TY - JOUR

T1 - New insights into the nature of short-lived paramagnetic intermediates of ketoprofen. Photo-CIDNP study

AU - Babenko, Simon V.

AU - Kuznetsova, Polina S.

AU - Polyakov, Nikolay E.

AU - Kruppa, Aleksandr I.

AU - Leshina, Tatyana V.

PY - 2020/4/1

Y1 - 2020/4/1

N2 - The short-lived paramagnetic particles formed during the UV irradiation of nonsteroidal anti-inflammatory drug - ketoprofen (KP) have been investigated using chemically induced dynamic nuclear polarization (CIDNP). This study answers the questions about the nature of paramagnetic particles which can be responsible for KP phototoxic effects. Phototoxic side effects of NSAIDs, according modern point of view, are associated with the action of free radicals, however, there is insufficient information regarding the nature of the radical species. In contrast, most ketoprofen photodegradation schemes include carbanion as a precursor of products. CIDNP effects analysis has shown that all the major products of KP photodegradation can form via radical pairs (RPs) involving benzyl (2′), ketyl (3′) and CO2H[rad] or CO2 − [rad] free radicals and solvated electron. Radical ways of KP photodegradation include: decarboxylation via RP with benzyl radical formation (I) in non-aqueous solution and both, (I) and photoreduction with formation of ketyl radicals in the presence of water. Moreover, it was found that the photoinduced radical decarboxylation of KP represents a reversible process.

AB - The short-lived paramagnetic particles formed during the UV irradiation of nonsteroidal anti-inflammatory drug - ketoprofen (KP) have been investigated using chemically induced dynamic nuclear polarization (CIDNP). This study answers the questions about the nature of paramagnetic particles which can be responsible for KP phototoxic effects. Phototoxic side effects of NSAIDs, according modern point of view, are associated with the action of free radicals, however, there is insufficient information regarding the nature of the radical species. In contrast, most ketoprofen photodegradation schemes include carbanion as a precursor of products. CIDNP effects analysis has shown that all the major products of KP photodegradation can form via radical pairs (RPs) involving benzyl (2′), ketyl (3′) and CO2H[rad] or CO2 − [rad] free radicals and solvated electron. Radical ways of KP photodegradation include: decarboxylation via RP with benzyl radical formation (I) in non-aqueous solution and both, (I) and photoreduction with formation of ketyl radicals in the presence of water. Moreover, it was found that the photoinduced radical decarboxylation of KP represents a reversible process.

KW - CIDNP

KW - Decarboxylation

KW - Free radicals

KW - Ketoprofen

KW - ELECTRON-SPIN-RESONANCE

KW - ACID

KW - MECHANISM

KW - WATER-RICH

KW - PHOTOSENSITIVITY

KW - RESOLVED RESONANCE RAMAN

KW - BENZOPHENONE

KW - PHOTOCHEMISTRY

KW - HYDROGEN-PEROXIDE

KW - PHOTODECARBOXYLATION

UR - http://www.scopus.com/inward/record.url?scp=85078159689&partnerID=8YFLogxK

U2 - 10.1016/j.jphotochem.2020.112383

DO - 10.1016/j.jphotochem.2020.112383

M3 - Article

AN - SCOPUS:85078159689

VL - 392

JO - Journal of Photochemistry and Photobiology A: Chemistry

JF - Journal of Photochemistry and Photobiology A: Chemistry

SN - 1010-6030

M1 - 112383

ER -