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THE CHEMISTRY OF JUGLONE A DETECTIVE STORY OF UNSOLVED MYSTERY

THE CHEMISTRY OF JUGLONE A DETECTIVE STORY OF UNSOLVED MYSTERY. Juglone: A Natural Herbicide ( Allelopath ). Historical Profile/Toxicity? Isolation Synthesis Mechanism Characterization Recent Studies Future plans Acknowledgement. JUGLONE C 10 H 6 O 3.

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THE CHEMISTRY OF JUGLONE A DETECTIVE STORY OF UNSOLVED MYSTERY

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  1. THE CHEMISTRY OF JUGLONE A DETECTIVE STORY OF UNSOLVED MYSTERY

  2. Juglone: A Natural Herbicide(Allelopath) • Historical Profile/Toxicity? • Isolation • Synthesis • Mechanism • Characterization • Recent Studies • Future plans • Acknowledgement

  3. JUGLONEC10H6O3

  4. 1,4-Naphthalenedione, 5-hydroxy- Formula: C10H6O3 Molecular Weight: 174.15 CAS Registry Number: 481-39-0 Chemical Structure:

  5. Other Names: 1,4-Naphthoquinone, 5-hydroxy-; Akhnot; C.I. Natural Brown 7; C.I. 75500; Iuglon; Juglane; Juglon; Juglone; Nucin; Regianin; Walnut Extract; Yuglon; 5-Hydroxy-1,4-naphthoquinone; 5-Hydroxy-1,4-naphthosemiquinone; 5-Hydroxynaphthoquinone; 8-Hydroxy-1,4-naphthoquinone; Jugnlon; NCI 2323; Oil Red BS; 1,4-Naphthoquinone, 8-hydroxy-; 5-Hydroxy-1,4-naftochinon; Lawsone

  6. Historical Profile of JugloneThe Birth of Allelopathy (1950) • Toxicity of Juglone has been and continues to be an unsolved Problem!

  7. 1925 - Massey reported experiments showing a toxic effect of walnut bark on tomato plants. • 1927 - Schneiderhan reported killing of apple trees near walnuts. • 1950 - Davis reported that isolated Juglone was highly toxic when injected into alfalfa and tomato plants.

  8. 1940 - MacDaniels and Muenscher reported a 3-year greenhouse study showing no toxicity by Juglone on tomato plants, alfalfa, and apple trees. • 1950 - USDA published a press release under the title “Test Clears Walnut Reputation.” claiming no evidence of any toxic effect by Juglone on Tomatoes. Birth of Allelopathy!

  9. 1951 - Brooks studied the controversy for 12 years on 218 species. He confirmed Massey’s earlier work suggesting that the toxicity appeared onlywhen the roots were in contact with each other. • NOTE: Dow Chemical reported that UV light was essential for the secretion of Juglone, which explained the negative toxicity reported by MacDaniels and Muenscher in 1940.

  10. 1975 -An extensive study at Ithaca, New York confirmed the toxicity of Juglone with the following assertions: • Antagonism between walnut and other plants has been observed. • The substance responsible for this antagonism is Juglone. • Root to root contact must exist for toxicity to occur.

  11. 1999 – Recent studies by Boyer at Cornell found the following: • Juglone extract from unripe walnuts can cause a sedative effect in different species of animals. In one study , goldfish, mice, rats, and rabbits all experienced a depressant effect from the juglone. • Rabbits also experienced a rise in ear temperature due to vasodilation. • It also dilated the coronary arteries of rabbits heart. However, juglone does not appear to have any effect on the blood pressure and heart rate of dogs.

  12. When rats were fed juglone, an accumulation of abdominal fluid accompanied by proteins, a loss of fluid from lung tissues, and a decrease in plasma proteins occurred. • There was also an increase in plasma potassium, but not in plasma sodium. These findings suggest that juglone may increase capillary permeability.

  13. Dogs administered juglone intravenously also experienced fluid loss in the lungs. In addition, experimental dogs had an increased hematocrit and blood specific gravity, but a lower plasma specific gravity. • This also gives evidence that juglone is toxic to cell membranes, increasing capillary permeability. • Several studies have been done on horses in an attempt to determine whether or not juglone is the toxic compound in black walnuts that causes laminitis in horses.

  14. A juglone-ethanol solution administered to ponies via a stomach tube resulted in symptoms of mild laminitis in two of four ponies. • Juglone applied topically to horses' forelimbs resulted in increased digital pulses after 3 hours and in increased skin temperatures after five hours.Laminitis and increased hoof temperaturewere not noticed.

  15. Horses receiving juglone intravenously had an anaphylactic type of response. Respiratory rates increased, fluid accumulated in the lungs, but the ponies did not show any signs of laminitis. • An anaphylactic response only occurred in ponies that had previously been exposed to juglone.

  16. In Summary: • The physiological action of juglone and its allelopathic effects are not well understood. • Research has shown that juglone may alter the normal oxygen uptake of mitochondria and may also impair photosynthesis which would lead to decreased growth rates of the effected plants.

  17. Our ResearchI: Isolation of Juglone • Isolation was done by extracting crushed hull with petroleum ether. Recrystallization produced orange needles with MP of 153-159 C

  18. II: Synthesis of Juglone • Sodium dichromate in water is carefully added to conc. sulfuric acid. To this slurry, add 1,5-dihydroxynaphthalene. The mixture is then heated to no more than 50C for thirty min. Crude product is recrystallized from hexane. Yellow-orange needles were produced with MP 148-153C.

  19. III: Spectral Characterization

  20. H-NMRParameter Parts Per Million Hz D (A) 7.579 D (B) 7.601 D (C) 7.243 D (D) 11.834 J (A,B) 7.56 J (A,C) 1.19 J (A,D) 0.0 J (B,C) 8.44 J (B,D) 0.37 J (C,D) 0.0 D (E) 6.917

  21. C-13 NMR Carbon Assignment Integration Parts Per Million 1 309 190.26 2 258 184.19 3 608 161.45 4 845 139.57 5 1000 138.62 6 938 136.54 7 454 131.78 8 814 124.48 9 969 119.13 10 381 114.97

  22. Juglone

  23. Molecular Mass Fragments

  24. Current Goals: Summer 2003 - Examine the allelopathy of Juglone on Tomato Plants • Decide most effective solvent • Decide range of effective concentrations of Juglone • Design and set-up experiment • Collect data • Test allelopathy on Space and Earth Tomatoes

  25. Progress 1. That ethanol is the ideal solvent of choice. 2. That Juglone concentrations of 5, 10, 50, 100, and 250, 500, and 1000 μM were adequate. 3. Our team of four students tried to duplicate their data with inconclusive results. 4. Work on these goals shall resume Spring and Summer 2005 (any interested students?) (Dr. Angie Hejl working with Mr. Sebastian Ribi, a graduate student from Switzerland”

  26. Recent Studies • Krajci, W. M., and Lynch, D. L. (1978). The inhibition of various micro-organisms by crude walnut hull extracts and Juglone. Microbios Letters. 4, 175-181

  27. Craton, D. W., and Williams, R. D. (1980). Juglone Dermatitis: Allergy or Irritant? Indiana Academy of Science. 90: 98-102

  28. Clark, A. M., Jurgens, T. A., and Hufford, C. D. (1990). Antimicrobial Activity of Juglone. Phytotherapy Research. 4, 11-14.

  29. Galey, F. D., Whiteley, H. E., Goetz, T. E., Kuenstler, A. R. Davis, C. A., and Beasley V. R. (1991). Black walnut (Juglans nigra) Toxicosis: A Model for Equine Laminitis. J. Comp. Path. 104, 313-326.

  30. Acknowledgements University of St. Francis (USF) Kelly Wentz-Hunter (Ph.D.) Sherry Litko (BS, USF) Kerri Banser (BS, USF) Kristina Taylor (BS, USF) Brian Herbst (Senior at USF) Hadyn Hollister (Senior at USF) NASA Tomato Space Program

  31. Thank you Dr. Salim M. Diab Professor of Chemistry University of St. Francis Lewis University Joliet, Illinois 60435 sdiab@stfrancis.edu 815-740-3855 2004

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