Novel derivatization with Sanger's reagent (2,4-dinitrofluorobenzene [DNFB]) and related methodological developments for improved detection of amphetamine enantiomers by circular dichroism spectroscopy

Abstract

Abstract.A new analytical procedure based on the derivatization of amphetamine with Sanger's reagent (2,4-dinitrofluorobenzene) and a subsequent circular dichroism spectroscopic analysis are proposed for the determination of amphetamine enantiomers. The main advantage of the approach is the fact that the new synthetized derivative can be detected in the visible wavelength region with significantly better sensitivity than the original amphetamine. This allows a reliable determination of the optical isomers of the amphetamine without the need of separation from some of the most frequently occurring additives such as caffeine and lactose in the case of illicit drugs, or auxiliary materials in the case of legal amphetamine containing preparations.

Total Biosynthesis of Triacsin Featuring an N-hydroxytriazene Pharmacophore

“…Specifically, N 6 -hydroxy-lysine (7) that is generated by Tri26 (an N-hydroxylase homolog), reacts with glycine, promoted by Tri28 (a cupin and metRS didomain protein), to form N6-(carboxymethylamino)lysine (8), which then undergoes an oxidative cleavage to yield HAA and 2-aminoadipate 6-semialdehyde catalyzed by Tri27, an FAD-dependent Damino acid oxidase homolog. The Tri26-28 coupled biochemical assay successfully produced HAA by comparing to an authentic standard through 2,4-dinitrofluorobenzene (DNFB) derivatization 17,25 , confirming the predicted activity of Tri26-28 (Fig. 3a, Supplementary Fig.…”

“…The copyright holder for this preprint (which this version posted May 13, 2021. ; https://doi.org/10.1101/2021.05.12.443849 doi: bioRxiv preprint pH 7.5, 1 mM lysine, 1 mM glycine, mM NADPH, 0.2 mM FAD, 5 mM ATP, mM MgCl2, μM Tri26, μM Tri27, and μM Tri20. The DNFB derivatization method was adapted from a previous work 25 . The reaction was then derivatized with μL of 1 mM of DNFB dissolved in 200 mM borate pH 9.0 and incubated for mins at 60 °C.…”

Biological monitoring of occupational exposure to 5-fluorouracil: Urinary α-fluoro-β-alanine assay by high performance liquid chromatography tandem mass spectrometry in health care personnel

“…2. The derivative solution remained stable for at least 1 week at 5 • C in darkness [24,25], and derivatization at 65 • C for 30 min resulted in total conversion. Furthermore, this reaction proceeded in an aqueous solution, which is highly desirable when analysing a biological sample.…”

Sensitivity improvement of circular dichroism detection in HPLC by using a low‐pass electronic noise filter: Application to the enantiomeric determination purity of a basic drug

“…27 However, in most cases, the derivatization reaction is not quantitative and secondary products may be generated. Another easy way to improve sensitivity and detection limits is to apply low-pass electronic noise filtering of the CD signal.…”

“…To overcome the sensitivity lack, chemical derivatization can be performed by applying a chromophore reactant on the solute to form a stable product with higher CD ellipticity. 27 However, in most cases, the derivatization reaction is not quantitative and secondary products may be generated. Another easy way to improve sensitivity and detection limits is to apply low-pass electronic noise filtering of the CD signal.…”