d₆¹H NMR δ 2.5 and δ 39.52 for ¹³C NMR, reported in parts per million (ppm) at 25 °C. Coupling constants were expressed in hertz (Hz). Thin-layer chromatography was used to monitor reactions, carried out on 0.25 mm Merck silica gel plates (60F-254), with spots visualized using phosphomolybdic acid and 10% H₂SO₄ in ethanol. Reagents were purchased from TCI, Merck, Sigma Aldrich, and other sources.

Furfuryl-modified gelatin was synthesized through a coupling reaction between the amine groups of gelatin and furfuryl glycidyl ether. First, gelatin (2 g) was dissolved in 80 mL of deionized (DI) water and the pH was adjusted to 11 using 1 N NaOH. Next, furfuryl glycidyl ether (250 μL) was mixed with DMSO (20 mL). Then, these two solutions were mixed and incubated at 60 °C for 30 h with gentle stirring. The pH of the furfuryl-gelatin solution was adjusted to 7 and dialyzed for 48 h using a dialysis membrane (MWCO 1000 Da, Spectrum Laboratories, Inc., Rancho Dominguez, CA, USA). The dialyzed furfuryl-gelatin solution was lyophilized and then washed four times with acetone and once with ether. The solution was then dried at 37 °C for 6 h and stored for further use.
The synthesized furfuryl-gelatin was analyzed using ¹H-NMR (500 MHz) using JNM-ECZ500R/S1 (JEOL, Tokyo, Japan). Gelatin and furfuryl-gelatin were dissolved in D₂O (50 mg/mL) for the measurements.
Fourier-transform infrared (FT-IR) spectra were obtained at room temperature using an iS50 spectrometer (Thermo Fisher Scientific, Waltham, MA, USA). The transmittance of the lyophilized samples was measured using KBr pellets within the range of 4000–500 cm^–1.

Organic solvents (methanol, ethyl acetate, chloroform, n-hexane) used were pro analytical grades obtained from Merck. Silica gel F
₂₅₄, Silica gel PF
₂₅₄, (Merck), RPMI 1640, Fetal Bovine Serum, Penicillin-Streptomycin, Fungizon, Sodium bicarbonate (Gibco), HEPES (Invitrogen), Phosphate Buffered Saline, MTT (Sigma Aldrich cat. M5655), Doxorubicin (Sigma Aldrich). Infrared (KBr) spectrum was obtained from spectrophotometer (Shimadzu) using a method previously described by Ashokkumar and Ramaswamy
⁷
. Ultraviolet spectrum (CHCl
₃) was obtained from UV spectrophotometer (Hitachi UH 5300). Sample (1 mg) were diluted in 1 mL CHCl
₃ and was run between 200–400 nm. Spectra of
¹H- and
¹³C- NMR in CDCl
₃ solvent were measured using JEOL JNM-ECZ 500R/S1 at 500 MHz.