Skip to main content

Cyanide in Foods

Biology of Cyanogenic Glucosides and Related Nutritional Problems

  • Chapter
Book cover Phytochemicals in Human Health Protection, Nutrition, and Plant Defense

Part of the book series: Recent Advances in Phytochemistry ((RAPT,volume 33))

Abstract

Plants that are able to liberate significant amounts of HCN are referred to as cyanogenic. The main source of the cyanide is the so-called cyanogenic glucosides. These compounds consist of α-hydroxynitriles, also called cyanohydrins, which are stabilized by a sugar. Nearly 3,000 plant species have been reported to be cyanogenic.1,2 The HCN liberated from cyanogenic plants is thought to be an important ecological factor, e.g. in plant defence against herbivores, and must be clearly distinguished from low levels of HCN production during ethylene biosynthesis in intact plants.3 The amounts of HCN produced during ethylene synthesis are several magnitudes lower than those concentrations resulting from cyanogenesis due to tissue disruption.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 169.00
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 219.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info
Hardcover Book
USD 219.99
Price excludes VAT (USA)
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. SEIGLER, D.S. 1991. Cyanide and cyanogenic glycosides, pp. 35–77 in Herbivores: Their Interaction with Secondary Plant Metabolites, Volume I: The Chemical Participants (G.A. Rosenthal and M.R. Berenbaum, eds.), Academic Press, San Diego.

    Google Scholar 

  2. MØLLER, B.L., SEIGLER, D.S. 1998. Biosynthesis of cyanogenic glucosides, cyanolipids and related compounds, pp. 563–609 in Plant Amino Acids: Biochemistry and Biotechnology (B.K. Singh, ed.), Dekker Press, New York.

    Google Scholar 

  3. JOHN, P. 1997. Ethylene biosynthesis: The role of 1-aminocyclopropane-1-carboxylate (ACC) oxidase, and its possible evolutionary origin. Physiol. Plantarum 100(3): 583–592.

    Article  CAS  Google Scholar 

  4. SELMAR, D. 1999. Cyanogenic glycosides, glucosinolates and non-protein amino acids. in Annual Plant Reviews Volume 2: The Role of Secondary Metabolites and Their Utilization in Biotechnology (M. Wink, ed.), in press, Sheffield Academic Press.

    Google Scholar 

  5. POULTON, J.E. 1990. Cyanogenesis in plants. Plant Physiol. 94: 401–405.

    Article  PubMed  CAS  Google Scholar 

  6. NAHRSTEDT, A. 1992. The biology of the cyanogenic glycosides: New developments, pp. 249–269 in Annual Proceedings of the Phytochemical Society of Europe 29: Nitrogen Metabolism in Plants (K. Mengel and D.J. Pilbeam, eds.), Oxford University Press, Oxford.

    Google Scholar 

  7. NAHRSTEDT, A. 1987. Recent developments in chemistry, distribution and biology of the cyanogenic glycosides, pp. 213–234 in Annual Procedings of the Phytochemical Society of Europe 24: Biologically Active Natural Products (K. Hostettmann, P.J. Lea, eds.), Oxford University Press, Oxford.

    Google Scholar 

  8. HEGNAUER, R. 1986. Chemotaxonomie der Pflanzen Vol. VII, Birkhäuser Verlag, Basel-Stuttgart.

    Google Scholar 

  9. BRINKER, A.M., SEIGLER, D.S. 1992. Determination of cyanide and cyanogenic glycosides, pp. 359–381 in Modern Methods of Plant Analysis. New Series, Volume 13: Plant Toxin Analysis (H.F. Linskens and J.E Jackson, eds.), Springer, Berlin.

    Google Scholar 

  10. NAHRSTEDT, A. 1985. Cyanogenic compounds as protecting agents for organisms. Plant Syst. Evol. 105: 35–47.

    Article  Google Scholar 

  11. KAKES, P. 1990. Properties and function of the cyanogenic system in higher plants. Euphytica 48: 25–43.

    CAS  Google Scholar 

  12. HALKIER, B.A., SCHELLER, H.V., MØLLER, B.L. 1988. Cyanogenic glucosides: The biosynthetic pathway and the enzyme system involved, pp. 49–61 in Cyanide Compounds in Biology (D. Everett, S. Harnett, eds.), Wiley & Sons, Chichester, UK.

    Google Scholar 

  13. CONN, E.E. 1988. Biosynthetic relationship among cyanogenic glycosides, glucosinolates, and nitro compounds, pp. 143–154 in Biologically Active Natural Products: Potential Use in Agriculture (G. Cutler, ed.), American Chemical Society, Washington, DC.

    Chapter  Google Scholar 

  14. NAHRSTEDT, A. 1993. Cyanogenesis is foodplants. pp. 107–129 in Annual Proceedings of the Phytochemical Society of Europe: Phytochemistry and Agriculture (TA. van Beek, H. Breteler, eds.), Oxford University Press, Oxford.

    Google Scholar 

  15. POULTON, J.E. 1989. Toxic compounds in foodstuffs: Cyanogens, pp. 381–401 in Food Proteins. (J.E. Kinsella and W.G. Soucie, eds.), American Oil Chemists’ Society, Champaign, IL.

    Google Scholar 

  16. JONES, D.A. 1998. Why are so many food plants cyanogenic? Phytochemistry 47(2): 155–162.

    Article  PubMed  CAS  Google Scholar 

  17. SOLOMONSON, L.P. 1981. Cyanide as a metabolic inhibitor, pp. 11–28 in Cyanide in Biology (B. Vennesland, E.E. Conn, C.J. Knowles, J. Westley, F. Wissing, eds.), Academic Press, London.

    Google Scholar 

  18. MONTGOMERY, R.D. 1969. Cyanogens, in Toxic Constituents of Plant Foodstuffs (I.E. Liener, ed.), Academic Press, London.

    Google Scholar 

  19. SAUNDERS, J.A., CONN, E.E. 1977. Subcellular localization of the cyanogenic glucoside in Sorghum by autoradiography. Plant Physiol. 59: 647–652.

    Article  PubMed  CAS  Google Scholar 

  20. GRUHNERT, Ch., BIEHL, B., SELMAR, D. 1994. Compartmentation of cyanogenic glucosides and their degrading enzymes. Plant Physiol. 195: 36–42.

    CAS  Google Scholar 

  21. SWAIN, E., LI, C.P., POULTON, J.E. 1992. Tissue and subcellular localization of enzymes catabolizing (R)-amygdalin in mature Prunus serotina seeds. Plant Physiol. 100(1): 291–300.

    Article  PubMed  CAS  Google Scholar 

  22. SELMAR, D. 1993. Apoplastic occurrence of cyanogenic β-glucosidases and consequences for the metabolism of cyanogenic glucosides. pp. 191–204 in The Biochemistry and Molecular Biology of β-Glucosidases (A. Esens, ed.), American Chemical Society, Washington.

    Chapter  Google Scholar 

  23. POULTON, J.E. 1988. Localization and catabolism of cyanogenic glucosides. pp. 67–81 in Cyanide Compounds in Biology (D. Everett, S. Harnett, eds.), Wiley & Sons, Chichester.

    Google Scholar 

  24. HÖSEL, W., NAHRSTEDT, A. 1975. Spezifische Glucosidasen für das Cyanglucosid Triglochinin, Reinigung und Charakterisierung von β-Glucosidasen aus Alocasia macrorrhiza, Schott). Hoppe-Seyler’s Z. für Physiol. Chemie 356: 1265–1275.

    Article  Google Scholar 

  25. NAHRSTEDT, A., HÖSEL, W., WALTHER, A. 1979. Characterisation of cyanogenic glucosides and -glucosidases in Triglochin maritima seedlings. Phytochemistry 18: 1137–1141.

    Article  CAS  Google Scholar 

  26. HÖSEL, W., TOBLER, I., EKLUND, S.H., CONN, E.E. 1987. Characterization of β-glucosidases with high specificity for the cyanogenic glucoside dhurrin in Sorghum bicolor (L.) Moench seedlings. Arch. Biochem. Biophys. 252: 152–162.

    Article  PubMed  Google Scholar 

  27. KUROKI, G.W., POULTON, J.E. 1986. Comparison of kinetic and molecular properties of two forms of amygdalin hydrolase from black cherry (Prunus serotina Ehrh.) seeds. Arch. Biochem. Biophys. 247: 433–439.

    Article  PubMed  CAS  Google Scholar 

  28. FAN, T.W.M., CONN, E.E. 1985. Isolation and characterization of two β-glucosidases from flax seeds. Arch. Biochem. Biophys. 243: 361–373.

    Article  PubMed  CAS  Google Scholar 

  29. YEOH, H.-H. 1989. Kinetic properties of β-glucosidase from cassava. Phytochemistry 28: 721–724.

    Article  CAS  Google Scholar 

  30. SELMAR, D., LIEBEREI, R., BIEHL, B., VOIGT, J. 1987. Linamarase in Hevea—a nonspecific β-glycosidase. Plant Physiol. 83: 557–563.

    Article  PubMed  CAS  Google Scholar 

  31. KOCH, B.M., SIBBESEN, O., HALKIER, B.A., SVENDSEN, I., MØLLER, B.L. 1995. The primary sequence of cytochrome P450tyr, the multifunctional N-hydroxylase catalyzing the conversion of L-tyrosine to p-hydroxyphenylacetaldehyde oxime in the biosynthesis of the cyanogenic glucoside dhurrin in Sorghum bicolor (L.) Moench. Arch. Biochem. Biophys. 323(1): 177–186.

    Article  CAS  Google Scholar 

  32. SIBBESEN, O., KOCH, B., HALKIER, B.A., MØLLER, B.L. 1994. Isolation of the heme-thiolate enzyme cytochrome P-450-TYR, which catalyzes the committed step in the biosynthesis of the cyanogenic glucoside dhurrin in Sorghum bicolor (L.) Moench. Proc. Natl. Acad. Sci. USA 91(21): 9740–9744.

    Article  CAS  Google Scholar 

  33. SIBBESEN, O., KOCH, B., HALKIER, B.A., MØLLER, B.L. 1995. Cytochrome P-450-TYR is a multifunctional heme-thiolate enzyme catalyzing the conversion of L-tyrosine to p-hydroxy-phenylacetaldehyde oxime in the biosynthesis of the cyanogenic glucoside dhurrin in Sorghum bicolor (L.) Moench. J. Biol. Chem. 270(8): 3506–3511.

    CAS  Google Scholar 

  34. OLAFSDOTTIR, S., ANDERSEN, J.V., JAROSZEWSKI, J.W. 1989. Cyanohydrin glycosides of Passifloraceae. Phytochemistry 28(1): 127–132.

    Article  CAS  Google Scholar 

  35. VAN BEL, A.J.E. 1989. The challenge of symplastic phloem loading. Botanica Acta 102: 183–185.

    Google Scholar 

  36. KUROKI, G., LIZOTTE, P.A., POULTON, J.E. 1984. Catabolism of (R)-amygdalin and (R)-vicianin by partually purified β-glucosidases from Prunus serotina Ehrh. and Davallia trichomanoides. Zeit. Naturforsch. 39: 232–239.

    Google Scholar 

  37. BLUMENTHAL, G.S., HENDRICKSON, H.R., ABROL, YP, CONN, E.E. 1961. Cyanide metabolism in higher plants. J. Biol. Chem. 243: 5302–5307.

    Google Scholar 

  38. CASTRIC, P.A., FARNDEN, K.F., CONN, E.E. 1972. Cyanide metabolism in higher plants. 5: The formation of asparagine from β-cyanoalanine. Arch. Biochem. Biopys. 152: 62–69.

    Article  CAS  Google Scholar 

  39. WOODHEAD, S., BERNAYS, E. 1977. Changes in release rates of cyanide in relation to palatability of Sorghum to insects. Nature 279: 235–236.

    Article  Google Scholar 

  40. BERNAYS, E.A., CHAPMAN, R.F., LEATHER, E.M., MCCAFFERY, A.R., MODDER, W.W.D. 1977. The Relationship of Zonocerus variegatus with cassava. Bull. Ent. Res. 67: 391–404.

    Article  Google Scholar 

  41. PETERSON, S.C. 1986. Breakdown products of cyanogenesis. Repellency and toxicity to predatory ants. Naturwiss. 73: 627–628.

    Article  CAS  Google Scholar 

  42. SELMAR, D., LIEBEREI, R., BIEHL, B., CONN, E.E. 1989. α-Hydroxynitrile Lyase in Hevea brasiliensis and its Significance for Rapid Cyanogenesis. Physiol. Plantarum 75: 97–101.

    Article  CAS  Google Scholar 

  43. OXTOBY, E., DUNN, M.A., PANCORO, A., HUGHES, M.A. 1991. Nucleotide and derived amino acid sequence of the cyanogenic β-glucosidase (linamarase) from white clover (Trifolium repens L.). Plant Molec. Biol. 17(2): 209–220.

    Article  CAS  Google Scholar 

  44. HUGHES, M.A., BROWN, K., PANCORO, A., MURRAY, B.S., OXTOBY, E., HUGHES, J. 1992. A molecular and biochemical analysis of the structure of the cyanogenic β-glucosidase (linamarase) from cassava (Manihot esculenta Cranz) Arch. Biochem. Biophys. 295(2): 273–279.

    Article  PubMed  CAS  Google Scholar 

  45. CICEK, M., ESEN, A. 1995. Cloning and sequencing of a cDNA coding for β-glucosidase (dhurrinase) from Sorghum bicolor (L) Moench. Plant Physiol. 109(4): 1497.

    Article  Google Scholar 

  46. CHENG, I.P., POULTON, J.E. 1993. Cloning of cDNA of Prunus serotina (R)-(+)-mandelonitrile lyase and identification of a putative FAD-binding site. Plant Cell Physiol. 34(7): 1139–1143.

    CAS  Google Scholar 

  47. HUGHES, J., CARVALHO, F.J.P., HUGHES, M.A. 1994. Purification, characterization, and cloning of alpha-hydroxynitrile lyase from cassava (Manihot esculenta Crantz). Arch. Biochem. Biophys. 311(2): 496–502.

    Article  PubMed  CAS  Google Scholar 

  48. WAJANT H., MUNDRY, K.W., PFIZENMAIER, K. 1994. Molecular cloning of hydroxynitrile lyase from Sorghum bicolor (L.). Homologies to serine carboxypeptidases. Plant Molec. Biol. 26(2): 735–746.

    Article  CAS  Google Scholar 

  49. HASSLACHER, M., SCHALL, M., HAYN, M., GRIENGL, H., KOHLWEIN, S.D., SCHWALB, H. 1996. Molecular cloning of the full-length cDNA of (S)-hydroxynitrile lyase from Hevea brasiliensis. J. Biol. Chem. 271: 5884–5891.

    Article  PubMed  CAS  Google Scholar 

  50. TRUMMLER, K., WAJANT, H. 1997. A novel class of hydroxynitrile lyases. J. Biol. Chem. 272(8): 4770–4774.

    Article  PubMed  CAS  Google Scholar 

  51. HU, Z., POULTON, J.E. 1997. Sequencing, genomic organization, and preliminary promotor analysis of black cherry (R)-(+)-mandelonitrile lyase gene. Plant Physiol. 115(4): 1359–1369.

    Article  PubMed  CAS  Google Scholar 

  52. ERB, N., ZINSMEISTER, H.D., LEHMANN, G., MICHELY, D. 1981. Der Blausäuregehalt von Getreidearten gemäßigter Klimazonen. Z. Lebensm. Unters. Forsch. 173:176–179.

    Article  CAS  Google Scholar 

  53. MONTGOMERY, R.D. 1969. Cyanogens, pp. 143–157 in Toxic Constituents of Plant Foodstuffs (I.E. Liener, ed.), Academic Press, London.

    Google Scholar 

  54. NARTEY, F 1968. Studies on cassava, Manihot usitatissimum. Phytochemistry 20: 1311–1314.

    Article  Google Scholar 

  55. NARTEY, F 1981. Cyanogenesis in tropical feeds and foodstuffs, pp. 115–132 in Cyanide in Biology (B. Vennesland, E.E. Conn, C.J. Knowles, J. Westley, F. Wissing, eds.), Academic Press, London.

    Google Scholar 

  56. OKE, O.L. 1994. Eliminating cyanogens from cassava through processing: Technology and tradition. Acta Horticulture 375: 163–174.

    CAS  Google Scholar 

  57. ZINSMEISTER, H.D., ERB, N. 1981. Cyanogene Glycoside in Getreidearten verschiedener Klimazonen. Lebensmittelchem. u. gerichtl Chem. 35: 55–59.

    Google Scholar 

  58. ZINSMEISTER, H.D., ERB, N., LEHMANN, G. 1980. Der Blausäuregehalt tropischer und subtropischer Getreideaten. Z. Lebensm. Unters. Forsch. 171: 170–173.

    Article  CAS  Google Scholar 

  59. NAHRSTEDT, A. 1971. Zur Cyanogenese von Prunus avium. Phytochemistry 11: 3121–3126.

    Article  Google Scholar 

  60. LANG, I. 1990 Cyanogene Verbindungen in Nahrungs- Gewürz- und Genußmittelpflanzen sowie in Nahrungs- und Genußmitteln. Masters thesis, University of Saarbrücken.

    Google Scholar 

  61. TANAKA, O., CLELAND, C., BEN-TAL, Y. 1983. Effect of ferricyanide, ferrocyanide and KCN on growth and flowering on the short-day plant Lemna paucicostata. Plant and Cell Physiology 24(4): 705–711.

    CAS  Google Scholar 

  62. GASSNER, G., Heuer, W. 1927. Praktische Anleitung zum Frühtreiben von Pflanzen mittels Blausäure. Verlagsbuchhandlung Paul Parey, Berlin.

    Google Scholar 

  63. YANG, S.F., HOFFMANN, N.E. 1984. Ethylene biosynthesis and its regulation in higher plants. Ann. Rev. Pl. Physiol. 35: 155–189.

    Article  CAS  Google Scholar 

  64. LEHMANN, G., ZINSMEISTER, H.D., ERB, N., NEUNHOEFFER, O. 1979. Über den Blausäuregehalt von Getreiden und Getreideprodukten Z. Ernährungswiss. 18: 16–22.

    Article  CAS  Google Scholar 

  65. WESTLEY, J. 1981. Cyanide and sulfane sulfur, pp. 61–76 in Cyanide in Biology (B. Vennesland, E.E. Conn, C.J. Knowles, J. Westley, F. Wissing, eds.), Academic Press, London.

    Google Scholar 

  66. ROSLING, H. 1994. Measuring effects in humans of dietary cyanide exposure from cassava. Acta Horticulture 375: 271–283.

    CAS  Google Scholar 

  67. MACKENZIE, W.M., CLYNE, A.H., MACDONALD, L.S. 1990. Ethyl carbamate formation in grain-based spirits: Part II. The identification and determination of cyanide related species involved in ethyl carbamate formation in scotch whisky. J. Inst. Brewing 96(4): 223–232.

    CAS  Google Scholar 

  68. COOK, R., MCGAIG, N., MCMILLAN, J.M.B., LUMSDEN, W.B. 1990. Ethyl caramate formation in grain-based spirits: Part III. The primary source. J. Inst. Brewing 96(4): 233–244.

    CAS  Google Scholar 

  69. BAUDOIN, J.P., BARTHELEMY, J.P., NDUNGO, V 1991. Variability of cyanide contents in the primary and secondary genepools of the lima bean, Phaseolous lunatus L. Plant Genetic Resources Newsletter 85: 5–9.

    Google Scholar 

  70. SCHILCHER, H., WILKENS-SAUTER, M. 1986. Quantitative Bestimmung cyanogener Glycoside in Linum usitatissimum mit Hilfe der HPLC. Fette, Seifen, Anstriche 8: 287–290.

    Article  Google Scholar 

  71. DUFOUR, D.L. 1994. Cassava in Amazonia: Lessons in utilization and safety from native people. Acta Horticulture 375: 175–182.

    CAS  Google Scholar 

  72. ESSERS, S. 1995. Removal of cyanogens from cassava roots. CIP-DATA Koninklijke Bibliothetheek, Den Haag, 131 p.

    Google Scholar 

  73. DELANGE, F., EKPECHI, L.O., ROSLING, H. 1994. Cassava cyanogenesis and iodine deficiency disorders. Acta Horticulture 375: 289–293.

    CAS  Google Scholar 

  74. TYLLESKÄR  aa 1994. The association between cassava and the paralytic disease konzo. Acta Horticulture 375: 331–339.

    Google Scholar 

  75. SPENCER, P. 1994. Human consumption of plant material with neuro-toxic potential. Acta Horticulture 375: 341–348.

    Google Scholar 

  76. AKANJI, A.O. 1994. Cassava intake and the risk of diabetes in humans. Acta Horticulture 375: 349–359.

    CAS  Google Scholar 

  77. SUDARESAN, S., NAMBISAN, B., ESWARIAMMA, C.S. 1987. Bitterness in cassava in relation to cyanogen content. Indian J. Agric. Sci. B57: 37–40.

    Google Scholar 

  78. BOKANGA, M. 1994. Distribution of cyanogenic potential in cassava germplasm. Acta Horticulture 375: 117–123.

    CAS  Google Scholar 

  79. NYE, M.M. 1991. The mis-measure of manioc (Manihot esculenta). Econ. Bot. 45(1): 47–57.

    Article  Google Scholar 

  80. PEREIRA, J.F., SEIGLER, D.S., SPLITTSTOESSER, W.E. 1981. Cyanogenesis in sweet and bitter cultivars of cassava. Hortscience 16: 776–777.

    CAS  Google Scholar 

  81. KING, N.L.R., BRADBURY, J.H. 1995. Bitterness of cassava: Identification of a new apiosyl glucoside and other compounds that affect its bitter-taste. J. Sci. Food Agric. 68(2): 223–230.

    Article  CAS  Google Scholar 

  82. DU, L., BOKANGA, M., MØLLER, B.L., HALKER, B.A. 1995. The biosynthesis of cyanogenic glucosides in roots of cassava. Phytochemistry 39(2): 323–326.

    Article  CAS  Google Scholar 

  83. BEDIAKO, M.K.B., TAPPER, B.A., PRITCHARD, G.G. 1981. Metabolism, synthetic site, and translocation of cyanogenic glycosides in cassava, pp. 143–148 in Tropical Root Crops: Research strategies for the 1980s (E.R. Terry, K.A. Oduro, F. Caveness, eds.), International Development Research Centre, Ottawa, Canada.

    Google Scholar 

  84. MAKAME, M., AKORODA, M.O., HAHM, S.K. 1987. Effects of reciprocal stem grafts on translocation in cassava. J. Agric. Sci. Camb. 109: 605–608.

    Article  Google Scholar 

  85. DEBRUIJN, G.H. 1973. The cyanogenic character of cassava (Manihot esculenta) pp. 43–48 in Chronic Cassava Toxicity (B. Nestel, R. Maclntyre, eds.), International Development Research Centre, Ottawa, Canada.

    Google Scholar 

  86. SELMAR, D. 1994. Translocation of cyanogenic glucosides in cassava. Acta Horticulture 375: 61–67.

    CAS  Google Scholar 

  87. NARTEY, F. 1969. Studies on cassava, Manihot usitatissimum, II. Plant Physiol. 22: 1085–1096.

    Article  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Editor information

Editors and Affiliations

Rights and permissions

Reprints and permissions

Copyright information

© 1999 Springer Science+Business Media New York

About this chapter

Cite this chapter

Selmar, D. (1999). Cyanide in Foods. In: Romeo, J.T. (eds) Phytochemicals in Human Health Protection, Nutrition, and Plant Defense. Recent Advances in Phytochemistry, vol 33. Springer, Boston, MA. https://doi.org/10.1007/978-1-4615-4689-4_14

Download citation

  • DOI: https://doi.org/10.1007/978-1-4615-4689-4_14

  • Publisher Name: Springer, Boston, MA

  • Print ISBN: 978-1-4613-7123-6

  • Online ISBN: 978-1-4615-4689-4

  • eBook Packages: Springer Book Archive

Publish with us

Policies and ethics