A convenient photosynthesis of uniformly [14C]-labelled d-glucose, d-fructose and sucrose, and chemical synthesis of methyl-α-d-glucopyranoside ([U-14C]-glucose)

Abstract

This paper describes a convenient procedure for the radiochemical preparation of d-[U-14C]-glucose, d-[U-14C]-fructose and [U-14C]-sucrose with high specific activity by photosynthesis using ‘canna indica’ leaf, [14C]-carbon dioxide and water in presence of light in a closed system. The [14C]-sugars formed were extracted, separated and then purified by paper chromatography. Further, the pure d-[U-14C]-glucose obtained was converted to methyl-α-d-glucopyranoside ([U-14C]-glucose) by glycosidation with methanol using (i) HCl, the conventional Fischer method (ii) heterogeneous organic cation exchange resin (Amberlite IR-120 (H+)) and (iii) heterogeneous inorganic cation exchanged montmorillonites called metal M+n-monts. The results indicated that the latter in the form of Fe+3-montmorillonite gave a better yield ( 65%) as compared to others (40–56%). The radiochemical purity of the no-carrier added product was more than 98%. The product retained its specific activity as that of the starting material which is in the range of 250–300 mCi/mmole (9.25–11.1 GBq/mmole), suitable for use as a radiotracer in biochemical investigations.