Skip to main content Accessibility help

Pyridazocidin, a new microbial phytotoxin with activity in the Mehler reaction

  • B. Clifford Gerwick (a1), Stephen S. Fields (a2), Paul R. Graupner (a2), James A. Gray (a2), Eleanor L. Chapin (a2), John A. Cleveland (a2) and Dale R. Heim (a2)...


A new phytotoxin, pyridazocidin, was produced in shake-flask cultures of a Streptomyces sp. soil isolate. A combination of solvent partitioning, size-exclusion chromatography, and high-pressure liquid chromatography (HPLC) was used to isolate the material. The structure was assigned based on mass spectroscopy and nuclear magnetic resonance (NMR) experiments. Greenhouse evaluations indicated rapid necrosis and chlorosis of treated weeds, particularly of giant foxtail. Isolated chloroplasts consumed oxygen in the presence of pyridazocidin over a concentration range also inhibiting plant growth. Pyridazocidin represents the first reported natural product that appears to act via reversible oxidation/reduction linked to photosynthetic electron transport.


Corresponding author


Hide All
Ahrens, W. T., ed. 1994. Herbicide Handbook. 7th ed. Champaign, IL: Weed Science Society of America. 352 p.
Amagasa, T., Paul, R. N., Heitholt, J. J., and Duke, S. O. 1994. Physiological effects of cornexisten on Lemna pausicostata . Pestic. Biochem. Physiol. 49: 3752.
Camilleri, P., Bowyer, J. R., Clark, M. T., and O&Neill, P. 1984. Dioxathiadiaza-heteropentalines: new photosystem-I electron acceptors. Biochim. Biophys. Acta 765: 236238.
Cutler, H. G. 1988. Perspectives on discovery of microbial phytotoxins with herbicidal activity. Weed Technol. 2: 525532.
Duke, S. O., Abbas, H. K., Boyette, C. D., and Gohbara, M. 1991. Microbial Compounds with the Potential for Herbicidal Use. Brighton Crop Protection Conference—Weeds, pp. 155164.
Duke., S. O. and Lydon, J. 1987. Herbicides from natural compounds. Weed Technol. 1: 122128.
Fields, S. C., Gerwick, B. C., and Mireles-Lo, L., inventors; DowElanco, assignee. 1995. Hydroxycornexistin. US patent 5,424,278.
Fields, S. C., Graupner, P. R., and Tromiczak, E. G. 1996a. 9-BBN Protected Amino Acids and Their Use in Natural Product Synthesis. Pensacola, FL: 19th Gulf Coast Chemical Conference.
Fields, S. C., Mireles-Lo, L., and Gerwick, B. C. 1996b. Hydroxycornexistin: a new phytotoxin from Paecilomyces variotii . J. Nat. Prod. 59: 698700.
Fischer, H. and Bellus, D. 1983. Phytotoxicants from microorganisms and related compounds. Pestic. Sci. 14: 334346.
Grote, R., Chen, Y., Zeeck, A., Chen, Z., Zähner, H., Mischnick-Lübbecke, P., and König, W. A. 1988. Metabolic products of microorganisms. 243. Pyridazomycin, a new antifungal antibiotic produced by Streptomyces violaceoniges . J. Antibiot. 41: 595601.
Heim, D. R., Cseke, C., Gerwick, B. C., Murdoch, M. G., and Green, S. B. 1995. Hydantocidin: a possible proherbicide inhibiting purine biosynthesis at the site of adenylosuccinate synthetase. Pestic. Biochem. Physiol. 53: 138145.
Nakajima, M., Itoi, K., Takamatsu, Y., et al. 1991. Hydantocidin: a new compound with herbicidal activity from Streptomyces bygroscopicus . J. Antibiot. 44: 293300.
Somerville, C. R. and Ogren, W. L. 1982. Isolation of photorespiration mutants in Arabidopsis thaliana . Pages 129138 in Edelman, G. M., Hallie, R. B., Chera, N-H, eds. Methods in Chloroplast Biology. Amsterdam: Elsevier Science.
Stonard, R. J. and Miller-Wideman, M. A. 1995. Herbicides and plant growth regulators. Pages 285310 in Godfrey, C.R.A., ed. Agrochemicals from Natutal Products. New York: Marcel Dekker.
Summers, L. A. 1980. The Bipyridinium Herbicides. Pages 316319. London: Academic Press.
Walker, D. 1987. The Use of the Oxygen Electrode and Fluorescence Probes in Simple Measurements of Photosynthesis. Pages 106109. West Sussex, Great Britain: Packard Publishing.
Williams, S. T. and Cross, T. 1971. Actinomycetes. Pages 295334 in Booth, C., ed. Methods in Microbiology. New York: Academic Press.



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed