The Effect of Structural Variation on the Hydrolysis of Δ²-Thiazolines

Yersiniabactin from Yersinia pestis: biochemical characterization of the siderophore and its role in iron transport and regulation

“…1). These were pK, = 3.10 (aliphatic-substituted thiazoline) ; pK, = 3.12 (phenyl-substituted thiazoline) (Schmir, 1965) ; pK, = 4.80 (carboxylic acid) ; pK, = 9.89 (phenol) (Bird & Cheeseman, 1984); pK, = 11.3 (thiazolidine) (Schmir, 1965) ; and pK, = 16 (secondary alcohol) (Bordwell, 1963), which was assumed to be protonated in the calculation. A similar calculation was performed for EDTA using pK values of 2.0,2.7,6-2 and 10.3 (Dawson et al, 1987).…”

Reactions of cysteamine and other amine metabolites with glyoxylate and oxygen catalyzed by mammalian D-amino acid oxidase.

“…coo N IX Consistent with this is the observation that the product from the cysteamine reaction absorbs strongly at 270 nm (19). From the known reactivity of related compounds, it is expected that such products will be very susceptible to hydrolysis and attack by nucleophiles, especially when X = S (19)(20)(21). Given (26).…”

“…To us, the most likely possibility is that the product of the reaction is a metabolic effector. It might act as a reversible effector of some enzymic reactions like cyclic AMP does, but, given the known high reactivity of thiazolines toward nucleophiles (19)(20)(21), it seems more likely that the product would react (Eq. 4) with a nucleophilic group on some (700- (44)(45)(46) of cysteamine to those of glyoxylate (47), but also it links them to the known effects of metabolites and drugs on D-AA oxidase reactions.…”

Post translational modifications of Trifolitoxin: a blue fluorescent peptide antibiotic

“…Below pH 5.0 biological activity declined rapidly to about two percent or less of the original activity as the thiazoline ring opened. According to Schmir [ 44 ] Δ 2 -thiazolines hydrate at low pH to form a pseudobase which is in equilibrium with the ring open species and therefore it was possible to estimate hydration constant for the TFX thiazoline ring by spectroscopic method, pK H 2.61 ± 0.05. Four lines of evidence support the notion that the cysteine in TFX is cyclized to form a thiazoline ring.…”