Dansyl and Dabsyl Analytical Constructs as Tools for the Accurate Estimation of Compounds in Solid-Phase Synthesis

Abstract

The presence of dansyl or dabsyl chromogenic moieties in a solid-phase analytical construct, an assembly of linkers/spacers/sensitizers for improving analytical characterization, allows the accurate estimation of products from solid-phase synthesis by UV detection during liquid chromatography-mass spectrometry analysis in the cleavage solution. The spectroscopic properties of dansylated molecules have been evaluated to verify the "compound-independent UV absorption" necessary for using the chromophore in the accurate estimation. First, measurements on commercial dansylated compounds were made, then a series of construct-like molecules were prepared by solution-phase synthetic procedures and their UV properties were determined. Compound calibration curves were determined, and UV absorption was shown to be both proportional to the compound concentration and compound-independent. An example of a dansyl construct derivative was then prepared on a polymeric matrix, and an accurate estimation using the calibration curves was carried out in the cleavage solution. Good agreement was found between the calculated amount of released compound using the UV calibration curves and the calculated amount using both (1)H NMR and LC/chemiluminescent nitrogen detection quantitative techniques. Preliminary studies using the dabsyl moiety as an improved chromophore with higher wavelength and extinction coefficient are also reported.

Discovery and Characterization of Catalysts for Azide−Alkyne Cycloaddition by Fluorescence Quenching

“…6 The effect is easily visualized by eye under longwavelength ultraviolet illumination or quantitated by fluorescence spectroscopy. Screening of candidate ligands in parallel format was done first by simple visual imaging, which offers a rapid readout with simultaneous evaluation of control reactions.…”

Recent Advances in Analytical Construct Resins

“…The use of an alternative chromophoric construct was adopted by Paio who reported the use of dansyl (28) and dabsyl (29) constructs as effective chromophores for the quantification of compounds in solid-phase chemistry; (Scheme 11) [30]. The dansyl moiety absorbed at a distinguishable wavelength (339 nm) and contained a pendant tertiary amine that sensitised analytical fragment (30) to ESI MS.…”

A synthesis of new, bi-labeled peptides for quantitative proteomics

“…Such peptides can be used as internal references when assessing the concentration of a sample by mass spectrometry, for example, using multiple reaction monitoring (MRM) method [2,3]. The following stable isotopes: 2 H, 13 C, 15 N, and 18 O are often used for this purpose [1,4,5]. Labeling with 18 O has several significant advantages over the other isotopes.…”

“…They can be divided into two main categories: enzymatic [7,8] and acid-catalyzed [9][10][11]. Isotopically labeled peptides may be also obtained using commercially available amino acid derivatives containing 13 C or 15 N atoms. Therefore, from synthetic point of view, the preparation of labeled peptides does not pose a problem.…”

“…We have, therefore, decided to develop an approach based on the concept of analytical construct [15,16]. This term was introduced by Geysen et al [17].…”