Preparation of ABNO on Scale and Analysis by Quantitative Paramagnetic NMR
摘要:
A practical, safe, and scalable synthesis of the stable nitro-oxide radical catalyst ABNO was developed. This process is chromatography-free and avoids the Wolff-Kishner reduction. H-1 NMR data for this paramagnetic compound were obtained that allowed an assessment of its chemical purity. Impact sensitivity test data for solid ABNO are also reported.
Chemical modifications' of native proteins can facilitate production of supernatural protein :functions that are not easily accessible by complementary methods relying on genetic manipulations. However, accomplishing precise control over selectivity while maintaining structural:. integrity and homogeneity still represents a fOrmidable, challenge. Herein, we report a transition metal-free method for tryptophan-selective bioconjugation of proteins that is based on an organoradical and operates under ambient conditions. This method exhibits low levels of cross-reactivity and leaves.higher-order structures of the protein and various functional groups therein unaffected: The strategy to,target less abundant amino acids contributes to the formation of structurally homogeneous conjugates, which may even be suitable for protein. crystallography. The absence of toxic metals and biochemi-i cally incompatible conditions allows a rapid functional- modulation of native proteins such as antibodies and pathogenic aggregative proteins, and this method may thus easily find therapeutic applications.
Electron loss from 1,3,3-trimethyl-2-azabicyclo[2.2.2]octane derivatives. Is .sigma.-coupling thermodynamically important?
作者:Stephen F. Nelsen、Richard J. Qualy、Peter M. Gannett