Synthesis of new hydrophobic adsorbents based on homologous series of uncharged alkyl sulphide agarose derivatives.
A homologous series of uncharged thioalkyl derivatives of agarose were prepared by a simplified synthetic route and their adsorption behaviour towards human serum proteins was evaluated and compared with that of a commercially available alkyl ether derivative of agarose. The influence of the spacer arm length on the adsorption efficiency was also investigated. The degree of substitution of the derivatives can be estimated conveniently by sulphur analysis. The four different types of thiolkyl derivatives (C6, C8, C12 and C14) investigated here behave in all respects like hydrophobic adsorbents. The coupling yield obtained is high (75% or more) and is better than that obtained by alternative synthetic routes reported so far. The adsorption capacity towards serum proteins of the various derivatives increases with increasing alkyl chain length and degree of substitution. Desorption is achieved by a progressive decrease in the polarity of the eluent and the recovery of the applied material is in the range 80-90%. The role played by the thioether as a possible modulator of the observed hydrophobic adsorption is discussed. For the group separation of serum proteins the optimum adsorbent, as regards capacity combined with ease of elution of adsorbed material, should be substituted with chains of six or eight carbon atoms and have a ligand concentration in the range 80-120 mumole g-1 dry gel.
D000327:Adsorption; D001798:Blood Proteins / Q000302:isolation & purification; D055598:Chemical Phenomena; D002621:Chemistry; D006801:Humans; D012685:Sepharose / Q000138:chemical synthesis*
D001798:Blood Proteins; D012685:Sepharose