Abstract
When infested with the fungus Rhizoctonia leguminicola, certain forages, e.g., red clover hay, can cause a "slobber syndrome" of varying severity when consumed by ruminants. The causative agent has been presumed to be slaframine [(1S,6S,8aS)-1-acetoxy-6-aminooctahydroindolizine], which is produced by R. leguminicola. In one serious outbreak of the slobber syndrome in horses, the red clover forage involved was carefully examined and found to contain R. leguminicola and slaframine. An identical hay sample is shown here by ion-exchange chromatographic and gas chromatographic-mass spectrometric analysis of appropriate hay extracts to also contain swainsonine [(1S,2R,8R,8aR)-1,2,8-trihydroxyoctahydroindolizine], a potent alpha-mannosidase inhibitor. Swainsonine has previously been isolated from pure cultures of R. leguminicola and from higher plants, namely the Darling pea (Swainsona canescens) and spotted locoweed (Astragalus lentiginosus). Consumption of Darling pea and spotted locoweed by livestock results in a severe neurological condition resembling that observed in hereditary mannosidosis in cattle and humans. Our findings indicate that swainsonine may be viewed as a mycotoxin when present in moldy forages consumed by livestock. The extent to which slaframine and swainsonine mycotoxicosis pose threats to animal husbandry and, indeed, to humans, if these alkaloids were to enter the human food chain, deserves serious consideration.
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- Aust S. D. Effect of slaframine on exocrine gland function. Biochem Pharmacol. 1970 Feb;19(2):427–433. doi: 10.1016/0006-2952(70)90198-x. [DOI] [PubMed] [Google Scholar]
- CRUMP M. H., SMALLEY E. B., HENNING J. N., NICHOLS R. E. MYCOTOXICOSIS IN ANIMALS FED LEGUME HAY INFESTED WITH RHIZOCTONIA LEGUMINICOLA. J Am Vet Med Assoc. 1963 Nov 1;143:996–997. [PubMed] [Google Scholar]
- Dorling P. R., Huxtable C. R., Colegate S. M. Inhibition of lysosomal alpha-mannosidase by swainsonine, an indolizidine alkaloid isolated from Swainsona canescens. Biochem J. 1980 Nov 1;191(2):649–651. doi: 10.1042/bj1910649. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gardiner R. A., Rhinehart K. L., Jr, Snyder J. J., Broquist H. P. Slaframine. Absolute stereochemistry and a revised structure. J Am Chem Soc. 1968 Sep 25;90(20):5639–5640. doi: 10.1021/ja01022a076. [DOI] [PubMed] [Google Scholar]
- Guengerich F. P., Snyder J. J., Broquist H. P. Biosynthesis of slaframine, (1S,6S,8aS)-1-acetoxy-6-aminooctahydroindolizine, a parasympathomimetic alkaloid of fungal origin. I. Pipecolic acid and slaframine biogenesis. Biochemistry. 1973 Oct 9;12(21):4264–4269. doi: 10.1021/bi00745a034. [DOI] [PubMed] [Google Scholar]
- Hagler W. M., Behlow R. F. Salivary syndrome in horses: identification of slaframine in red clover hay. Appl Environ Microbiol. 1981 Dec;42(6):1067–1073. doi: 10.1128/aem.42.6.1067-1073.1981. [DOI] [PMC free article] [PubMed] [Google Scholar]
- James L. F., Hartley W. J. Effects of milk from animals fed locoweed on kittens, calves, and lambs. Am J Vet Res. 1977 Aug;38(8):1263–1265. [PubMed] [Google Scholar]
- Li Y. T. Studies on the glycosidases in jack bean meal. I. Isolation and properties of alpha-mannosidase. J Biol Chem. 1967 Dec 10;242(23):5474–5480. [PubMed] [Google Scholar]
- Molyneux R. J., James L. F. Loco intoxication: indolizidine alkaloids of spotted locoweed (Astragalus lentiginosus). Science. 1982 Apr 9;216(4542):190–191. doi: 10.1126/science.6801763. [DOI] [PubMed] [Google Scholar]
- Tulsiani D. R., Harris T. M., Touster O. Swainsonine inhibits the biosynthesis of complex glycoproteins by inhibition of Golgi mannosidase II. J Biol Chem. 1982 Jul 25;257(14):7936–7939. [PubMed] [Google Scholar]