The isolation, characterization, and bio-activity of two polysaccharides in Rhodomyrtus tomentosa (Aiton) Hassk. fruits

Rhodomyrtus tomentosa (Aiton) Hassk. (R. tomentosa), widely distributed across China, Vietnam and other regions, offers significant health benefits to humans due to its antioxidant and antibacterial properties. Following purification, two polysaccharides, designated T1 and T2, were isolated from R. tomentosa. The antioxidant activity, antibacterial properties, and characterisation of R. tomentosa fruit polysaccharides were investigated post-isolation and purification. The structures of T1 and T2 were characterised using ion chromatography, Fourier transform infra-red spectroscopy (FT-IR), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM). The findings indicated that both T1 and T2 consist of five monosaccharides. The molecular conformation of T2 is speculated to be spherical. Additionally, the antioxidant activity of T2 was found to be greater than that of T1 but less than that of the crude polysaccharide. These results lay a foundation for further exploration of the medical value of R. tomentosa and the utilisation of its resources.