Synthesis and comparative properties of two amide‐generating resin linkers for use in solid phase peptide synthesis
Well‐characterized resins of high purity are critical for effective solid phase peptide synthesis (SPPS). The quality of commercial (4‐methyl)benzhydrylamine‐resin (MBHA‐resin), used for the synthesis of peptide amides, is not consistent and residual ketone functionalities are frequently present. Such ketone or aldehyde impurities lead to the formation of acylation‐resistant deletion peptides in SPPS. To avoid these undesirable side reactions, we have optimized the preparation of two amide‐generating linkers, which, in combination with aminomethyl‐resin prepared directly from polystyrene resin, serve as alternatives to MBHA‐resin for peptide amide synthesis. Then we have explored their comparative properties in SPPS. Use of sonication in reductive amination facilitated the synthesis of both benzhydrylamine (BHA) and MBHA linkers. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.
A p-methylbenzhydrylamine resin for improved solid-phase synthesis of peptide amides
A p-methylbenzhydrylamine-resin, alpha-(p-tolyl)-amino-aminomethyl-functionalized copoly(styrene-1%-dvinylbenzene), was prepared for the improved solid-phase synthesis of peptide alpha-carboxamides. Following a Friedel-Crafts acylation of polymer beads, the resulting ketone resin was reductively aminated via the Leuckart reaction. A comparison of the relative acid stability of the p-methylbenzhydrylamine-(MBHA)-, benzhydrylamine (BHA)- and alpha-phenyethylamine-resins indicated that the p-methylbenzhydrylamine-resin provided the best yields of the model peptide carboxamides.
Evaluation of Impact of Yarn Count and Stitch Length on Pilling, Abrasion, Shrinkage and Tightness Factor of 1 ? 1 Rib Cotton Knitted Fabrics
This study investigates the impact of yarn count and stitch length of 100% cotton knitted fabrics. 1 × 1 ribs structured fabrics were used in this research work. The stitch length 2.50 mm, 2.52 mm, 2.60 mm, 2.70 mm, 2.80 mm and 2.96 mm were used of the yarn count of 26Ne, 28Ne and 36Ne. The areal densities of the grey fabrics were in various amounts. The impacts of yarn count and stitch length were measured concerning pilling resistance, abrasion resistance, and shrinkage and tightness factor. The result showed that the fabric pilling grade decreased while number of cycle increased. Abrasion resistance decreased but length wise shrinkage increased despite the fact that the stitch length increased. The results also exposed that the tightness factor of the fabric increased with the increase of the stitch length in both dyeing and washing state and finished state compared to grey state for the yarn count 26Ne and homogeneous result not found for yarn count 28Ne and 36 Ne. Evaluation of Impact of Yarn Count and Stitch Length on Pilling, Abrasion, Shrinkage and Tightness Factor of 1 × 1 Rib Cotton Knitted Fabrics