Title: THE CHEMISTRY OF JUGLONE A DETECTIVE STORY OF UNSOLVED
1- THE CHEMISTRY OF JUGLONE
- A DETECTIVE STORY
- OF
- UNSOLVED MYSTERY
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4Juglone A Natural Herbicide(Allelopath)
- Historical Profile/Toxicity?
- Isolation
- Synthesis
- Mechanism
- Characterization
- Recent Studies
- Future plans
- Acknowledgement
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7JUGLONEC10H6O3
81,4-Naphthalenedione, 5-hydroxy- Formula
C10H6O3 Molecular Weight 174.15 CAS
Registry Number 481-39-0 Chemical
Structure
9Other 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-naphth
osemiquinone 5-Hydroxynaphthoquinone
8-Hydroxy-1,4-naphthoquinone Jugnlon NCI 2323
Oil Red BS 1,4-Naphthoquinone, 8-hydroxy-
5-Hydroxy-1,4-naftochinon Lawsone
10Historical Profile of JugloneThe Birth of
Allelopathy (1950)
- Toxicity of Juglone has been and continues to
be an unsolved Problem!
11- 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.
12- 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!
13- 1951 - Brooks studied the controversy for 12
years on 218 species. He confirmed Masseys
earlier work suggesting that the toxicity
appeared only when 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.
14- 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.
15- 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.
16- 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.
17- 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.
18- 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
temperature were not noticed.
19- 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.
20- 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.
21Our ResearchI Isolation of Juglone
- Isolation was done by extracting crushed hull
with petroleum ether. Recrystallization produced
orange needles with MP of 153-159 C
22II 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.
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28III Spectral Characterization
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31 H-NMR Parameter
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
32C-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
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35Juglone
36Molecular Mass Fragments
37Current 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
38Progress
- 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 -
-
39Recent 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
40- Craton, D. W., and Williams, R. D. (1980).
Juglone Dermatitis Allergy or Irritant? Indiana
Academy of Science. 90 98-102
41- Clark, A. M., Jurgens, T. A., and Hufford, C. D.
(1990). Antimicrobial Activity of Juglone.
Phytotherapy Research. 4, 11-14.
42- 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.
43Acknowledgements
- 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
44- Thank you
- Dr. Salim M. Diab
- Professor of Chemistry
- University of St. Francis
- Lewis University
- Joliet, Illinois 60435
- sdiab_at_stfrancis.edu
- 815-740-3855
- 2004
-