Benzimidazole, coumrindione and flavone derivatives as alternate UV laser desorption ionization (LDI) matrices for peptides analysis

Abstract

BackgroundMatrix-assisted laser desorption/ionization (MALDI) is a soft ionization mass spectrometric technique, allowing the analysis of bio-molecules and other macromolecules. The matrix molecules require certain characteristic features to serve in the laser desorption/ionization mechanism. Therefore, only a limited number of compounds have been identified as ultraviolet- laser desorption/ionization (UV-LDI) matrices. However, many of these routine matrices generate background signals that useful information is often lost in them. We have reported flavones, coumarindione and benzimidazole derivatives as alternate UV-LDI matrices.ResultsThirty one compounds have been successfully employed by us as matrices for the analysis of low molecular weight (LMW) peptides (up to 2000 Da). Two peptides, bradykinin and renin substrate tetra-decapeptide were analyzed by using the newly developed matrices. The MS measurements were made after mixing the matrix solution with analyte by using dried droplet sample preparation procedures. The synthesized matrix materials showed better S/N ratios and minimal background signals for low mass range. Furthermore, pico molar concentrations of [Glu1]-fibrinopeptide B human could be easily analyzed with these matrices. Finally, BSA-digest was analyzed and identified through database search against Swiss-Prot by using Mascot.ConclusionsThese results validate the good performance of the synthesized UV-laser desorption/ionization (LDI) matrices for the analysis of low molecular weight peptides.

Peptide Mass Spectra from Micrometer-Thick Ice Films Produced with Femtosecond Pulses

“… 56 , 57 However, in a typical UV-MALDI experiment, peptides are usually detected several magnitudes lower, and the signal is visible for 25 pM solution. 58 …”

“…Assuming a concentration of 10 μM and an ablation crater diameter of 20 μm, the total amount for signal generation adds up to a sensitivity of 25 attomoles, while MALDI imaging reports a sensitivity of about 500 attomoles However, in a typical UV-MALDI experiment, peptides are usually detected several magnitudes lower, and the signal is visible for 25 pM solution …”

“…56,57 However, in a typical UV-MALDI experiment, peptides are usually detected several magnitudes lower, and the signal is visible for 25 pM solution. 58 In an additional experiment, we investigated the mass limit and found that the highest obtainable mass is endothelin (2.5 kDa; Figure S18).…”

Crystal Structure Elucidation and Anticancer Studies of (-)-Pseudosemiglabrin: A Flavanone Isolated from the Aerial Parts of Tephrosia apollinea

“…The molecular mass was determined by liquid chromatography-mass spectroscopy (LC-MS) and showed a molecular ion peak at 393.11. The ultraviolet (UV) spectrum showed absorption at λ max 306, 256, (sh) and 215 nm indicating the flavone characteristics of the compound SSG [11] , [12] , [13] . The infrared (FT-IR) spectrum showed a strong and sharp vibrational band at 1740 cm −1 that indicates the presence of carbonyl (CO) moiety, more likely CO of an acetate group [14] .…”

Novel flurbiprofen clubbed oxadiazole derivatives as potential urease inhibitors and their molecular docking study

“…A number of medicinal molecules of the oxadiazole scaffold are utilized as medications in the market, including the well-known anti-hypertensive nesapidil, the strong PDF inhibitor furamizole, the HIV integrase inhibitor raltegravir, and the anti-cancer agent zibotentan. 8,9 In addition, a number of oxadiazoles have been discovered to exhibit strong monoamine oxidase inhibitory potential and to be efficacious against lipoxygenase at the nano molar level. 10…”