1. Polystyrene-type resin used for peptide synthesis: application for anion-exchange and affinity chromatography
Regina S H Carvalho, Danielle A Ianzer, Luciana Malavolta, Mauricio M Rodrigues, Eduardo M Cilli, Clovis R Nakaie J Chromatogr B Analyt Technol Biomed Life Sci. 2005 Mar 25;817(2):231-8. doi: 10.1016/j.jchromb.2004.12.008.
This paper deals with an unusual application for a copolymer of styrene-1% divinylbenzene bearing high amount of aminomethyl groups for anion-exchange and affinity chromatography. The so-called aminomethyl resin (AMR), to date only employed for peptide synthesis, swelled appreciably in water and was used successfully to purify negatively charged peptides. By correlating swelling degree of beads with pH of the media, it was possible to estimate that the AMR amino group pK(a) is approximately 5.5. In addition, the synthesized acetyl-(NANP)3-AMR succeeded in the affinity interaction with large antibody molecules related to malaria transmission and raised previously against this dodecapeptide sequence.
3. Development of self-indicating resin
Osamu Ichihara, David Sampson, Mark Whittaker, Mark Bradley, Jin Ku Cho Comb Chem High Throughput Screen. 2007 May;10(4):261-7. doi: 10.2174/138620707780636592.
Previously, we have reported the development and application of self-indicating resins (SIR), materials which can indicate presence or absence of amines in the reaction solution by the conspicuous color change of a phenolsulfophthalein type dye immobilized on resin beads [2a]. Although the functionality necessary for attaching the dye to the resins could be readily introduced by the Suzuki-Miyaura coupling during the synthesis of the SIR 1, this approach was only applicable to the dyes containing suitable functionality for the cross-coupling reaction. In this article we describe a new approach of immobilizing the indicating dyes onto the resin support. The dyes suitable for loading onto aminomethyl polystyrene (PS) resin were prepared by Friedel-Crafts reaction of 2-sulfoterephthalic anhydride with a wide range of phenols. Using this new route, the SIR 6c was readily prepared in >100g quantities. Use of the SIR 6c in the synthesis of a 144 member urea library was demonstrated and the SIR successfully indicated the endpoint of the reaction between amines and isocyanates.
