56-41-7Relevant 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.
Direct monitoring of biocatalytic deacetylation of amino acid substrates by1H NMR reveals fine details of substrate specificity
De Cesare, Silvia,McKenna, Catherine A.,Mulholland, Nicholas,Murray, Lorna,Bella, Juraj,Campopiano, Dominic J.
supporting information, p. 4904 - 4909 (2021/06/16)
Amino acids are key synthetic building blocks that can be prepared in an enantiopure form by biocatalytic methods. We show that thel-selective ornithine deacetylase ArgE catalyses hydrolysis of a wide-range ofN-acyl-amino acid substrates. This activity was revealed by1H NMR spectroscopy that monitored the appearance of the well resolved signal of the acetate product. Furthermore, the assay was used to probe the subtle structural selectivity of the biocatalyst using a substrate that could adopt different rotameric conformations.
Inherently chiral dialkyloxy-calix[4]arene acetic acids as enantiodiscriminating additives for high-performance liquid chromatography separation of d,l-amino acids
Kalchenko, Olga I.,Trybrat, Oleksandr O.,Yesypenko, Oleksandr A.,Dyakonenko, Viktoriya V.,Shishkina, Svitlana V.,Kalchenko, Vitali I.
, p. 722 - 730 (2021/08/26)
Inherently chiral dialkyloxy-calix[4]arene acetic acids with asymmetric placement of substituents on the lower rim of the macrocycle were first studied as enantiodiscriminating additives to the mobile phase MeCN/H2O/HCOOH (75/25/0.02 by volume) in the high-performance liquid chromatography (HPLC) separation of d,l-alanine and d,l-valine on the achiral stationary phase ZORBAX Original CN. The dependence of enantio-binding properties on the position of alkyl groups is demonstrated. The highest resolution (1.65) and enantioselectivity (1.80) were obtained for the 1,2-dipropyloxy-calix[4]arene acetic acid.