The Preparation and Properties of Silicon-Carbohydrate Compounds

Abstract

Silicon is widely distributed in plant and animal organisms and it has been reasonably well established that the element is structurally bound in biopolymers such as pectin. However, the major problem in studying the biological role of silicon is that virtually nothing is known of how silicon is bound within plant and animal polymers. The rather sketchy evidence which exists indicates that in nature silicon is bonded to carbohydrate systems. The aim of the present project was to obtain further information on the bonding of silicon in natural systems. Attempts were made to prepare compounds of the type (CHy)4Si which might serve as models for natural silicon derivatives. Two main modes of approach to these syntheses were followed. The first was to react unprotected monosaccharides with new and modified silylating agents, the second mode involved the reaction of protected monosaccharide derivatives with standard silylating agents. Many modifications of these two major approaches were investigated. In a number of cases, there was evidence that products of the required type had been prepared. These compounds, however, were generally highly labile and proved difficult to characterize. A further reference to natural silicon derivatives was studied, that was the degradation of a variety of pectins, pectins are known to have a fairly high silicon content and it was hoped that degradation and separation would yield specific silyl organic compounds.