Green grafting of tamarind seed xyloglucan with rosin: anti‐inflammatory and antidiabetic properties

Abstract Tamarind seed xyloglucan (XG), a naturally occurring polysaccharide with excellent biocompatibility and film‐forming properties, was successfully grafted with natural rosin through a one‐pot esterification approach to develop a novel bio‐based graft copolymer (XG‐ g ‐Rosin). The grafting conditions were optimized by varying the reaction temperature and rosin concentration with statistical validation. Successful graft formation was confirmed by Fourier transform infrared spectroscopy through the appearance of a characteristic ester carbonyl absorption band at 1694 cm −1 , while solid‐state 13 C NMR, Raman spectroscopy, X‐ray diffraction, thermogravimetric analysis and elemental analysis further verified the structural modification and improved thermal stability of the graft copolymer. An initial in vitro screening of the biological profile of XG‐ g‐ Rosin was conducted using α‐amylase inhibition, heat‐induced protein (bovine serum albumin) denaturation and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging assays. The graft copolymer exhibited concentration‐dependent α‐amylase inhibitory activity, reaching 32.13% inhibition at 100 μg mL −1 ; however, 50% inhibition was not achieved within the tested concentration range, indicating lower inhibitory potency than acarbose (IC₅₀ = 36.44 μg mL −1 ). In the protein denaturation assay, XG‐ g ‐Rosin demonstrated moderate anti‐inflammatory activity with an IC₅₀ value of 71.93 μg mL −1 , compared with 49.68 μg mL −1 for diclofenac sodium. In contrast, the graft copolymer exhibited relatively weak antioxidant activity in the DPPH assay, producing 38.11% radical scavenging at 1000 μg mL −1 . Overall, grafting of rosin onto tamarind seed XG successfully modified the macromolecular structure of the polysaccharide and imparted moderate in vitro α‐amylase inhibitory and anti‐inflammatory activities, although its antioxidant activity remained limited under the present experimental conditions. These findings provide preliminary in vitro evidence of the functional characteristics of XG‐ g ‐Rosin as a sustainable bio‐based graft copolymer, while comprehensive cell‐based and in vivo studies remain necessary to establish definitive biomedical efficacy. © 2026 Society of Chemical Industry.