Aromatic aldehydes as selective fluorogenic derivatizing agents for α‐dicarbonyl compounds. Application to HPLC analysis of some advanced glycation end products and oxidative stress biomarkers in human serum

Abstract

α-Dicarbonyl compounds (α-DCs) are very clinically important as they are considered as advanced glycation end products (AGEs) precursors and biomarkers for many chronic diseases such as diabetes and vascular diseases, in addition to their major role in progression of complications of such diseases. Aromatic aldehydes and ammonium acetate were productively used as a one-pot co-reagents for fluorogenic derivatization of α-DCs yielding fluorescent imidazole derivatives. Among the tried aromatic aldehydes, 4-carbomethoxybenzaldehyde yielded the products with best fluorescent characters. This approach for fluorogenic derivatization of α-DCs overcome the selectivity problem of the most commonly used derivatization reagent for α-DCs, α-diamino compounds, that can react unselectively with α-DCs and aldehydes. Separation of the formed imidazole derivatives of five α-DCs including glucosone, 3-deoxyglucosone, glyoxal, methyl glyoxal and dimethyl glyoxal together with ethylmethylglyoxal as an internal standard was carried out on an octyl column using a mobile phase consisted of methanol-water (15:85, v/v%) containing 0.2% formic acid with time programed flow, followed by fluorescence detection at excitation/emission wavelengths of 310/410 nm. The method showed excellent sensitivity for the targeted α-DCs with limits of detections ranging from 0.4 to 5.0 nM in human serum. Simple protein precipitation procedure was used for human serum treatment yielding very good recovery (91-105%) for the targeted α-DCs. The developed method was fully validated, then applied to the analysis of the five above mentioned clinically important α-DCs in serum samples of healthy, diabetic, rheumatic and cardiac disorders human volunteers. Due to the excellent analytical features of the developed method, including high selectivity and sensitivity, it was able to detect the pattern of the targeted α-DCs serum levels under the investigated different clinical conditions.

Current trends in isotope‐coded derivatization liquid chromatographic‐mass spectrometric analyses with special emphasis on their biomedical application

“…Their derivatization reaction depends on the coupling of aldehydes with an alpha‐dicarbonyl compound and ammonium acetate to form a fluorescence and strongly ionizable imidazole derivative. This derivatization technique was applied for determination of various types of aldehydes and alpha carbonyl aldehydes in biological samples (El‐Maghrabey, Kishikawa, & Kuroda, ; El‐Maghrabey, Kishikawa, Ohyama, & Kuroda, ; El‐Maghrabey, Nakatani, Kishikawa, & Kuroda, ; Fathy Bakr Ali et al, ). Recently, a novel ICD method for aldehydes was developed by the same research group based on the same idea using commercially available 15 N 0 / 15 N 1 ‐ammonium acetate and 9,10‐phenanthrenequinone.…”

“…DAPB, 3-(dimethylaminophenyl)-dihydroxyborane; DMBA, 4-(dimethylamino)-benzoic acid; ICD, isotope-coded derivatization; MCR6G, 3-N-methyl-2 0 -carboxyl rhodamine 6G; PAMBA, 4-phenylaminomethylbenzeneboric acid. Kuroda, 2016;El-Maghrabey, Kishikawa, Ohyama, & Kuroda, 2014; El-Maghrabey, Nakatani, Kishikawa, & Kuroda, 2018b;Fathy Bakr Ali et al, 2013). Recently, a novel ICD method for aldehydes was developed by the same research group based on the same idea using commercially available 15 N 0 / 15 N 1 -ammonium acetate and 9,10-phenanthrenequinone.…”

A highly sensitive micelle‐enhanced synchronous spectrofluorimetric determination of the recently approved co‐formulated drugs, bilastine and montelukast in pharmaceuticals and human plasma at nanogram levels

“…Therefore, the spectrofluorimetric technique was widely applied for the determination of many pharmaceutical compounds in their dosage forms or biological fluids [14][15][16][17][18][19][20][21][22][23][24][25]. Superior sensitivity and selectivity are the hallmarks of the spectrofluorimetric approach [13,26,27].…”

“…Therefore, the spectrofluorimetric technique was widely applied for the determination of many pharmaceutical compounds in their dosage forms or biological fluids [14–25]. Superior sensitivity and selectivity are the hallmarks of the spectrofluorimetric approach [13, 26, 27]. However, synchronous fluorescence spectroscopy (SFS) mode must be used when examining mixtures with overlapping spectra.…”

Diagnosis of methylglyoxal in blood by using far-infrared spectroscopy and o-phenylenediamine derivation

“…These methods mainly depend on MGO separation by chromatography technique. However, their disadvantages, including expensive instruments, complicated operation flow, and long processing-time, determine these methods are not suitable for routine clinical use [23,24]. There is no clinical method for MGO identification in blood now.…”