Identification of the Binding Site of Chroman-4-one-Based Sirtuin 2-Selective Inhibitors using Photoaffinity Labeling in Combination with Tandem Mass Spectrometry

Abstract

Photoaffinity labeling (PAL) was used to identify the binding site of chroman-4-one-based SIRT2-selective inhibitors. The photoactive diazirine 4, a potent SIRT2 inhibitor, was subjected to detailed photochemical characterization. In PAL experiments with SIRT2, a tryptic peptide originating from the covalent attachment of photoactivated 4 was identified. The peptide covers both the active site of SIRT2 and the proposed binding site of chroman-4-one-based inhibitors. A high-power LED was used as source for the monochromatic UV light enabling rapid photoactivation.

Visible‐Light‐Promoted Cascade Radical Cyclization: Synthesis of 1,4‐Diketones Containing Chroman‐4‐One Skeletons

“…Aroyl chlorides bearing electron‐donating (‐Me, ‐OMe) and weak electron‐withdrawing (‐F, ‐Cl, ‐Br) groups could smoothly react with 2‐(allyloxy)‐benzaldehyde 2 a under the optimized conditions, giving the resulting 1,4‐diketones 3 j – m , 3 q in generally good yields. However, 4‐nitrobenzoyl chloride and 4‐cyanobenzoyl chloride did not react at all which might because of the strong electron‐withdrawing group reduce the addition susceptibility of acyl radical to C=C bonds ( 3 n and 3 o ) . In addition, a relatively low yield of the desired product was obtained when 2‐bromobenzoyl chloride was involved which could be attributed to steric effects ( 3 p , 30 %).…”

The Application of Fluorine‐Containing Reagents in Structural Proteomics

“…One way is to attach the CF 3 ‐diazirine group directly to an aromatic ring. Luthman and co‐workers developed TPD‐based probes containing a chromon‐4‐one scaffold (Figure b). They found that the CF 3 ‐diazirine motif directly replaces the chloride atom at R 1 to afford a more potent inhibitor ( 4 versus 2 ).…”

“…One key for developing ap otent TPD-based probe is to accommodate the reactive moiety or "warhead" in apharmacophore.A sT PDs have steric hinderance,t heir installation needs to be carefully considered. One way is to attach the CF 3 -diazirine group directly to an aromatic ring.L uthman and co-workers [8] developed TPD-based probes containing ac hromon-4-one scaffold (Figure 1b). They found that the CF 3 -diazirine motif directly replaces the chloride atom at R 1 to afford am ore potent inhibitor (4 versus 2).…”

Fluorierte Reagenzien in der Strukturproteomik

“…Luthman et al. entwickelten TPD‐basierte Reagenzien, die ein Chromon‐4‐on‐Gerüst enthielten (Abbildung b) . Sie beschrieben, dass der Ersatz des Chloratoms an R 1 durch das CF 3 ‐Diazirin‐Motiv zu einem potenteren Inhibitor führt ( 4 gegenüber 2 ).…”

“…Luthman et al entwickelten TPD-basierte Reagenzien, die ein Chromon-4-on-Gerüst enthielten (Abbildung 1b). [8] Sie beschrieben, dass der Ersatz des Chloratoms an R 1 durch das CF 3 -Diazirin-Motiv zu einem potenteren Inhibitor führt (4 gegenüber 2). Des Weiteren kann sogar die Wirkstoffeffizienz von der CF 3 -Diazirin-Substitution profitieren, wie an 3 zu sehen ist, bei dem der inhibitorische Effekt reduziert ist, wenn R 1 = H.…”