Assessment of the effects of repeated freeze thawing and extended bench top processing of plasma samples using untargeted metabolomics was written by Goodman, Kelli;Mitchell, Matthew;Evans, Anne M.;Miller, Luke A. D.;Ford, Lisa;Wittmann, Bryan;Kennedy, Adam D.;Toal, Douglas. And the article was included in Metabolomics in 2021.Reference of 444-27-9 This article mentions the following:
Introduction: Clin. metabolomics has utility as a screen for inborn errors of metabolism (IEM) and variant classification in patients with rare disease. It is important to understand and characterize preanal. factors that influence assay performance during patient sample testing. Objectives: To evaluate the impact of extended thawing of human EDTA plasma samples on ice prior to extraction as well as repeated freeze-thaw cycling of samples to identify compounds that are unstable prior to metabolomic anal. Twenty-four (24) donor EDTA plasma samples were collected and immediately frozen at – 80 °C. Twelve samples were thawed on ice and extracted for anal. at time 0, 2, 4, and 6 h. Twelve other donor samples were repeatedly thawed and frozen up to four times and analyzed at each cycle. Compound levels at each time point/freeze-thaw cycle were compared to the control samples using matched-paired t tests to identify analytes affected by each condition. We identified 1026 biochems. across all samples. Incubation of thawed EDTA plasma samples on ice for up to 6 h resulted in < 1% of biochems. changing significantly. Freeze-thaw cycles affected a greater percentage of the metabolome; ∼ 2% of biochems. changed after 3 freeze-thaw cycles. Our study highlights that the number and magnitude of these changes are not as widespread as other aspects of improper sample handling. In total, < 3% of the metabolome detected on our clin. metabolomics platform should be disqualified when multiple freeze-thaw cycles or extended thawing at 4 °C are performed on a given sample. In the experiment, the researchers used many compounds, for example, Thiazolidine-4-carboxylic acid (cas: 444-27-9Reference of 444-27-9).
Thiazolidine-4-carboxylic acid (cas: 444-27-9) belongs to thiazolidine derivatives. In the thiazolidine nucleus, a large number of substitutions are possible on 2, 4 and 5 positions responsible for enhancing the compound’s pharmaceutical importance. In addition, the use of thiazolidines as an inhibitor of tyrosyl-DNA phosphodiesterase Iand influenza neuraminidase, pro-drugs for the treatment of cystinosis, radioprotective against γ-irradiation and as S1P1 receptor agonist has also been reported.Reference of 444-27-9
Referemce:
Thiazolidine – Wikipedia,
Thiazolidine – ScienceDirect.com