Soluble Carbohydrates in the Bark of Italian Prune (Prunus domestica) Trees

Abstract

AbstractBark samples were removed from 1‐year‐old stems of Italian prune trees at intervals throughout the growing season (June–August). Glucose, fructose, sucrose, traces of raffinose and a polyol were detected in ethanolic extracts of the bark. The polyol was isolated and shown to be d‐glucitol. The use of insoluble polyvinylpyrrolidone proved to be the best method for decolorizing bark extracts prior to quantitative analysis of ethanol‐soluble carbohydrates by paper chromato‐graphic methods. Glucitol was the major carbohydrate in the bark throughout the season. Sucrose was the major sugar, decreasing gradually as the season advanced. Fructose and glucose were found in lesser and about equal amounts. The amount of glucitol, glucose and fructose was high in June, decreased to a minimum in mid‐July, increased sharply in late July and early August and decreased later in the season.