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

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.

Graphical abstractA convenient photosynthesis of uniformly [14C]-labelled d-glucose, d-fructose and sucrose, and chemical synthesis of methyl-α-d-glucopyranoside ([U-14C]-glucose)/[14C]–AMG, in short.The photosynthesis of d-[U-14C]-glucose, and two other [14C]-sugars (fructose and sucrose) with high specific activity using ‘Canna indica’ leaf, 14CO2 and water in presence of light is presented in this paper. Further, the d-[U-14C]-glucose obtained was converted to methyl-α-d-glucopyranoside ([U-14C]-glucose)/[14C]–AMG having 98% radiochemical purity and specific activity in the range of 250–300 mCi/mmole, using montmorillonites (M+n-monts). Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Synthesis of methyl α d-glucopyranoside ([U-14C] glucose) has not been reported using M+n-monts. ► M+n-monts are reusable, economical, environmentally benign, and simplify workup procedures. ► [14C]–AMG in a radiochemical yield of 65% with more than 98% radiochemical purity has been realized. ► No carrier was added for obtaining a high specific activity finished product. ► A photosynthetic device, superior in design and performance, has been used efficiently.