Abstract
Poria cocos (Schw.) Wolf (Fushen) is valued for its nutritional and therapeutic properties. Fushen is commonly processed into slices of different shapes and sizes. We quantified alkali-soluble and water-soluble polysaccharides, total amino acids, and triterpenoids in Fushen slices of varying geometries (square: 1-9 cm width; round: 1-6 cm radii). Results showed that triterpenes and water-soluble polysaccharides initially decreased and then stabilized with increasing slice size, while total amino acids accumulated progressively, indicating spatial metabolic heterogeneity in Fushen. To map metabolite distribution, we segmented the Fushen into seven concentric zones and profiled the metabolites using a widely targeted metabolomics approach. A total of 359 metabolites were identified. The fungal symbiotic matrix exhibited metabolic profiles similar to the intermediate regions, while peripheral regions maintained comparable levels of triterpenes, saccharides, and amino acid derivatives. This study provides a detailed metabolomic blueprint of Fushen and offers insights for standardized processing and optimized medicinal use.