tailieunhanh - Ebook Analysis and purification methods in combinatorial chemistry: Part 2

(BQ) Part 2 book "Analysis and purification methods in combinatorial chemistry" has contents: Strategies and methods for purifying organic compounds and combinatorial libraries; high throughput purification - triage and optimization; parallel hplc in high throughput analysis and purification,.and other contents. | PART III HIGH-THROUGHPUT PURIFICATION TO IMPROVE LIBRARY QUALITY CHAPTER 10 STRATEGIES AND METHODS FOR PURIFYING ORGANIC COMPOUNDS AND COMBINATORIAL LIBRARIES JIANG ZHAO, LU ZHANG, and BING YAN . INTRODUCTION The absolute purity requirement of combinatorial library compounds delivered for biological screening has been raised. Improving compound purity is the most effective way to remove any ambiguity in the screening data. Even with the rapid advances in solid-phase and solution-phase synthesis and the intensive reaction optimization, excess reagents, starting materials, synthetic intermediates, and by-products are often found along with the desired product. Furthermore the strong solvents used to swell the resin bead for solid-phase synthesis and the scavenging treatment in solution-phase reactions often introduce additional impurities leached from resins and plastic plates. Therefore high-throughput purification has become an indispensable technology in all combinatorial chemistry and medicinal chemistry laboratories. Throughput is a main consideration in purifying combinatorial libraries. Parallel synthesis often produces large numbers of samples, ranging from hundreds to thousands per library. Parallel processes are therefore preferred as productivity is multiplied by the number of channels. A 10-channel flash column chromatography system is presented by Isco, and 96-channel systems of solid-phase extraction (SPE) and liquid-liquid extraction (LLE) are also reported. The off-line process is often used as a time-saving measure in preparative HPLC where parallel processing is difficult. Column re-equilibrating and samples loading can be done off-line to reduce the cycle time. Cost is a deciding factor in conducting high-throughput purification. Lengthy purification, scale-up in library production, low-purification recovery yield, plus all the reagents and accessories used for purification boost Analysis and Purification Methods in Combinatorial Chemistry, .