The invention relates to a process for introducing a thiol group a to a carbonyl group in a side chain of a protected a-amino acid, said protected a-amino acid having protecting groups on both the α-amine group and the a-carboxyl group. The process comprises a) if the side chain contains a functional group comprising a heteroatom bearing a hydrogen atom, protecting said functional group; b) treating the protected amino acid with a base of sufficient strength to abstract a hydrogen atom a to the carbonyl group, so as to form an anion; c) treating the anion with a reagent of structure Pr-S-L in which L is a leaving group and Pr is a thiol-protecting group, so as to introduce a Pr-S- group a to the carbonyl group; and d) converting the Pr-S- group to an H-S-(thiol) group. This process may be used to prepare ligated peptides.
Potent Cyclic Tetrapeptide for Lead Detoxification
作者:Tagwa A. Mohammed、Christoph M. Meier、Tadeáš Kalvoda、Martina Kalt、Lubomír Rulíšek、Michal S. Shoshan
DOI:10.1002/anie.202103217
日期:2021.5.25
Lead (Pb) is a ubiquitous poisonous metal, affecting the health of vast populations worldwide. Medications to treat Pb poisoning suffer from various limitations and are often toxic owing to insufficient metal selectivity. Here, we report a cyclictetrapeptide that selectively binds Pb and eradicates its toxic effect on the cellular level, with superior potency than state‐of‐the‐art drugs. The Pb‐peptide