An Anti-Emetic Principle of Pinellia ternata Tuber

Abstract

A polysaccharide fraction was isolated from the aqueous extracts of the tuber of Pinellia ternata (Thunb.) Breit, a Chinese drug, as an anti-emetic principle. It was antagonistic to the emetic action induced by apomorphine by the oral administration to leopard and ranid frogs. The polysaccharide, PT-F2-I, [α]²⁵ _D: (H₂O, c 1), separated by means of chromatography over sephacryl S-300 and TSK-G4000SW columns, was studied by the ¹³C-NMR spectra and methylation analysis combined with GC-MS. PT-F2-I was represented by an arabinan consisting of α(1→4)-linkages with α(1→2)-side chains as the main part, and oligosaccharide chains as the subunits involving fucose, glucose, galactose, rhamnose, and ribose in the ratio of 0.12, 0.1, 0.09, 0.05, and 0.05 provided that arabinose was 1.00. The presence of galacturonic acid was also proved by the carbazol colorimetric method, and calcium which is probably attached to it was determined by an X-ray energy spectrometer.