Recently learned from Nankai University, Professor Chen Gong of the State Key Laboratory for organic chemistry has developed a chemical synthesis of a powerful cyclic polypeptide compound, which has made the "highly difficult peptide ring" reaction in the chemical industry more efficient and controllable. As an important breakthrough in the field of synthetic chemistry of cyclic peptides, the study also provides a novel design tool for the development of polypeptide drugs. Relevant research results are published in the latest issue of nature chemistry.

It is said that, compared with the traditional small molecule compounds, the polypeptide compound, which is made up of a variety of amino acid units, has unique advantages and potential in the construction of a larger molecular structure. The known cyclo peptides include anti-tumor, anti HIV, antiseptic, antimalarial, hypnotic, inhibition of platelet aggregation and immunity. Inhibition of many aspects of biological activity. Previous studies have shown that the chain like polypeptide "ring" can significantly improve the polypeptide drug resistance in many aspects, such as structural strength, cell transmembrane, metabolic stability and so on. Although the synthetic chemistry of cyclin has made great progress over the past few decades, it still has great limitations. How to make these "big" peptide molecules "shape" as ideal three-dimensional structure (ring peptide) and have good pharmacological properties still have great challenges.

Inspired by the biosynthesis of natural products of cyclic peptides, the Chen bow team selectively activates the originally very inert alkyl hydrocarbon bonds on the chain polypeptide substrates by metal catalysis, and produces intramolecular coupling with the aromatic amino acid side chains with iodine substituted amino acids to produce various annular products. The method uses palladium to catalyze the activation of alkyl hydrocarbon bonds in the synthesis of complex peptides, which can "tame" many chain polypeptide precursors that are difficult to ring, so that they are "good" to close the ring. Because of the unconventional "hydrocarbon activation" synthesis strategy, the method is simple, efficient, and has a wide range of substrates. It not only overcomes the substrate dependence that perplex the "polypeptide ring" reaction for a long time, but also produces a three-dimensional cycP skeleton with a unique "benzene ring support frame" structure, which is for the construction of different volumes. The cyclic peptide compounds provide a new general approach, and also provide a solid foundation for the discovery of more good lead drug activity novel cyclic peptide compounds and the development of targeted peptide drugs.