Applied Microbiology and Biotechnology

, Volume 78, Issue 2, pp 343–349 | Cite as

Aspergillus niger metabolism of citrus furanocoumarin inhibitors of human cytochrome P450 3A4

  • Kyung MyungEmail author
  • John A. Manthey
  • Jan A. Narciso
Applied Microbial and Cell Physiology


Fungi metabolize polycyclic aromatic hydrocarbons by a number of detoxification processes, including the formation of sulfated and glycosidated conjugates. A class of aromatic compounds in grapefruit is the furanocoumarins (FCs), and their metabolism in humans is centrally involved in the “grapefruit/drug interactions.” Thus far, the metabolism by fungi of the major FCs in grapefruit, including 6′, 7′-epoxybergamottin (EB), 6′, 7′-dihydroxybergamottin (DHB), and bergamottin (BM), has received little attention. In this study, Aspergillus niger was observed to convert EB into DHB and a novel water-soluble metabolite (WSM). Bergaptol (BT) and BM were also metabolized by A. niger to the WSM, which was identified as BT-5-sulfate using mass spectrometry, UV spectroscopy, chemical hydrolysis, and 1H and 13C nuclear magnetic resonance spectroscopy. Similarly, the fungus had a capability of metabolizing xanthotoxol (XT), a structural isomer of BT, to a sulfated analog of BT-5-sulfate, presumably XT-8-sulfate. A possible enzyme-catalyzed pathway for the grapefruit FC metabolism involving the cleavage of the geranyl group and the addition of a sulfate group is proposed.


Aspergillus niger Furanocoumarins 6′, 7′-Epoxybergamottin 6′, 7′-Dihydroxybergamottin Bergamottin Bergaptol Xanthotoxol Bergaptol-5-sulfate Xanthotoxol-8-sulfate 



We thank Ms. Veronica Cook and Mr. Christopher Ference for their technical assistance. We also thank Spectral Data Service (Champaign, IL) for NMR analysis. Mention of a trademark or proprietary product is for identification only and does not imply a guarantee or warranty of the product by the US Department of Agriculture.


  1. Afek U, Orenstein J, Carmeli S, Rodov V, Joseph MB (1999) Umbelliferone, a phytoalexin associated with resistance of immature Marsh grapefruit to Penicillium digitatum. Phytochemistry 50:1129–1132CrossRefGoogle Scholar
  2. Barron D, Varin L, Ibrahim RK, Harborne JB, Williams CA (1988) Sulphated flavonoids—an update. Phytochemistry 27:2375–2395CrossRefGoogle Scholar
  3. Coughtrie MW (2002) Sulfation through the looking glass-recent advances in sulfotransferase research for the curious. Pharmacogenomics J 2:297–308CrossRefGoogle Scholar
  4. Farooq A, Tahara S (1999) Fungal metabolism of flavonoids and related phytoalexins. Curr Top Phytochem 2:1–33Google Scholar
  5. Fisher JF, Nordby HE (1965) Isolation and spectral characterization of coumarins in Florida grapefruit peel oil. J Food Sci 30:869–873CrossRefGoogle Scholar
  6. Girennavar B, Jayaprakasha GK, Jadegoud J, Nagana Gowda GA, Patil BS (2007) Radical scavenging and cytochrome P450 3A4 inhibitory activity of bergaptol and geranylcoumarin from grapefruit. Bioorg Med Chem 15:3684–3691CrossRefGoogle Scholar
  7. Golbeck JH, Albaugh SA, Radmer R (1983) Metabolism of biphenyl by Aspergillus toxicarius: induction of hydroxylating activity and accumulation of water-soluble conjugates. J Bacteriol 156:49–57CrossRefGoogle Scholar
  8. Guo L-Q, Fukuda K, Ohta T, Yamazoe Y (2000) Role of furanocoumarin derivatives on grapefruit juice-mediated inhibition of human CYP3A activity. Drug Metab Dispos 28:766–771PubMedGoogle Scholar
  9. Kotik M, Kyslík P (2006) Purification and characterisation of a novel enantioselective epoxide hydrolase from Aspergillus niger M200. Biochim Biophys Acta 1760:245–252CrossRefGoogle Scholar
  10. Manthey JA, Buslig BA (2005) Distribution of furanocoumarins in grapefruit juice fractions. J Agric Food Chem 53:5158–5163CrossRefGoogle Scholar
  11. Manthey JA, Myung K, Merten-Talcott S, Derendorf H, Butterweck V, Widmer WW (2006) The isolation of minor-occurring furanocoumarins in grapefruit and analysis of their inhibition of CYP3A4 and P-glycoprotein transport of talinolol from Caco-2 cells. Proc Fla State Hort Soc 119:361–366Google Scholar
  12. Morisseau C, Archelas A, Guitton C, Faucher D, Furstoss R, Baratti JC (1999) Purification and characterization of a highly enantioselective epoxide hydrolase from Aspergillus niger. Eur J Biochem 263:386–395CrossRefGoogle Scholar
  13. Murray RDH, Mendés J, Brown SA (1982) The natural coumarins: occurrence, chemistry, and biochemistry. Wiley, New YorkGoogle Scholar
  14. Myung K, Hamilton-Kemp TR, Archbold DD (2007) Interaction with and effects on the profile of proteins of Botrytis cinerea by C6 aldehydes. J Agric Food Chem 55:2182–2188CrossRefGoogle Scholar
  15. Myung K, Mathey JA, Narciso JA (2008) Binding of furanocoumarins in grapefruit juice to Aspergillus niger hyphae. (in press) DOI CrossRefGoogle Scholar
  16. Oliva A, Meepagala K, Wedge DE, Harries D, Hale AL, Aliotta G, Duke SO (2003) Natural fungicides from Ruta graveolens L. leaves, including a new quinolone alkaloid. J Agric Food Chem 51:890–896CrossRefGoogle Scholar
  17. Papagianni M (2004) Fungal morphology and metabolite production in submerged mycelial processes. Biotechnol Adv 22:189–259CrossRefGoogle Scholar
  18. Pothuluri JV, Sutherland JB, Freeman JP, Cerniglia CE (1998) Fungal biotransformation of 6-nitrochrysene. Appl Environ Microbiol 64:3106–3109CrossRefGoogle Scholar
  19. Santana L, Uriarte E, Roleira F, Milhazes N, Borges F (2004) Furocoumarins in medicinal chemistry. Synthesis, natural occurrence and biological activity. Curr Med Chem 11:3239–3261CrossRefGoogle Scholar
  20. Smit MS (2004) Fungal epoxide hydrolases: new landmarks in sequence-activity space. Trends Biotechnol 22:123–129CrossRefGoogle Scholar
  21. Spencer GF, Desjardins AE, Plattner RD (1990) 5-(2-carboxyethyl)-6-hydroxy-7-methoxybenzofuran, a fungal metabolite of xanthotoxin. Phytochemistry 29:2495–2497CrossRefGoogle Scholar
  22. Sun L, Huang HH, Liu L, Zhong DF (2004) Transformation of verapamil by Cunninghamella blakesleeana. Appl Environ Microbiol 70:2722–2727CrossRefGoogle Scholar
  23. Tassaneeyakul W, Guo L-Q, Fukuda K, Ohta T, Yamazoe Y (2000) Inhibition selectivity of grapefruit juice components on human cytochromes P450. Arch Biochem Biophys 15:356–363CrossRefGoogle Scholar
  24. Tatum JH, Berry RE (1979) Coumarins and psoralens in grapefruit peel oil. Phytochemistry 18:500–502CrossRefGoogle Scholar
  25. Teng WY, Huang YL, Huang RL, Chung RS, Chen CC (2004) Biotransformation of imperatorin by Aspergillus flavus. J Nat Prod 67:1014–1017CrossRefGoogle Scholar
  26. Weimin L, Schuler MA, Berenbaum MR (2003) Diversification of furanocoumarin-metabolizing cytochrome P450 monooxygenases in two papilionids: specificity and substrate encounter rate. Proc Natl Acad Sci USA 100:14593–14598CrossRefGoogle Scholar
  27. Widmer WW, Haun C (2005) Variation in furanocoumarin content and new furanocoumarin dimers in commercial grapefruit (Citrus paradisi Macf.) juices. J Food Sci 70:C307–C312CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Kyung Myung
    • 1
    Email author
  • John A. Manthey
    • 1
  • Jan A. Narciso
    • 1
  1. 1.Citrus and Subtropical Products Laboratory, Agricultural Research ServiceUS Department of AgricultureWinter HavenUSA

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