Structural identification and cytotoxic activity of a polysaccharide from the fruits of Lagenaria siceraria (Lau)

A water-soluble polysaccharide, isolated from fruiting bodies of Lagenaria siceraria, is composed of methyl-α-d-galacturonate, 3-O-acetyl methyl-α-d-galacturonate, and β-d-galactose in a ratio of nearly 1:1:1. Compositional analysis, methylation analysis, periodate oxidation, and NMR studies (1H, 13C, 2D-COSY, TOCSY, NOESY, HMQC, and HMBC) revealed the presence of the following repeating unit in the polysaccharide: This polysaccharide showed cytotoxic activity in vitro against human breast adenocarcinoma cell line (MCF-7).