De novogeneration of a bright blue fluorophore from 2-oxoglutarate in biological samples

Abstract

DTPP, a bright fluorophore with 2-pyridone and γ-lactam, is generated in a de novo manner from non-fluorogenic 2-oxoglutarate and specific amines. The DTPP-based fluorometry is applied to the analysis of 2-oxoglutarate in a biological sample.

Design of 2‐Pyridone Fluorophores for Brighter Emissions at Longer Wavelengths

“…In our previous study, the introduction of an amide substituent at the C 4 position of the 2-pyridone core significantly enhanced the fluorescence quantum yield. [6] Accordingly, we initially compared the fluorescence of derivatives with an ester or amide substituent at the C 4 position of 2-pyridone (Figure S1). Because the ester derivatives showed stronger fluorescence than their amide analogs, we focused on ester derivatives for subsequent studies (Figure 1a).…”

“…The authors have cited additional references within the Supporting Information. [6,8,[12][13][14][15][19][20][21]…”

“…Our group recently discovered that a 2-pyridonebased blue fluorophore 3,3'-(2,5-bis(2-(diethylamino)ethyl)-1,6dioxo-2,3,5,6-tetrahydro-1H-pyrrolo [3,4-c]pyridine-3,7diyl)dipropionic acid (DTPP) could be spontaneously produced from 2-oxoglutarate and amines under mild conditions (Scheme 1a). [6] While the 2-pyridone core is barely fluorescent (� F < 0.1 %), it emits strong fluorescence with a high quantum yield (� F > 75 %) when fused with a lactam ring. Because the parent DTPP system showed limitations in the light absorption (ɛ = 3,000-4,000 M À 1 cm À 1 ) and emission wavelengths (λ em = 400-415 nm) for practical applications, we envisioned that the photophysical properties of 2-pyridone-based fluorophores could be further improved by understanding and leveraging the structure-fluorescence relationship (SFR).…”