60-18-4Relevant articles and documents
Squamins C–F, four cyclopeptides from the seeds of Annona globiflora
Sosa-Rueda, Javier,Domínguez-Meléndez, Vanihamin,Ortiz-Celiseo, Araceli,López-Fentanes, Fernando C.,Cuadrado, Cristina,Fernández, José J.,Daranas, Antonio Hernández,Cen-Pacheco, Francisco
, (2021/08/04)
Four cyclic octapeptides, squamins C–F, were isolated from the seeds of Annona globiflora Schltdl. These compounds share part of their amino acid sequence, -Pro-Met(O)-Tyr-Gly-Thr-, with previously reported squamins A and B. Their structures were determined using NMR spectroscopic techniques together with quantum mechanical calculations (QM-NMR), ESI-HRMS data and a modified version of Marfey's chromatographic method. All compounds showed cytotoxic activity against DU-145 (human prostate cancer) and HeLa (human cervical carcinoma) cell lines. Clearly, A. globiflora is an important source of bioactive molecules, which could promote the sustainable exploitation of this undervalued specie.
Highly Stable Zr(IV)-Based Metal-Organic Frameworks for Chiral Separation in Reversed-Phase Liquid Chromatography
Jiang, Hong,Yang, Kuiwei,Zhao, Xiangxiang,Zhang, Wenqiang,Liu, Yan,Jiang, Jianwen,Cui, Yong
supporting information, p. 390 - 398 (2021/01/13)
Separation of racemic mixtures is of great importance and interest in chemistry and pharmacology. Porous materials including metal-organic frameworks (MOFs) have been widely explored as chiral stationary phases (CSPs) in chiral resolution. However, it remains a challenge to develop new CSPs for reversed-phase high-performance liquid chromatography (RP-HPLC), which is the most popular chromatographic mode and accounts for over 90% of all separations. Here we demonstrated for the first time that highly stable Zr-based MOFs can be efficient CSPs for RP-HPLC. By elaborately designing and synthesizing three tetracarboxylate ligands of enantiopure 1,1′-biphenyl-20-crown-6, we prepared three chiral porous Zr(IV)-MOFs with the framework formula [Zr6O4(OH)8(H2O)4(L)2]. They share the same flu topological structure but channels of different sizes and display excellent tolerance to water, acid, and base. Chiral crown ether moieties are periodically aligned within the framework channels, allowing for stereoselective recognition of guest molecules via supramolecular interactions. Under acidic aqueous eluent conditions, the Zr-MOF-packed HPLC columns provide high resolution, selectivity, and durability for the separation of a variety of model racemates, including unprotected and protected amino acids and N-containing drugs, which are comparable to or even superior to several commercial chiral columns for HPLC separation. DFT calculations suggest that the Zr-MOF provides a confined microenvironment for chiral crown ethers that dictates the separation selectivity.
Method for photolysis of amido bonds
-
Paragraph 0046; 0048-0049; 0098-0101, (2021/06/26)
The invention discloses a method for photo-splitting amido bonds, wherein the method is mild in reaction condition and can realize splitting of amido bonds by using illumination. The method for photo-splitting the amido bonds comprises the following steps: reacting 2,4-dinitrofluorobenzene with an amino group of a substance which contains alpha amino acid at the tail end and is shown as a structural formula I to generate a compound 1 represented by a structural formula II; and under light irradiation, carrying out amido bond cleavage reaction on the compound 1, wherein R1 is a side chain group of alpha-amino acid, and R2 is aryl, aliphatic hydrocarbon, -CH(R)-COOH or polypeptide.