Quantitative LC-MS/MS analysis of azide and azidoalanine in in vitro samples following derivatisation with dansyl chloride

Abstract

An LC-MS/MS method for the simultaneous quantification of azide and azidoalanine in bacterial and mammalian cellular systems was developed to support mutagenicity evaluation of azido containing nucleoside drugs. With the aim to enhance ionization efficiency and chromatographic retention, derivatisation with dansyl chloride was optimized; study samples (diluted 1/10) were derivatised for 2 h at room temperature and subsequently analysed with reversed phase liquid chromatography in combination with electrospray mass spectrometry in the positive ion mode. Good linearity and accuracy were obtained with a lower limit of quantification of 10.0 ng mL À1 for both analytes. The method was applied in mutagenicity experiments and showed time-dependent release of azide, but no formation of azidoalanine could be detected.

A tutorial in small molecule identification via electrospray ionization‐mass spectrometry: The practical art of structural elucidation

“…The product‐ion spectrum of a derivatized azide anion from sodium azide is shown in Figure A as an example of more‐seldom observed fragmentation behavior. First, azide was derivatized with the polyaromatic sulfonamide dansyl chloride to enhance chromatographic retention and ESI efficiency . The initial loss of N 2 to form the ion at m / z 249 probably occurs via a five‐membered ring rearrangement of the sulfonamide nitrogen.…”

“…In ESI and other API sources, derivatization often aims to improve the ionization characteristics for poorly ionizable compounds. An example of such chemical derivatization strategy was mentioned in section 3, because dansyl chloride is used to improve the ionization characteristics, chromatographic retention time, and also UV/Vis response of azide (see Figure for the structure after derivatization) . Such targeted approaches assume knowledge of the presence of a certain functional group that can be derivatized.…”

“…First, azide was derivatized with the polyaromatic sulfonamide dansyl chloride to enhance chromatographic retention and ESI efficiency. 76 Figure 4A) and dansylated azide ( Figure 5A) are depicted in Figures 4B and 5B, respectively. A similar strategy can be followed for the generation of mass spectral trees after acquisition of MS n data.…”

“…An example of such chemical derivatization strategy was mentioned in section 3, because dansyl chloride is used to improve the ionization characteristics, chromatographic retention time, and also UV/Vis response of azide (see Figure 5 for the structure after derivatization). 76 Such targeted approaches assume knowledge of the presence of a certain functional group that can be derivatized. On the other hand, chemical derivatization strategies can also be exploited in structural elucidation to prove the presence of a certain specific functional group.…”

Engineered Regulon to Enable Autonomous Azide Ion Biosensing, Recombinant Protein Production, and in Vivo Glycoengineering

“…For example, zidovudine drug toxicity was shown to be closely dependent on azido group stability 14 . The current state-ofthe-art in vitro techniques involving spectrophotometry 15,16 , fluorescence [17][18][19][20] , mass spectrometry, 21,22 and redox sensing 23 have all been used for azide ion detection. However, such in vitro detection methods require extensive sample derivatization steps and are not suited for high throughput in vivo based detection of azides.…”