An active heteropolysaccharide from the rinds of Garcinia mangostana Linn.: Structural characterization and immunomodulation activity evaluation.

•An active heteropolysaccharide, GMP70-1, was isolated from G. mangostana for the first time.•The structure and morphology of GMP70-1 were characterized for the first time.•GMP70-1 was shown to have a single-helix structure.•GMP70-1 significantly enhanced the phagocytosis and the secretion of cytokine of RAW264.7 cells.•An in vivo zebrafish screening confirmed GMP70-1 to have immunomodulatory effects.