Research Paper | Published:

29–Fluorophytosterols: Novel Pro–Insecticides which Cause Death by Dealkylation

Bio/Technology volume 1, pages 6265 (1983) | Download Citation



The 29–fluorophytosterols, members of a new class of selective pro–insecticides, have been synthesized and examined in vivo in tobacco hornworms. Dealkylation at C–24 of the steroid side chain by insects releases the latent poison fluoroacetate. Vertebrates lack this dealkylation pathway and should be incapable of the lethal synthesis. The 29–fluorophytosterols cause dose–dependent reductions in growth rate, maximum weight, and survival when fed at 1 to 100 ppm to Manduca sexta. Larval steroid composition is unaffected. Similar biological effects were observed when fluorocitrate and its metabolic precursors were fed to horn worms. The effects of five related 29–monofluorosterols show that the 22,23– double bond increases toxicity dramatically, making 29–fluorostigmasterol 100 fold more active than 29–fluorositosterol.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1.

    and 1983. Comparative sterol metabolism in insects. In: Metabolic Aspects of Lipid Nutrition in Insects, T.E. Mittler and R.H. Dadd, eds., pp. 1–16. Boulder: Westview Press.

  2. 2.

    , , , and 1983. Sterol metabolism of the silkworm Bombyx mori . In: Metabolic Aspects of Lipid Nutrition in Insects, T.E. Mittler and R.H. Dadd, eds., pp. 17–26. Boulder: Westview Press.

  3. 3.

    1982. Sterols and insects. In: Cholesterol Systems in Insects and Animals, J.H. Dupont, ed., pp. 1–50, Boca Raton: CRC Press.

  4. 4.

    , , and 1978. Insect sieriod metabolism. Lipids 13: 742–753.

  5. 5.

    , and 1974. Insect control of the future: operational and policy aspects. Science 186: 596–602.

  6. 6.

    1982. New concepts and trends in pesticide chemistry. J. Agric. Food Chem. 30: 201–215.

  7. 7.

    1979. Comparative biochemistry and drug design for infectious disease. Science 205: 964–971.

  8. 8.

    1982. Suicide substrates: mechanism-based enzyme inactivators. Tetrahedron 38: 871–909.

  9. 9.

    1957. Mechanism of the toxicity of the active constituent of Dichapetalum cymosum and related compounds. In: Adv. Enzymol. 18: 113–159.

  10. 10.

    1976. Fluorocarboxylic acids as enzymatic and metabolic probes. In: Biochemistry Involving Carbon-Fluorine Bonds. R. Filler, ed. pp. 1–22. Washington: American Chemical Society.

  11. 11.

    , and 1978. Molecular toxicology of (–)-erythro-fluorocitrate: selective inhibition of citrate transport in mitochondria and the binding of fluorocitrate to mitochondrial proteins. Molec. Pharmacol. 14: 172–184.

  12. 12.

    1959. Toxic Aliphatic Fluorine Compounds. London: Elsevier Press.

  13. 13.

    , and 1981. Fluorolipids as targeted termitiddes and biochemical probes. J. Agric. Food Chem. 29: 1023–1027.

  14. 14.

    , and 1981. Synthesis of fluorolipids: 1-0-aIkyl-2,3-0-diacylglycerols as targeted insecticides. J. Agric. Food Chem. 29: 1018–1022.

  15. 15.

    , , , and 1983. Comparative toxicity of fluorinated lipids and their evaluation as bait block toxicants for the control of Reticulitermes spp. (Isoptera: Rhinotermitidae) J. Econ. Entomol. (in press)

  16. 16.

    and 1977. Biochemistry of Steroids and Other Isopentenoids. Baltimore: University Park Press.

  17. 17.

    1981. Cholesterol Systems in Insects and Animals, Boca Raton: CRC Press.

  18. 18.

    1969. The carbon-fluorine bond in compounds of biological interest. Science 164: 1123–1129.

  19. 19.

    1978. Introduction of fluorine into organic molecules: why and how. Tetrahedron 34: 3–17.

  20. 20.

    and 1983. Synthesis of 29-fluorophytosterols: a novel class of insect-activated selective poisons. Tetrahedron Lett. (in press).

  21. 21.

    and 1982. Side chain modified sterols as probes into insect molting hormone metabolism. I: Synthesis of monofluorophytosterols. Tetrahedron Lett. 23: 3043–3046.

  22. 22.

    , and 1983. Side chain modified sterols as probes into insect molting hormone metabolism. II: Synthesis of monofluorocholesterols. Steroids. (in press).

  23. 23.

    , and 1981. Structural requirement of the sterol side chain for the silkworm growth and development. Steroids 38: 2841–2847.

Download references

Author information

Author notes

    • Glenn D. Prestwich

    Fellow of the Alfred P. Sloan Foundation (1981–85) and Camille and Henry Dreyfus Teacher-Scholar (1981–86), to whom correspondence should be addressed.


  1. Department of Chemistry, State University of New York, Stony Brook, NY 11794

    • Glenn D. Prestwich
    • , Apurba K. Gayen
    • , Seloka Phirwa
    •  & Toni B. Kline


  1. Search for Glenn D. Prestwich in:

  2. Search for Apurba K. Gayen in:

  3. Search for Seloka Phirwa in:

  4. Search for Toni B. Kline in:

About this article

Publication history





Further reading