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Kinichi Obi - One of the best experts on this subject based on the ideXlab platform.
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TIME-OF-FLIGHT MASS SPECTROSCOPY OF Benzophenone-BENZENE AND Benzophenone-1,4-CYCLOHEXADIENE CLUSTERS USING ONE-COLOR MULTIPHOTON IONIZATION METHOD
Chemical Physics Letters, 1999Co-Authors: Toshifumi Iimori, Hironao Tanaka, Akio Kawai, Kinichi ObiAbstract:Abstract Benzophenone–benzene and Benzophenone–1,4-cyclohexadiene clusters are studied by using one-color multiphoton ionization (MPI) method with time-of-flight (TOF) mass spectroscopy. Many kinds of Benzophenone–benzene clusters are generated in the Benzophenone–benzene expansion. TOF mass spectrum in the Benzophenone–1,4-cyclohexadiene system was obtained with 270 nm laser light. The spectrum shows the ions composed of one Benzophenone ketyl radical and several 1,4-cyclohexadiene molecules. It is revealed that hydrogen abstraction reaction occurs in Benzophenone–1,4-cyclohexadiene clusters and Benzophenone ketyl radical is what REMPI process proceeds through.
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Photochemical reaction in the molecular clusters of Benzophenone with hydrogen donors formed in a supersonic free jet expansion
Journal of Photochemistry and Photobiology A: Chemistry, 1996Co-Authors: Yoshihisa Matsushita, Shogo Noguchi, Naotaka Ohiwa, Kinichi ObiAbstract:Abstract Photochemical reactions in neutral molecular clusters of Benzophenone with hydrogen donors formed in a supersonic free jet expansion have been studied. It has been found that intracluster hydrogen abstraction reaction takes place to form Benzophenone ketyl radical in the Benzophenone—1,4-cyclohexadiene mixed cluster. On the contrary, no ketyl radical has been detected when ethanol, 2-propanol, or several kinds of amine are used as a hydrogen donor. Excitation and emission spectra of the Benzophenone— N , N -dimethylaniline cluster have suggested that Benzophenone and N , N -dimethylaniline form a ground state charge transfer complex. The excitation of the Benzophenone-tri- n -butylamine cluster promotes the transformation of the van der Waals complex to an exciplex. The reactivity of the clusters on hydrogen abstraction and charge transfer reactions has been discussed on the basis of the nature of hydrogen donors.
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Hydrogen abstraction in the neutral molecular cluster of Benzophenone and hydrogen donors formed in a supersonic free jet expansion
The Journal of Physical Chemistry, 1992Co-Authors: Yoshihisa Matsushita, Yoshizumi Kajii, Kinichi ObiAbstract:This paper discusses how Benzophenone undergoes photoreduction to form Benzophenone ketyl radical by an intracellular reaction in the Benzophenone 1,4-cyclohexadiene mixed expansion in a supersonic free jet expansion. No ketyl radical fluorescence is observed when triethylamine, 2-propanol, or ethanol is the hydrogen donor; thus the normal molecular cluster activity depends on the nature of the hydrogen donor. 36 refs., 5 figs.
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Photochemical reaction of excited Benzophenone in the gas phase
The Journal of Physical Chemistry, 1992Co-Authors: Yoshihisa Matsushita, Yoshizumi Kajii, Kinichi ObiAbstract:Photochemical reactions of Benzophenone with hydrogen-donating compounds have been studied in the gas phase. It has been found that the photoreduction of excited Benzophenone proceeds to form Benzophenone ketyl radical without contributions from surrounding solvents. The quenching rate constant measurements of Benzophenone triplet have suggested that, in addition to its role in the condensed phase, the charge-transfer interaction also plays an important role in the photoreduction processof Benzophenone-amine systems in the gas phase
Yoshihisa Matsushita - One of the best experts on this subject based on the ideXlab platform.
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Photochemical reaction in the molecular clusters of Benzophenone with hydrogen donors formed in a supersonic free jet expansion
Journal of Photochemistry and Photobiology A: Chemistry, 1996Co-Authors: Yoshihisa Matsushita, Shogo Noguchi, Naotaka Ohiwa, Kinichi ObiAbstract:Abstract Photochemical reactions in neutral molecular clusters of Benzophenone with hydrogen donors formed in a supersonic free jet expansion have been studied. It has been found that intracluster hydrogen abstraction reaction takes place to form Benzophenone ketyl radical in the Benzophenone—1,4-cyclohexadiene mixed cluster. On the contrary, no ketyl radical has been detected when ethanol, 2-propanol, or several kinds of amine are used as a hydrogen donor. Excitation and emission spectra of the Benzophenone— N , N -dimethylaniline cluster have suggested that Benzophenone and N , N -dimethylaniline form a ground state charge transfer complex. The excitation of the Benzophenone-tri- n -butylamine cluster promotes the transformation of the van der Waals complex to an exciplex. The reactivity of the clusters on hydrogen abstraction and charge transfer reactions has been discussed on the basis of the nature of hydrogen donors.
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Hydrogen abstraction in the neutral molecular cluster of Benzophenone and hydrogen donors formed in a supersonic free jet expansion
The Journal of Physical Chemistry, 1992Co-Authors: Yoshihisa Matsushita, Yoshizumi Kajii, Kinichi ObiAbstract:This paper discusses how Benzophenone undergoes photoreduction to form Benzophenone ketyl radical by an intracellular reaction in the Benzophenone 1,4-cyclohexadiene mixed expansion in a supersonic free jet expansion. No ketyl radical fluorescence is observed when triethylamine, 2-propanol, or ethanol is the hydrogen donor; thus the normal molecular cluster activity depends on the nature of the hydrogen donor. 36 refs., 5 figs.
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Photochemical reaction of excited Benzophenone in the gas phase
The Journal of Physical Chemistry, 1992Co-Authors: Yoshihisa Matsushita, Yoshizumi Kajii, Kinichi ObiAbstract:Photochemical reactions of Benzophenone with hydrogen-donating compounds have been studied in the gas phase. It has been found that the photoreduction of excited Benzophenone proceeds to form Benzophenone ketyl radical without contributions from surrounding solvents. The quenching rate constant measurements of Benzophenone triplet have suggested that, in addition to its role in the condensed phase, the charge-transfer interaction also plays an important role in the photoreduction processof Benzophenone-amine systems in the gas phase
M. Grosshans - One of the best experts on this subject based on the ideXlab platform.
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Photocontact dermatitis from ketoprofen and tiaprofenic acid: cross‐reactivity study in 12 consecutive patients
Contact Dermatitis, 1998Co-Authors: Anne Bottlaender, Jean‐nicolas Scrivener, Frederic Santinelli, Ernest Heid Edouard, Bernard Cribier, M. GrosshansAbstract:The arylpropionic acid derivatives (APADs) ketoprofen and tiaprofenic acid can provoke photoallergic dermatitis. Possible cross-reactivity between APADs is of importance in patients using nonsteroidal anti-inflammatory drugs. Because of the similarities in chemical structures, we investigated patients with photoallergy to ketoprofen or tiaprofenic acid, in order to study cross-reactivity between APADs and a possible pattern of cross-reactivity between Benzophenone-containing molecules, so as to determine the molecular basis of photoallergy to ketoprofen or tiaprofenic acid. 10 patients with photoallergy to topical ketoprofen, 2 with photoallergy to oral tiaprofenic acid, and 15 control subjects with no history of contact dermatitis from APADs, nor from Benzophenone-containing molecules, were photopatch tested in triplicate with ketoprofen, tiaprofenic acid, other APADs (alminoprofen, fenoprofen, flurbiprofen, ibuprofen and naproxen), Benzophenone-containing molecules (fenofibrate, oxybenzone, sulisobenzone), and unsubstituted Benzophenone. 1 set was irradiated with UVA light, 1 with solar-simulated irradiation and 1 dark control. Tests were read at 2, 3 and 4 days. Patients reacted to both ketoprofen and tiaprofenic acid (12/12), fenofibrate (8/12), oxybenzone (3/12) and unsubstituted Benzophenone (11/12), but not to other APADs, nor to sulisobenzone. Tests remained negative in control patients. Photoallergy is due to the Benzophenone moiety of ketoprofen, or to the very similar thiophene-phenylketone of tiaprofenic acid, but not to their arylpropionic function. This induces cross-reactivity to fenofibrate and oxybenzone but not to APADs without a Benzophenone moiety, which may therefore probably be used in such patients. Unsubstituted Benzophenone should be added to standard phototesting series.
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photocontact dermatitis from ketoprofen and tiaprofenic acid cross reactivity study in 12 consecutive patients
Contact Dermatitis, 1998Co-Authors: Anne Bottlaender, Jean‐nicolas Scrivener, Frederic Santinelli, Ernest Heid Edouard, Bernard Cribier, M. GrosshansAbstract:The arylpropionic acid derivatives (APADs) ketoprofen and tiaprofenic acid can provoke photoallergic dermatitis. Possible cross-reactivity between APADs is of importance in patients using nonsteroidal anti-inflammatory drugs. Because of the similarities in chemical structures, we investigated patients with photoallergy to ketoprofen or tiaprofenic acid, in order to study cross-reactivity between APADs and a possible pattern of cross-reactivity between Benzophenone-containing molecules, so as to determine the molecular basis of photoallergy to ketoprofen or tiaprofenic acid. 10 patients with photoallergy to topical ketoprofen, 2 with photoallergy to oral tiaprofenic acid, and 15 control subjects with no history of contact dermatitis from APADs, nor from Benzophenone-containing molecules, were photopatch tested in triplicate with ketoprofen, tiaprofenic acid, other APADs (alminoprofen, fenoprofen, flurbiprofen, ibuprofen and naproxen), Benzophenone-containing molecules (fenofibrate, oxybenzone, sulisobenzone), and unsubstituted Benzophenone. 1 set was irradiated with UVA light, 1 with solar-simulated irradiation and 1 dark control. Tests were read at 2, 3 and 4 days. Patients reacted to both ketoprofen and tiaprofenic acid (12/12), fenofibrate (8/12), oxybenzone (3/12) and unsubstituted Benzophenone (11/12), but not to other APADs, nor to sulisobenzone. Tests remained negative in control patients. Photoallergy is due to the Benzophenone moiety of ketoprofen, or to the very similar thiophene-phenylketone of tiaprofenic acid, but not to their arylpropionic function. This induces cross-reactivity to fenofibrate and oxybenzone but not to APADs without a Benzophenone moiety, which may therefore probably be used in such patients. Unsubstituted Benzophenone should be added to standard phototesting series.
Anne Bottlaender - One of the best experts on this subject based on the ideXlab platform.
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Photocontact dermatitis from ketoprofen and tiaprofenic acid: cross‐reactivity study in 12 consecutive patients
Contact Dermatitis, 1998Co-Authors: Anne Bottlaender, Jean‐nicolas Scrivener, Frederic Santinelli, Ernest Heid Edouard, Bernard Cribier, M. GrosshansAbstract:The arylpropionic acid derivatives (APADs) ketoprofen and tiaprofenic acid can provoke photoallergic dermatitis. Possible cross-reactivity between APADs is of importance in patients using nonsteroidal anti-inflammatory drugs. Because of the similarities in chemical structures, we investigated patients with photoallergy to ketoprofen or tiaprofenic acid, in order to study cross-reactivity between APADs and a possible pattern of cross-reactivity between Benzophenone-containing molecules, so as to determine the molecular basis of photoallergy to ketoprofen or tiaprofenic acid. 10 patients with photoallergy to topical ketoprofen, 2 with photoallergy to oral tiaprofenic acid, and 15 control subjects with no history of contact dermatitis from APADs, nor from Benzophenone-containing molecules, were photopatch tested in triplicate with ketoprofen, tiaprofenic acid, other APADs (alminoprofen, fenoprofen, flurbiprofen, ibuprofen and naproxen), Benzophenone-containing molecules (fenofibrate, oxybenzone, sulisobenzone), and unsubstituted Benzophenone. 1 set was irradiated with UVA light, 1 with solar-simulated irradiation and 1 dark control. Tests were read at 2, 3 and 4 days. Patients reacted to both ketoprofen and tiaprofenic acid (12/12), fenofibrate (8/12), oxybenzone (3/12) and unsubstituted Benzophenone (11/12), but not to other APADs, nor to sulisobenzone. Tests remained negative in control patients. Photoallergy is due to the Benzophenone moiety of ketoprofen, or to the very similar thiophene-phenylketone of tiaprofenic acid, but not to their arylpropionic function. This induces cross-reactivity to fenofibrate and oxybenzone but not to APADs without a Benzophenone moiety, which may therefore probably be used in such patients. Unsubstituted Benzophenone should be added to standard phototesting series.
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photocontact dermatitis from ketoprofen and tiaprofenic acid cross reactivity study in 12 consecutive patients
Contact Dermatitis, 1998Co-Authors: Anne Bottlaender, Jean‐nicolas Scrivener, Frederic Santinelli, Ernest Heid Edouard, Bernard Cribier, M. GrosshansAbstract:The arylpropionic acid derivatives (APADs) ketoprofen and tiaprofenic acid can provoke photoallergic dermatitis. Possible cross-reactivity between APADs is of importance in patients using nonsteroidal anti-inflammatory drugs. Because of the similarities in chemical structures, we investigated patients with photoallergy to ketoprofen or tiaprofenic acid, in order to study cross-reactivity between APADs and a possible pattern of cross-reactivity between Benzophenone-containing molecules, so as to determine the molecular basis of photoallergy to ketoprofen or tiaprofenic acid. 10 patients with photoallergy to topical ketoprofen, 2 with photoallergy to oral tiaprofenic acid, and 15 control subjects with no history of contact dermatitis from APADs, nor from Benzophenone-containing molecules, were photopatch tested in triplicate with ketoprofen, tiaprofenic acid, other APADs (alminoprofen, fenoprofen, flurbiprofen, ibuprofen and naproxen), Benzophenone-containing molecules (fenofibrate, oxybenzone, sulisobenzone), and unsubstituted Benzophenone. 1 set was irradiated with UVA light, 1 with solar-simulated irradiation and 1 dark control. Tests were read at 2, 3 and 4 days. Patients reacted to both ketoprofen and tiaprofenic acid (12/12), fenofibrate (8/12), oxybenzone (3/12) and unsubstituted Benzophenone (11/12), but not to other APADs, nor to sulisobenzone. Tests remained negative in control patients. Photoallergy is due to the Benzophenone moiety of ketoprofen, or to the very similar thiophene-phenylketone of tiaprofenic acid, but not to their arylpropionic function. This induces cross-reactivity to fenofibrate and oxybenzone but not to APADs without a Benzophenone moiety, which may therefore probably be used in such patients. Unsubstituted Benzophenone should be added to standard phototesting series.
Ernest Heid Edouard - One of the best experts on this subject based on the ideXlab platform.
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Photocontact dermatitis from ketoprofen and tiaprofenic acid: cross‐reactivity study in 12 consecutive patients
Contact Dermatitis, 1998Co-Authors: Anne Bottlaender, Jean‐nicolas Scrivener, Frederic Santinelli, Ernest Heid Edouard, Bernard Cribier, M. GrosshansAbstract:The arylpropionic acid derivatives (APADs) ketoprofen and tiaprofenic acid can provoke photoallergic dermatitis. Possible cross-reactivity between APADs is of importance in patients using nonsteroidal anti-inflammatory drugs. Because of the similarities in chemical structures, we investigated patients with photoallergy to ketoprofen or tiaprofenic acid, in order to study cross-reactivity between APADs and a possible pattern of cross-reactivity between Benzophenone-containing molecules, so as to determine the molecular basis of photoallergy to ketoprofen or tiaprofenic acid. 10 patients with photoallergy to topical ketoprofen, 2 with photoallergy to oral tiaprofenic acid, and 15 control subjects with no history of contact dermatitis from APADs, nor from Benzophenone-containing molecules, were photopatch tested in triplicate with ketoprofen, tiaprofenic acid, other APADs (alminoprofen, fenoprofen, flurbiprofen, ibuprofen and naproxen), Benzophenone-containing molecules (fenofibrate, oxybenzone, sulisobenzone), and unsubstituted Benzophenone. 1 set was irradiated with UVA light, 1 with solar-simulated irradiation and 1 dark control. Tests were read at 2, 3 and 4 days. Patients reacted to both ketoprofen and tiaprofenic acid (12/12), fenofibrate (8/12), oxybenzone (3/12) and unsubstituted Benzophenone (11/12), but not to other APADs, nor to sulisobenzone. Tests remained negative in control patients. Photoallergy is due to the Benzophenone moiety of ketoprofen, or to the very similar thiophene-phenylketone of tiaprofenic acid, but not to their arylpropionic function. This induces cross-reactivity to fenofibrate and oxybenzone but not to APADs without a Benzophenone moiety, which may therefore probably be used in such patients. Unsubstituted Benzophenone should be added to standard phototesting series.
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photocontact dermatitis from ketoprofen and tiaprofenic acid cross reactivity study in 12 consecutive patients
Contact Dermatitis, 1998Co-Authors: Anne Bottlaender, Jean‐nicolas Scrivener, Frederic Santinelli, Ernest Heid Edouard, Bernard Cribier, M. GrosshansAbstract:The arylpropionic acid derivatives (APADs) ketoprofen and tiaprofenic acid can provoke photoallergic dermatitis. Possible cross-reactivity between APADs is of importance in patients using nonsteroidal anti-inflammatory drugs. Because of the similarities in chemical structures, we investigated patients with photoallergy to ketoprofen or tiaprofenic acid, in order to study cross-reactivity between APADs and a possible pattern of cross-reactivity between Benzophenone-containing molecules, so as to determine the molecular basis of photoallergy to ketoprofen or tiaprofenic acid. 10 patients with photoallergy to topical ketoprofen, 2 with photoallergy to oral tiaprofenic acid, and 15 control subjects with no history of contact dermatitis from APADs, nor from Benzophenone-containing molecules, were photopatch tested in triplicate with ketoprofen, tiaprofenic acid, other APADs (alminoprofen, fenoprofen, flurbiprofen, ibuprofen and naproxen), Benzophenone-containing molecules (fenofibrate, oxybenzone, sulisobenzone), and unsubstituted Benzophenone. 1 set was irradiated with UVA light, 1 with solar-simulated irradiation and 1 dark control. Tests were read at 2, 3 and 4 days. Patients reacted to both ketoprofen and tiaprofenic acid (12/12), fenofibrate (8/12), oxybenzone (3/12) and unsubstituted Benzophenone (11/12), but not to other APADs, nor to sulisobenzone. Tests remained negative in control patients. Photoallergy is due to the Benzophenone moiety of ketoprofen, or to the very similar thiophene-phenylketone of tiaprofenic acid, but not to their arylpropionic function. This induces cross-reactivity to fenofibrate and oxybenzone but not to APADs without a Benzophenone moiety, which may therefore probably be used in such patients. Unsubstituted Benzophenone should be added to standard phototesting series.