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Photophysics and photochemistry of aflatoxins B1 and B2

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Abstract

Aflatoxins are mycotoxins produced by fungi of the genus Aspergillus, which is widely spread in the tropics and subtropics. To date, aflatoxin phototoxicity has been recognized, but the mechanism responsible for this phototoxicity has not been fully characterized. In the present paper, nanosecond laser flash photolysis studies allowed us to elucidate the photochemical processes undergone by two mycotoxins, namely aflatoxin B1 and B2, upon UV irradiation. In brief, photolysis (308 nm) of the aflatoxins leads to intersystem crossing, giving rise to their triplet excited state. The triplet state can readily be quenched by indole and hydroquinone, and also by molecular oxygen yielding singlet oxygen (singlet oxygen quantum yields of 0.51 and 0.59 were found for aflatoxin B1 and B2, respectively). In addition, our data indicate the ability of the two aflatoxins to photoionize upon 248 nm excitation. The photoionization quantum yield for aflatoxin B1 and B2 have been estimated to be 0.11 and 0.29, respectively.

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Notes and references

  1. M. A. Klich and J. I. J. I. Pitt, Differentiation of Aspergillus flavus from Aspergillus parasiticus and other closely related species, Trans. Br. Mycol. Soc., 1988, 91, 99.

    Article  Google Scholar 

  2. J. W. Dorner, Simultaneous quantitation of Aspergillus flavus, A. parasiticus and aflatoxin in peanuts, J. Assoc. Off. Anal. Chem., 2002, 85, 911.

    CAS  Google Scholar 

  3. J. Leitao, G. de Saint Blanquat, J. R. Bailly and C. Paillas, Quanti-tation of aflatoxins from various strains of Aspergillus in foodstuffs, J. Chromatogr., A, 1988, 435, 229.

    Article  CAS  Google Scholar 

  4. P. M. Scott, Mycotoxins: review, J. Assoc. Off. Anal. Chem., 1987, 70, 276.

    Google Scholar 

  5. A. Yiannikouris and J. P. Jouany, Mycotoxins in feeds and their fate in animals: a review, Anim. Res., 2002, 51, 81.

    Article  CAS  Google Scholar 

  6. M. E. Alpert, M. S. R. Hutt, G. N. Wogan and C. S. Davidson, Association between aflatoxin content of food and hepatoma frequency in Uganda, Cancer, 1971, 28, 253.

    Article  CAS  PubMed  Google Scholar 

  7. J. A. DiPaolo, J. Elis and H. Erwin, Teratogenic Response by Hamsters, Rats and Mice to Aflatoxin B1, Nature, 1967, 215, 638.

    Article  CAS  PubMed  Google Scholar 

  8. H. S. Hussein and J. M. Brasel, Toxicity, metabolism, and impact of mycotoxins on humans and animals, Toxicology, 2001, 167, 101.

    Article  CAS  PubMed  Google Scholar 

  9. M. Peraica, B. Radić, A. Lucić and M. Pavlović, Toxic effects of mycotoxins in humans, Bull. World Health Organ., 1999, 77, 754.

    CAS  PubMed  PubMed Central  Google Scholar 

  10. International Agency for Research on Cancer, Aflatoxins, IARC Monogr. Eval. Carcinog. Risks Hum., 1993, 56, 245.

    Google Scholar 

  11. C. N. Ou and P.-S. Song, Photobinding of 8-methoxypsoralen to transfer RNA and 5-fluorouracil-enriched transfer RNA, Biochemistry, 1978, 17, 1054.

    Article  CAS  PubMed  Google Scholar 

  12. G. Rodighiero and F. Dall’Acqua, Biochemical and medical aspects of psoralens, Photochem. Photobiol., 1976, 24, 647.

    Article  CAS  PubMed  Google Scholar 

  13. P.-S. Song and K. J. Tapley, Photochemistry and photobiology of psoralens, Photochem. Photobiol., 1979, 29, 1177.

    Article  CAS  PubMed  Google Scholar 

  14. J.-C. Shieh and P.-S. Song, Photochemically induced binding of Aflatoxins to DNA and its effects on template activity, Cancer Res., 1980, 40, 689.

    CAS  PubMed  Google Scholar 

  15. D. H. Swenson, J. Lin, E. C. Miller and J. A. Miller, Aflatoxin B1-2,3-oxide as a probable intermediate in the covalent binding of aflatoxins B1 and B2 to rat liver DNA and ribosomal RNA in vivo, Cancer Res., 1977, 37, 172.

    CAS  PubMed  Google Scholar 

  16. D. H. Swenson, E. C. Miller and J. A. Miller, Aflatoxin B1-2,3-oxide: evidence for its formation in rat liver in vivo and by human liver microsomes in vitro, Biochem. Biophys. Res. Commun., 1974, 60, 1036.

    Article  CAS  PubMed  Google Scholar 

  17. D. H. Swenson, J. A. Miller and E. C. Miller, 2,3-Dihydro-2,3-dihydroxy-aflatoxin B1: an acid hydrolysis product of an RNA-aflatoxin B1 adduct formed by hamster and rat liver microsomes in vitro, Biochem. Biophys. Res. Commun., 1973, 53, 1260.

    Article  CAS  PubMed  Google Scholar 

  18. W. R. Jones, D. S. Johnston and M. P. Stone, Site-specific synthesis of aflatoxin B1 adducts within an oligodeoxyribonucleotide containing the human p53 codon 249 sequence, Chem. Res. Toxicol., 1999, 12, 707.

    Article  CAS  PubMed  Google Scholar 

  19. R. G. Croy, J. M. Essigmann, V. N. Reinhold and G. N. Wogan, Identification of the principal aflatoxin B1-DNA adduct formed in vivo in rat liver, Proc. Natl. Acad. Sci. U. S. A., 1978, 75, 1745.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  20. J. M. Essigmann, R. G. Croy, A. M. Nadzan, W. F. Busby, V. N. Reinhold, G. Buchi and G. N. Wogan, Structural identification of the major DNA adduct formed by aflatoxin B1 in vitro, Proc. Natl. Acad. Sci. U. S. A., 1977, 74, 1870.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. J. Lin, J. A. Miller and E. C. Miller, 2,3-Dihydro-2-(guan-7-yl)-3-hydroxy-aflatoxin B1, a major acid hydrolysis product of aflatoxin B1-DNA or -ribosomal RNA adducts formed in hepatic microsome-mediated reactions and in rat liver in vivo, Cancer Res., 1977, 37, 4430.

    CAS  PubMed  Google Scholar 

  22. R. G. Croy and G. N. Wogan, Temporal patterns of covalent DNA adducts in rat liver after single and multiple doses of aflatoxin B1, Cancer Res., 1981, 41, 197.

    CAS  PubMed  Google Scholar 

  23. J.-S. Wang and J. D. Groopman, DNA damage by mycotoxins, Mutat. Res., Fundam. Mol. Mech. Mutagen., 1999, 424, 167.

    Article  CAS  Google Scholar 

  24. J. J. Wong and D. P. H. Hsieh, Mutagenicity of aflatoxins related to their metabolism and carcinogenic potential, Proc. Natl. Acad. Sci. U. S. A., 1976, 73, 2241.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  25. H. M. Shen, C. N. Ong and C. Y. Shi, Involvement of reactive oxygen species in aflatoxin B1-induced cell injury in cultured rat hepatocytes, Toxicology, 1995, 99, 115.

    Article  CAS  PubMed  Google Scholar 

  26. R. C. Guedes and L. A. Eriksson, Theoretical characterization of aflatoxins and their phototoxic reactions, Chem. Phys. Lett., 2006, 422, 328.

    Article  CAS  Google Scholar 

  27. B. Heyne, D. Brault, M.-P. Fontaine-Aupart, S. Kohnen, F. Tfibel, A. Mouithys-Mickalad, G. Deby-Dupont, P. Hans and M. Hoebeke, Reactivity towards singlet oxygen of propofol inside liposomes and neuronal cells, Biochim. Biophys. Acta, Gen. Subj., 2005, 1724, 100.

    Article  CAS  Google Scholar 

  28. J. C. Scaiano, Solvent effects in the photochemistry of xanthone, J. Am. Chem. Soc., 1980, 102, 7747.

    Article  CAS  Google Scholar 

  29. J. C. Scaiano, M. Tanner and D. Weir, Exploratory Study of the Intermolecular Reactivity of Excited Diphenylmethyl Radicals, J. Am. Chem. Soc., 1985, 107, 4396.

    Article  CAS  Google Scholar 

  30. O. Stern and M. Volmer, Über die Abklingzeit der Fluoreszenz, Physik. Z., 1919, 20, 183.

    CAS  Google Scholar 

  31. L. Chen, O. Rinco, J. Popov, N. Vuong and L. J. Johnston, Psoralen and Coumarin Photochemistry in HSA Complexes and DMPC Vesicles, Photochem. Photobiol., 2006, 82, 31.

    Article  CAS  PubMed  Google Scholar 

  32. I. Carmichael, W. P. Helman and G. L. Hug, Extinction Coefficients of Triplet-Triplet Absorption Spectra of Organic Molecules in Condensed Phases: A Least-Squares Analysis, J. Phys. Chem. Ref. Data, 1987, 16, 239.

    Article  CAS  Google Scholar 

  33. E. M. Fielden and E. J. Hart, Primary radical yields in pulse-irradiated alkaline aqueous solution, Radiat. Res., 1967, 32, 564.

    Article  CAS  PubMed  Google Scholar 

  34. F. Wilkinson, D. J. McGarvey and A. F. Olea, Excited Triplet State Interactions with Molecular Oxygen: Influence of Charge Transfer on the Bimolecular Quenching Rate Constants and the Yields of Singlet Oxygen (O21Dg) for Substituted Naphthalenes in Various Solvents, J. Phys. Chem., 1994, 98, 3762.

    Article  CAS  Google Scholar 

  35. G. R. Buettner and L. W. Oberley, Considerations in the spin trapping of superoxide and hydroxyl radical in aqueous systems, Biochem. Biophys. Res. Commun., 1978, 83, 69.

    Article  CAS  PubMed  Google Scholar 

  36. B. Heyne, V. Maureland J. C. Scaiano, Mechanism of action of sensors for reactive oxygen species based on fluorescein-phenol coupling: the case of 2-[6-(4’-hydroxy)phenoxy-3H-xanthen-3-on-9-yl]benzoic acid, Org. Biomol. Chem., 2006, 4, 802.

    Article  CAS  PubMed  Google Scholar 

  37. H. W. Dirr, Solvent effects on the spectroscopic properties of aflatoxin B1, Int. J. Biochem., 1987, 19, 1137.

    Article  CAS  PubMed  Google Scholar 

  38. J. Jaimez, C. A. Fente, B. I. Vazquez, C. M. Franco, A. Cepeda, G. Mahuzier and P. Prognon, Application of the assay of aflatoxins by liquid chromatography with fluorescence detection in food analysis, J. Chromatogr., A, 2000, 882, 1.

    Article  CAS  Google Scholar 

  39. M. Aghamohammadi and N. Alizadeh, Fluorescence enhancement of the aflatoxin B1 by forming inclusion complexes with some cyclodex-trins and molecular modeling study, J. Lumin., 2007, 127, 575.

    Article  CAS  Google Scholar 

  40. R. Bensasson, E. J. Land and B. Mavdinas, Triplet-states of Carotenoids from photosynthetic bacteria studied by nanosecond ultraviolet and electron pulse irradiation, Photochem. Photobiol, 1976, 23, 189.

    Article  CAS  PubMed  Google Scholar 

  41. C. V. Kumar, S. Chattopadhay and P. K. Das, Triplet excitation transfer to carotenoids from biradical intermediates in Norrish type-II pho-toreactions of ortho-alkyl-substituted aromatic carbonyl compounds, J. Am. Chem. Soc., 1983, 105, 5143.

    Article  CAS  Google Scholar 

  42. J. C. Scaiano and M. V. Encinas, Reaction of benzophenone triplets with allylic hydrogen -a laser flash photolysis study, J. Am. Chem. Soc, 1981, 103, 6393.

    Article  Google Scholar 

  43. S. V. Jovanovic, D. G. Morris, C. N. Pliva and J. C. Scaiano, Laser flash photolysis of dinaphthylketones, J. Photochem. Photobiol, A, 1997, 107, 153.

    Article  CAS  Google Scholar 

  44. K. M. Bansal and R. W. Fessenden, Pulse Radiolysis Studies of the Oxidation of Phenols by ·SO4− and Br2− in Aqueous Solutions, Radiat. Res., 1976, 67, 1.

    Article  CAS  PubMed  Google Scholar 

  45. R. H. Schuler, P. Neta, H. Zemel and R. W. Fessenden, Conversion of hydroxyphenyl to phenoxyl radicals-radiolytic study of reduction of bromophenols in aqueous solution, J. Am. Chem. Soc, 1976, 98, 3825.

    Article  CAS  Google Scholar 

  46. S. V. Jovanovic and S. Steenken, Substituent effects on the spectral, acid-base, and redox properties of indolyl radicals: a pulse radiolysis study, J. Phys. Chem., 1992, 96, 6674.

    Article  CAS  Google Scholar 

  47. J. Perez-Prieto, F. Bosca, R. E. Galian, A. Lahoz, L. R. Domingo and M. A. Miranda, Photoreaction between 2-benzoylthiophene and phenol or indole, J. Org. Chem., 2003, 68, 5104.

    Article  CAS  PubMed  Google Scholar 

  48. L. Biczok, T. Berces and H. Linschitz, Quenching processes in hydrogen-bonded pairs: interactions of excited fluorenone with alcohols and phenols, J. Am. Chem. Soc, 1997, 119, 11071.

    Article  CAS  Google Scholar 

  49. W. J. Leigh, E. C. Lathioor and M. J. St Pierre, Photoinduced hydrogen abstraction from phenols by aromatic ketones A new mechanism for hydrogen abstraction by carbonyl n,π* and p,p* triplets, J. Am. Chem. Soc, 1996, 118, 12339.

    Article  CAS  Google Scholar 

  50. M. A. Miranda, A. Lahoz, R. Matínez-Manez, F. Bosca, J. V. Castell and J. Perez-Prieto, Enantioselective discrimination in the intramolecular quenching of an excited aromatic ketone by a ground state phenol, J. Am. Chem. Soc, 1999, 121, 11569.

    Article  CAS  Google Scholar 

  51. N. C. de Lucas, R. J. Correa, A. C C. Albuquerque, C. L. Firme, S. J. Garden, A. R. Bertoti and J. C. Netto-Ferreira, Laser flash photolysis of 1,2-diketopyracene and a theoretical study of the phenolic hydrogen abstraction by the triplet state of cyclic α-diketones, J. Phys. Chem. A, 2007, 111, 1117.

    Article  PubMed  CAS  Google Scholar 

  52. J. C. Netto-Ferreira, B. Bernardes, A. B. B. Ferreira and M. A. Miranda, Laser flash photolysis study of the triplet reactivity of β-lapachones, Photochem. Photobiol. Sci., 2008, 7, 467.

    Article  CAS  PubMed  Google Scholar 

  53. J. C. Netto-Ferreira, V. Lhiaubet-Vallet, B. Bernardes, A. B. B. Ferreira and M. A. Miranda, Characterization, reactivity and photosensitizing properties of the triplet excited state of α-lapachone, Phys. Chem. Chem. Phys., 2008, 10, 6645.

    Article  CAS  PubMed  Google Scholar 

  54. J. C. Netto-Ferreira, V. Lhiaubet-Vallet, B. Bernardes, A. B. B. Ferreira and M. A. Miranda, Photosensitizing Properties of Triplet β-Lapachones in Acetonitrile Solution, Photochem. Photobiol., 2009, 85, 153.

    Article  CAS  PubMed  Google Scholar 

  55. N. C. de Lucas, M. M. Elias, C. L. Firme, R. J. Correa, S. J. Garden, J. C. Netto-Ferreira and D. E. Nicodem, A combined laser flash photolysis, density functional theory and atoms in molecules study of the photochemical hydrogen abstraction by pyrene-4,5-dione, J. Photochem. Photobiol., A, 2009, 201, 1.

    Article  CAS  Google Scholar 

  56. T. Chen, M. S. Platz, M. Robert, J.-M. Saveant, A. Marcinek, J. Rogowski, J. Gebicki, Z. Zhu and T. Bally, Electron transfer chemistry of psoralens and coumarins derivatives by means of pulse radiolytic and electrochemical experiments, J. Phys. Chem. A, 1997, 101, 2124.

    Article  CAS  Google Scholar 

  57. S. Rai, C. Kasturi, J. Grayzar, M. S. Platz, R. P. Goodrich, N. R. Yerram, V. Wong and B. H. Tay-Goodrich, Dramatic improvements in viral inactivation with brominated psoralens, naphthalenes and anthracenes, Photochem. Photobiol., 1993, 58, 59.

    Article  CAS  PubMed  Google Scholar 

  58. Z. Shaquiri, E. Keskinova, A. Spassky and D. Angelov, A Picosecond Flash-Photolysis Study of the Biphotonic Ionization of Psoralen Derivatives and Ethidium Bromide, Photochem. Photobiol., 1997, 65, 517.

    Article  Google Scholar 

  59. R. W. Sloper, T. G. Truscott and E. J. Land, The triplet state of 8-methoxypsoralen, Photochem. Photobiol., 1979, 29, 1025.

    Article  CAS  Google Scholar 

  60. H. K. Kang, E. J. Shin and S. C. Shim, Comparison of Photophysical and Photochemical Properties of Khellin and 8-methoxypsoralen, Bull. Korean Chem. Soc., 1991, 12, 554.

    CAS  Google Scholar 

  61. M. M. Collet, M. Hoebeke, J. Piette, A. Jakobs, L. Lindqvist and A. Van de Vorst, Photosensitized generation of hydroxyl radical by eight new sulfur and selenium analogs of psoralen, J. Photochem. Photobiol., B, 1996, 35, 221.

    Article  CAS  Google Scholar 

  62. R. V. Bensasson, O. Chalvet, E. J. Land and J. C. Ronfard-Haret, Triplet, radical anion and radical cation spectra of furocoumarins, Photochem. Photobiol., 1984, 39, 287.

    Article  CAS  PubMed  Google Scholar 

  63. P. D. Wood and L. J. Johnston, Generation and Characterization of Psoralen Radical Cations, Photochem. Photobiol., 1997, 66, 642.

    Article  CAS  Google Scholar 

  64. P. D. Wood and L. J. Johnston, Electron-Transfer Reactions in Micelles: Dynamics of Psoralen and Coumarin Radical Cations, J. Phys. Chem., 1998, 102, 5585.

    Article  CAS  Google Scholar 

  65. P. D. Wood, A. Mnyusiwalla, L. Chen and L. J. Johnston, Reactions of Psoralen Radical Cations with Biological Substrates, Photochem. Photobiol., 2000, 72, 155.

    Article  CAS  PubMed  Google Scholar 

  66. J. Kagan, X. Chen, T. P. Wang and P. Forlot, Psoralens cleave pBR322 DNA under ultraviolet radiation, Photochem. Photobiol., 1992, 56, 185.

    Article  CAS  PubMed  Google Scholar 

  67. L. Chen, P. D. Wood, A. Mnyusiwalla, J. Marlinga and L. J. Johnston, Electron Transfer Reactions in Micelles: Dynamics of Psoralen and Coumarin Radical Cations, J. Phys. Chem. B, 2001, 105, 10927.

    Article  CAS  Google Scholar 

  68. F. Wilkinson, W. P. Helman and A. B. Ross, Rate Constants for the Decay and Reactions of the Lowest Electronically Excited Singlet-State of Molecular Oxygen in Solution, J. Phys. Chem. Ref. Data, 1995, 24, 663.

    Article  CAS  Google Scholar 

  69. A. P. Darmanyan and C. S. Foote, Solvent Effects on Singlet Oxygen Yield from n,π* and p,p* Triplet Carbonyl Compounds, J. Phys. Chem., 1993, 97, 5032.

    Article  CAS  Google Scholar 

  70. R. W. Redmond and S. E. Braslavsky, Time-resolved thermal lensing and phosphorescence studies on photosensitized singlet molecular oxygen formation-Influence of the electronic configuration of the sensitizer on sensitization efficiency, Chem. Phys. Lett., 1988, 148, 523.

    Article  CAS  Google Scholar 

  71. R. Schmidt, C. Tanielian, R. Dunsbach and C. Wolff, Phenalenone, a universal reference compound for the determination of quantum yields of singlet oxygen O21Dg) sensitization, J. Photochem. Photobiol., A, 1994, 79, 11.

    Article  CAS  Google Scholar 

  72. E. Oliveros, P. Suardi-Murasecco, T. Aminian-Saghafi, A. M. Braun and H.-J. Hansen, 1H-Phenalen-1-one. Photophysical properties and singlet oxygen production, Helv. Chim. Acta, 1991, 74, 79.

    Article  CAS  Google Scholar 

  73. W. M. Nau and J. C. Scaiano, Oxygen quenching of excited aliphatic ketones and diketones, J. Phys. Chem., 1996, 100, 11360.

    Article  CAS  Google Scholar 

  74. A. E. Hora Machado, J. A. Miranda, A. M. F. Oliveira-Campos, D. Severino and D. E. Nicodem, Photophysical properties of two new psoralen analogs, J. Photochem. Photobiol., A, 2001, 146, 75.

    Article  Google Scholar 

  75. R. A. Towner, R. P. Mason and L. A. Reinke, Detection of alfatoxin-induced lipid free radicals in rat bile, Biochim. Biophys. Acta, Gen. Subj., 2002, 1573, 55.

    Article  CAS  Google Scholar 

  76. P. Bilski, K. Reszka, M. Bilska and C. F. Chignell, Oxidation of the Spin Trap 5,5-Dimethyl-1-pyrroline N-Oxide by Singlet Oxygen in Aqueous Solution, J. Am. Chem. Soc., 1996, 118, 1330.

    Article  CAS  Google Scholar 

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  1. Department of Chemistry and Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario, K1N 6N5, Canada

    J. C. Netto-Ferreira, B. Heyne & J. C. Scaiano

  2. Departamento de Química, Universidade Federal Rural do Rio de Janeiro, Antiga Rio-São Paulo km 47, Seropédica, 23851-970, Rio de Janeiro, Brazil

    J. C. Netto-Ferreira

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Note: Since aflatoxins are one of the most toxic known substances for both animals and humans some precautions must be taken when handling this type of chemical. All work must be performed in a fume hood. After use, all labware must be left in a sodium hypochlorite (technical grade, 12% w/w solution) for at least 5 min, then submerged in a dishwashing solution and thoroughly washed with clean water. For disposable materials such as glassware, lab coat and gloves, they must be soaked inside a tightly closed container properly labeled and containing a bleach solution (same concentration as before), which must be discarded only by qualified experienced professionals.

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Netto-Ferreira, J.C., Heyne, B. & Scaiano, J.C. Photophysics and photochemistry of aflatoxins B1 and B2. Photochem Photobiol Sci 10, 1701–1708 (2011). https://doi.org/10.1039/c1pp05103b

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