Structural Elucidation and Antiaging Activity of a Polysaccharide From <i>Crocus sativus</i> L. Petal

A novel polysaccharide, APPCS-1a, was isolated from Crocus sativus L. (saffron). Structural characterization revealed that it is primarily composed of arabinose and galactose in a molar ratio of 10.21:32.16, with an average molecular weight of 40.35 kDa. The backbone consists of alternating →2)-α-Rhap-(1→ and →4)-α-GalpA-(1→ residues, whereas side chains, including →4)-β-Galp-(1→ and →5)-α-Araf-(1→, T-β-Galp, T-α-Araf, and →3,6)-β-Galp-(1→, are attached at the C-4 position of Rhap. In aged mice, APPCS-1a administration significantly increased intestinal villus length, reduced crypt depth, and elevated goblet cell numbers. It also enhanced the activities of superoxide dismutase (SOD) and catalase (CAT) while reducing malondialdehyde (MDA) levels. Moreover, APPCS-1a exhibited synergistic antiaging effects by modulating the gut microbiota, notably through enriching beneficial bacterial taxa such as Lachnospiraceae and Lactobacillus, thereby supporting its potential as a microbiota‑targeted antiaging agent.