Extn. of anthocyanoside(s) e.g. malvoside or cyanoside - with acidified alcohol, drying by azeotropic distn., redissolving in acidified alcohol and prepn. with ketone(s)

摘要

Process for prepn. of pure, crystalline anthocyanosides, in the form of perfectly defined chemical species, starting from plant material contg. the anthocyanosides, by extn. with an alcoholic acid solvent, opt. after a preliminary washing of the starting material with an acidified ketone (e.g. acetone) to remove various impurities, is characterised in that after extn. of the anthocyanosides by means of the alcoholic acid solvent (e.g. acidified methanol) and evapn. of the extract to dryness, the residue is suspended in a solvent (e.g. n-butanol) which forms an azeotrope with water and azeotropically distilled to dehydrate the extract. The dried extract is dissolved in an alcoholic acid solvent (e.g. acidified methanol) and the anthocyanosides precipitated by addition of a ketone (e.g. acetone). The anthocyanosides are then crystallised from aqueous acid medium. Anthocyanosides have almost no toxicity and are strong dyes useful in the food, cosmetic and dermo-pharmaceutical industries. They are rapidly absorbed and increase capillary resistance, reduce capillary permeability and are used in ophthalmology, to give vascular protection and also have antiinflammatory radiation protecting, flood platelet aggregation inhibiting, antiviral, antineoplastic, enzyme inhibitory, and collagen biosynthesis affecting activity. Pharmacological and clinical tests are described.