Photosensitisation with naphthoquinones and binaphthoquinones: EPR spin trapping and optical studies-formation of semiquinone radical and reactive oxygen species on photoillumination

Mothilal, K.K.; Inbaraj, Johnson J.; Chignell, Colin F.; Gandhidasan, R.; Murugesan, Ramachandran

doi:10.1016/j.jphotochem.2003.11.007

Cited by 10 publications

(3 citation statements)

References 24 publications

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“…The constituents of this extract were separated by flash chromatography, OPLC and preparative TLC. A new naphthyl derivative, 4-hydroxy-5,6-dimethoxy-2-naphthaldehyde ( 1 ), and a triterpene, Δ 12,13 -20,29-dihydrobetulin ( 2 ) were isolated from a natural source for the first time, along with nine known compounds: 7-methyl-juglone ( 3 ) [16], diospyrin ( 4 ) [17], isodiospyrin ( 5 ) [16–18], shinanolone ( 6 ) [19], lupeol ( 7 ) [20], betulin ( 8 ) [21], betulinic acid ( 9 ) [22], betulinaldehyde ( 10 ) [23], and ursolic acid ( 11 ) [24]. Although they are common in most of the Ebenaceae family [5], compounds 10 and 11 were isolated for the first time from D. virginiana .…”

Section: Resultsmentioning

confidence: 99%

Antifungal Metabolites from the Roots of Diospyros virginiana by Overpressure Layer Chromatography

Wang

Habib

León

et al. 2011

Chemistry & Biodiversity

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A preparative overpressure layer chromatography (OPLC) method was successfully used for the separation of two new natural compounds, 4-hydroxy-5,6-dimethoxy-2-naphthaldehyde (1) and Δ12,13-20,29-dihydrobetulin (2) together with nine known compounds including 7-methyl-juglone (3), diospyrin (4), isodiospyrin (5), shinanolone (6), lupeol (7), betulin (8), betulinic acid (9), betulinaldehyde (10), and ursolic acid (11) from the acetone extract of the roots of Diospyros virginiana. Their identification was performed with mono and bidimensional NMR spectroscopy and HR-ESI-MS methods. All the isolated compounds were evaluated for their antifungal activity against Colletotrichum fragariae, C. gloeosporioides, C. acutatum, Botrytis cinerea, Fusarium oxysporum, Phomopsis obscurans, and P. viticola using in vitro micro-dilution broth assay. The results indicated that compounds 3 and 5 showed high antifungal activity against P. obscurans at 30 μM with 97.0 % and 81.4 % growth inhibition and moderate activity against P. viticola (54.3 % and 36.6 %). It appears that an optimized OPLC system offers a rapid and efficient method of exploiting bioactive natural products.

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Section: Resultsmentioning

confidence: 99%

Antifungal Metabolites from the Roots of Diospyros virginiana by Overpressure Layer Chromatography

Wang

Habib

León

et al. 2011

Chemistry & Biodiversity

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“…The photosensitizer (S) absorbs light to become a singlet-excited state ( 1 S), which is rapidly converted into its [31].…”

Section: Confirmation Of Ros Generated From Photochemical Reactionmentioning

confidence: 99%

An ultrasensitive and highly selective determination method for quinones by high-performance liquid chromatography with photochemically initiated luminol chemiluminescence

Ahmed

Kishikawa

Ohyama

et al. 2009

Journal of Chromatography A

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Quinones are a class of compounds of substantial toxicological and pharmacological interest. An ultrasensitive and highly selective chemiluminescence (CL) method was newly developed for the determination of quinones based on the utility of photochemically initiated luminol CL. The method involves ultraviolet (UV) irradiation of quinones to generate reactive oxygen species (ROS) through the unique photosensitization reaction accompanied with the photolytical generation of 3,6-dihydroxyphthalic acid (DHPA) from quinones. The photoproducts were detected by luminol CL reaction. Interestingly, it was noticed that DHPA had enhancement effect for the luminol CL. The generation of the enhancer (DHPA) in association with the oxidant (ROS) in the photochemical reaction greatly increases the sensitivity and selectivity of the proposed luminol CL method. In order to elucidate the type of ROS produced by the photosensitizaion reaction in relation to the proposed CL reaction, we investigated the quenching effect of selective ROS scavengers in the luminol CL. Although several ROS were generated, superoxide anion was the most effective ROS for the generated CL. Moreover, the enhancement mechanism of DHPA for luminol CL was confirmed. The enhancement was found to be through the formation of stabilized semiquinone anion radical that provided long-lived CL. The generation of the semiquinone radical was confirmed by electron spin resonance technique. Furthermore, we developed an HPLC method with on-line photochemical reaction followed by the proposed CL detection for the determination of four quinones. A luminol analogue, L-012, was used for its high sensitivity. The detection limits for quinones obtained with the proposed method (S/N=3) were in the range 1.5-24 fmol that were 10-1000 times more sensitive compared with the previous methods. Finally, the developed HPLC-CL system was successfully applied for the determination of quinones in airborne particulate samples collected at Nagasaki city.

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“…O 1 O 2 pode ser formado pela reação do HOCl com H 2 O 2 , sendo que a formação intracelular deste composto tem sido demonstrada durante processos inflamatórios (TATSUZAWA et al, 1999). Outros processos capazes de gerar oxigênio singlete são a peroxidação lipídica e transições redox de quinonas, ou ainda a partir da dismutação do superóxido em meio aquoso (KHAN, 1981, MONTHILAL et al, 2004.…”

Section: Formação Eros Em Sistemas Biológicosunclassified

Atividade do extrato de frutos de Pterodon emarginatus contra o estresse oxidativo e nitrosativo induzido por exercicio agudo em ratos

Paula¹,

Martins²

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Aos meus pais, Victor e Adélia, que sempre se dedicaram à minha formação pessoal e profissional, o meu profundo reconhecimento e eterna gratidão. Ao meu esposo, Alexandre pelo incentivo, compreensão, companheirismo e principalmente, por cuidar do nosso filho durante minha ausência. Ao meu filho Bruno, razão da minha luta e fonte inesgotável de alegria e luz em nossas vidas. v AGRADECIMENTOS -À Deus, pela sua presença maravilhosa em todos os momentos.-À Prof a Dra. Ione Salgado pela excelente orientação, pela dedicação e competência, sempre presentes. Obrigada pela disponibilidade e confiança no meu trabalho.-À Prof a Dra Cibele Marli Cação Paiva Gouvêa pela valiosa co-orientação, tanto na condução dos experimentos, como também, junto à versão escrita desta tese. Obrigada por acreditar na realização deste trabalho.-À estudante de iniciação científica, Patrícia Pereira Alfredo, pela dedicada contribuição junto aos experimentos, pela disponibilidade e pela amizade. Obrigada pelo compartilhamento de momentos sérios e também de descontração durante a realização deste trabalho, a qualquer hora do dia ou da noite -À Escola de Farmácia e Odontologia de Alfenas/Centro Universitário Federal (EFOA/Ceufe), pela oportunidade de afastamento para a realização deste trabalho e pelo empenho para conseguir a bolsa PICDT.-À Coordenação de aperfeiçoamento de pessoal de nível superior (Capes) pela concessão da bolsa.-Ao Prof. Dr. José Carlos Tavares Carvalho, que gentilmente forneceu o extrato hexânico bruto de frutos de Pterodon emarginatus.-À Prof a Dra. Maria Júlia.Alves Manso (Instituto de Química/USP) que gentilmente forneceu o material para a realização das análises de Western blotting.-A todos os profissionais dos laboratórios da EFOA/Ceufe, onde os experimentos foram realizados, que gentilmente disponibilizaram o uso de equipamentos essenciais à realização deste trabalho.-À todos os colegas do Laboratório de Bioquímica de Plantas, pela calorosa acolhida, e pela amizade que tornaram mais agradável minha estadia em Campinas. vi -À Profa. Dra. Elzira Elisabeth Saviani pelo suporte técnico durante a realização dos experimentos e também pela disponibilidade e ajuda com todo o cotidiano do laboratório.-Aos colegas e professores do Departamento de Análises Clínicas e Toxicológicas da EFOA/Ceufe pela colaboração.-À funcionária Eliane Batista Rocha, pela dedicada contribuição, seja no preparo dos materiais usados nos experimentos ou no cuidado com os animais.-Às secretárias do Instituto de Biologia/UNICAMP, Andréa e Marina, e à funcionária da pródiretoria de pesquisa da EFOA/Ceufe, Marylucia Prado dos Reis Soares pela constante atenção, disponibilidade e ajuda nos processos burocráticos.-Aos amigos Stella Maris, Maria Rita e Selmo, pela harmoniosa convivência e incentivo ao longo de todos estes anos em que trabalhamos juntos.

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Photosensitisation with naphthoquinones and binaphthoquinones: EPR spin trapping and optical studies-formation of semiquinone radical and reactive oxygen species on photoillumination

Cited by 10 publications

References 24 publications

Antifungal Metabolites from the Roots of Diospyros virginiana by Overpressure Layer Chromatography

Antifungal Metabolites from the Roots of Diospyros virginiana by Overpressure Layer Chromatography

An ultrasensitive and highly selective determination method for quinones by high-performance liquid chromatography with photochemically initiated luminol chemiluminescence

Atividade do extrato de frutos de Pterodon emarginatus contra o estresse oxidativo e nitrosativo induzido por exercicio agudo em ratos

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