Candesartan cilexetil is an angiotensin receptor antagonist widely used in the treatment of high blood pressure. This prodrug is metabolised into candesartan, which blocks the receptors AT1 for angiotensin II decreasing the blood pressure levels. During the development of a solid phase extraction procedure for the chromatographic determination of eight antihypertensive compounds, lack of linearity and reproducibility was observed only for candesartan cilexetil. Due to this fact, a stability study for this prodrug was performed. It showed that the lack of linearity and reproducibility was based on hydrolysis and transesterification processes which occurred during the drying step after elution with methanol into glass tubes. These phenomena could be reproduced artificially under basic conditions, which demonstrated the presence of basic residues in glass tubes. The study of this potential hydrolysis and transesterification reactions is very important to assure that labile drugs containing ester groups remain unaffected.
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http://dx.doi.org/10.1016/j.jchromb.2007.04.009 | DOI Listing |
Chin J Nat Med
January 2025
Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China. Electronic address:
Amoenucles A-F (1-6), six previously undescribed nucleoside derivatives, and two known analogs (7 and 8) were isolated from the culture of Aspergillus amoenus TJ507. Their structures were elucidated through spectroscopic analysis, single-crystal X-ray crystallography, and chemical reactions. Notably, 3 and 4 represent the first reported instances of nucleosides with an attached pyrrole moiety.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, U.K.
The catalytic competency of the ribosome in extant protein biosynthesis is thought to arise primarily from two sources: an ability to precisely juxtapose the termini of two key substrates─3'-aminoacyl and -acyl-aminoacyl tRNAs─and an ability to ease direct transpeptidation by their desolvation and encapsulation. In the absence of ribosomal, or enzymatic, protection, however, these activated alkyl esters undergo efficient hydrolysis, while significant entropic barriers serve to hamper their intermolecular cross-aminolysis in bulk water. Given that the spontaneous emergence of a catalyst of comparable size and sophistication to the ribosome in a prebiotic RNA world would appear implausible, it is thus natural to ask how appreciable peptide formation could have occurred with such substrates in bulk water without the aid of advanced ribozymatic catalysis.
View Article and Find Full Text PDFFood Chem
March 2025
Shaanxi Union Research Center of University and Enterprise for Functional Oil Engineering Technology, College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road, Yangling 712100, Shaanxi, PR China. Electronic address:
Chloropropanol esters are major contaminants in food, but their formation during traditional Chinese cooking remains unclear. In this study, a method based on lipase hydrolysis pretreatment was developed and validated to determine 4 chloropropanol esters. The formation of these esters during stir-frying and hotpot cooking under various conditions was investigated.
View Article and Find Full Text PDFACS Omega
October 2024
Center of Sustainable Energy and Green Materials, Faculty of Science, Mahidol University, 999 Phuttamonthon Sai 4 Rd., Salaya, Nakhon Pathom 73170, Thailand.
Int J Biol Macromol
September 2024
School of Biological Science and Technology, University of Jinan, Jinan, Shandong 250022, China. Electronic address:
Transesterification plays a crucial role in the synthesis of diverse esters in organic synthesis but is barely reported in biocatalysis. Here, we computationally identify the salicylic acid-binding protease 2 (SABP2) as an efficient ethyl ester bond synthetase by QM/MM MD and free energy simulations and present the practical and effective utilization of SABP2 as an eco-friendly biocatalyst for transesterification reactions by a series of experiments. Our findings demonstrate that SABP2 efficiently catalyzes the transesterification reaction between the carboxyl acid group of promiscuous aromatic substrates and ethanol to produce the corresponding ethyl esters.
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