5845-61-4Relevant articles and documents
En Route to a Heterogeneous Catalytic Direct Peptide Bond Formation by Zr-Based Metal-Organic Framework Catalysts
Conic, Dragan,De Azambuja, Francisco,Harvey, Jeremy N.,Loosen, Alexandra,Parac-Vogt, Tatjana N.,Van Den Besselaar, Maxime
, p. 7647 - 7658 (2021/06/30)
Peptide bond formation is a challenging, environmentally and economically demanding transformation. Catalysis is key to circumvent current bottlenecks. To date, many homogeneous catalysts able to provide synthetically useful methods have been developed, while heterogeneous catalysts remain largely restricted to the studies addressing the prebiotic formation of peptides. Here, the catalytic activity of Zr6-based metal-organic frameworks (Zr-MOFs) toward peptide bond formation is investigated using dipeptide cyclization as a model reaction. Unlike previous catalysts, Zr-MOFs largely tolerate water, and reactions are carried out under ambient conditions. Notably, the catalyst is recyclable and no additives to activate the COOH group are necessary, which are common limitations of previous methods. In addition, a broad reaction scope tolerates substrates with bulky and Lewis basic groups. The reaction mechanism was assessed by detailed mechanistic and computational studies and features a Lewis acid activation of carboxylate groups by Zr centers toward amine addition in which an alkoxy ligand on adjacent Zr sites assists in lowering the barrier of key proton transfers. The proposed concepts were also used to study the formation of intermolecular peptide bond formation. While intrinsic challenges associated with the catalyst structure and water removal limit a more general intermolecular reaction scope under current conditions, the results suggest that further design of Zr-MOF catalysts could render these materials broadly useful as heterogeneous catalysts for this challenging transformation.
Discovery of a novel inhibitor of nitric oxide production with potential therapeutic effect on acute inflammation
Zhu, Long-Qing,Fan, Xiao-Hong,Li, Jun-Fang,Chen, Jin-Hong,Liang, Yan,Hu, Xiao-Ling,Ma, Shu-Meng,Hao, Xiang-Yong,Shi, Tao,Wang, Zhen
supporting information, (2021/05/26)
Inflammation as a host's excessive immune response to stimulation, is involved in the development of numerous diseases. To discover novel anti-inflammatory agents and based on our previous synthetic work on marine natural product Chrysamide B, it and a series of derivatives were synthesized and evaluated for their anti-inflammatory activity on inhibition of LPS-induced NO production. Then the preliminary structure–activity relationships were conducted. Among them, Chrysamide B is the most potent anti-inflammatory agent with low cytotoxicity and strong inhibition on the production of NO (IC50 = 0.010 μM) and the activity of iNOS (IC50 = 0.082 μM) in LPS-stimulated RAW 264.7 cells. Primary studies suggested that the mechanism of action may be that it interfered the formation of active dimeric iNOS but not affected transcription and translation. Furthermore, its good performance of anti-inflammatory effect on LPS-induced multiple inflammatory cytokines production, carrageenan-induced paw edema, and endotoxin-induced septic mice, was observed. We believe that these findings would provide an idea for the further modification and research of these analogs in the future.
Chrysamide B derivative with anti-tumor activity and preparation and application of Chrysamide B derivative
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Paragraph 0061-0063; 0065, (2020/08/02)
The invention belongs to the field of medicinal chemistry, and particularly relates to a marine natural product Chrysamide B and a derivative thereof. The marine natural product Chrysamide B comprisesstereoisomers or pharmaceutically acceptable salts, solvates and prodrugs of the marine natural product Chrysamide B, general formulas are shown in a formula (I), a formula (II) and a formula (III).The invention also provides preparation and application of the compound. The compound has an anti-cancer effect; the compound has good inhibitory activity on digestive system cancers, leukemia, livertumors, non-small cell lung cancers, cervical cancers, breast cancers and the like and has the effects of inducing tumor cell apoptosis, activating apoptosis protein expression, retarding cycle, inhibiting proliferation and the like and is a potential antitumor drug.
