UTTAR PRADESH JOURNAL OF ZOOLOGY

This study investigated the preliminary physicochemical characteristics and in vitro biological activities of pectin extracted from the seagrass Syringodium isoetifolium. Seagrass samples were collected from coastal waters near Karankadu in October 2025, and the isolated fraction was subsequently examined for several pectin-associated properties. Dried seagrass material was subjected to acid extraction, ammonium oxalate treatment and ethanol precipitation. The recovered material was evaluated using qualitative biochemical reactions and Fourier-transform infrared (FTIR) spectroscopy. Antioxidant activity was assessed by the DPPH radical-scavenging assay, while inhibition of heat-induced albumin denaturation and α-glucosidase activity was used to evaluate additional biological properties. The extract exhibited the precipitation, viscosity and solubility characteristics described for pectin. FTIR absorption bands at 1586.16 and 1422.24 cm⁻¹ were consistent with carboxylate-associated functional groups, suggesting an anionic polysaccharide profile; however, the degree of esterification was not quantified. Across the reported assay series, DPPH radical-scavenging activity increased from 17.5% to 66.25%, albumin-denaturation inhibition increased from 8.8% to 78.4%, and α-glucosidase inhibition increased from 8.5% to 76.0%. The manuscript reports corresponding IC₅₀ values of approximately 740, 629 and 652 µg/mL, respectively. These results indicate concentration-related responses in three in vitro screening assays. Further quantitative structural characterisation and biological evaluation are required before the extract's composition, mechanisms of action or potential practical applications can be established.