DENSITOMETRIC DETERMINATION OF SALICIN IN WILLOW STEM BARK

Most of the salicin present in willow stem bark occurs as labile glyco sides(e.g, salicin, salicortin, 2-O'-acetylsalicortin, 3-O'-acetylsali cortin, tremulacin, and fragilin). On alkaline hydrolysis, these acyla ted derivatives decompose to salicin; in this way, the total amount of salicin can be determined. A HPTLC method has been developed for the quantitative determination of salicin in stem bark before and after al kaline hydrolysis. The mobile phase used for the separation is a modif ication of one described in the literature [1]. A double or a triple m igration is necessary to sep arate salicin from other components of th e extract. The results have been compared with those obtained after bi dimensional chromatography using two phases described for the quantita tive evaluation of salicin [2,3]. To check that separation was complet e, the spectrum of salicin obtained from willow extracts was superimpo sed on that of a salicin standard. Quantification was performed at lam bda = 270 nm, the wavelength of maximum absorption in the UV spectrum of salicin.