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Phyllanthus niruri is a well-known herb widely used medicinally in Asia, Africa, and South America. Aqueous extraction of the intact plant provided an acidic arabinogalactan, which was characterized chemically, and its effects on peritoneal macrophage activation were determined. Methylation analyses and ¹³C NMR spectroscopy showed it to have a complex structure with a (1→4)-linked β-Galp main chain, substituted by rhamnose, galacturonic acid, arabinose, xylose, galactose, and glucose-containing side chains, with nonreducing end-units of arabinofuranose, xylopyranose, galactopyranose, and glucopyranose. In immunological studies, the arabinogalactan stimulated superoxide anion production, when tested using peritoneal macrophages of mice, but did not interfere with the nitric oxide pathway. Thus, traditional aqueous extraction methods, such as decoction and infusion, provide a major polysaccharide, which stimulates an intense biological response in macrophages:  this could represent an interesting approach in phytotherapeutic treatments.

Phyllanthus niruri is a well-known medicinal herb that is widely used in Asia, Africa, and South America. The characterization of two purified polysaccharides from the whole plant has been investigated. Methylation analysis and ¹³C NMR spectroscopy showed the chemical structure of two xylans. A hot 15% aqueous KOH fraction yielded a linear β-(1→4)-linked xylan, and 2% aqueous KOH afforded a complex acidic heteroxylan, with a (1→4)-linked β-Xylp main chain, substituted by rhamnose, arabinose, and 4-O-methylglucuronic acid side chains. These contained nonreducing end-units of arabinose, xylose, galactose, glucose, and nonmethylated glucuronic acid.

An arabinogalactan was obtained from the leaves of Maytenus ilicifolia by hot aqueous 2% KOH extraction, followed by a freezing−thawing process and anion-exchange chromatography. It consisted of arabinose, galactose, galacturonic acid, and rhamnose in a 69:20:6:5 molar ratio. Methylation analysis, partial acid hydrolysis, and ¹³C NMR spectroscopy indicated that it was an arabinogalactan containing a (1→4)-linked β-Galp main chain, substituted at O-6 with Ara units, which were in turn substituted at O-5 (Araf) and/or O-4 (Arap), O-3, O-3,5, and O-2,5. This arabinogalactan is probably linked to O-4 of some Rhap units of a type I rhamnogalacturonan, formed by repeating (1→4)-α-d-GalpA-(1→2)-α-l-Rhap groups.