Interrogation of solution conformation of complex macrocyclic peptides utilizing a combined SEC-HDX-MS, circular dichroism, and NMR workflow

Ultra-clean pure shift NMR with optimal water suppression for analysis of aqueous pharmaceutical samples

Pure shift NMR experiments greatly enhance spectral resolution by collapsing multiplet structures into singlets and, with water suppression, can be used for aqueous samples. Here, we combine ultra-clean pure-shift NMR (SAPPHIRE) with two different internally encoded water suppression schemes to achieve optimal performance for small molecule and macrocyclic peptide pharmaceuticals in water and acetonitrile-water mixtures.

Purification and drying methods of sericin from Bombyx mori cocoons

Different methods of purification and drying of sericin were evaluated to obtain a material free of contaminating residues through the development of safer and sustainable environmental technology. Samples purified using different proportions of alcohol solvents and by freezing/thawing were compared, while drying was performed by lyophilisation and atomisation in a spray. No significant statistical differences were observed in the yield of the purification process compared with the evaluated methods. Thus, the freezing/thawing method has economic and environmental advantages over other methods. Drying by spraying and lyophilisation produced particles exhibiting different properties in terms of structure: β-sheets, random sheets, and β-turns. In general, these particles are amorphous. The particles obtained by spray drying were more luminous, soluble, and spherical. Thus, purification by freezing/thawing and drying by spray can be considered appropriate methodologies for obtaining contaminant-free sericin through sustainable environmental technology.