thiourea and anthrone

Present study is a critical analysis and subsequent development of an analytical tool to measure the total sugar concentration in a carbohydrate mixture comprising both hexose and pentose. For this purpose, individual sugars were measured and standardized with anthrone reagent prepared in an ice-cold 98 % sulphuric acid followed by 3 min of boiling. Furthermore, regression analysis was performed after mathematical manipulation with the individual standards to formulate a linear relation between the absorbance of the mixture and its concentration, which satisfies Beer's law. It was found that the correlation coefficient for the equation is 0.973, when confidence interval was set at 0.95. The validation was done with a synthetic mixture of concentrations at 0.17 and 0.22 g/L (as range was ensured between 0.1 and 0.3 g/L) and also with the carbohydrate mixture as the prehydrolyzate obtained after the pretreatment of banana stem, which showed around 94.1 % accuracy and higher sensitivity with the cellulose present in the mixture. Thus, the method is evident to quantify the total sugars accurately obtained from hydrolyzed lignocellulosic biomass.

Topics: Anthracenes; Carbohydrates; Regression Analysis; Spectrophotometry; Sulfuric Acids; Thiourea

Catalyzed by the bifunctional tertiary amino-thiourea organocatalyst derived from epicinchona alkaloid, the asymmetric Michael addition of anthrone to enone was achieved in high yield with excellent enantioselectivity.

Topics: Anthracenes; Catalysis; Cinchona Alkaloids; Cross-Linking Reagents; Ketones; Stereoisomerism; Thiourea