title: ESI-Mass spectrometric and HPLC elucidation of a new ergot alkaloid from perennial ryegrass hay silage associated with bovine reproductive problems.
abstract: This case report involves four dairies in the Willamette Valley, Oregon, which experienced reproductive problems associated with the presence of a large, previously unidentified, peak eluting at 5 min in a standard ergovaline high-performance liquid chromatography assay of perennial ryegrass silage fed to those animals. Mycotoxin analysis of the silage was negative, as was serological screening of the herds for infectious bovine rhinotracheitis, bovine diarrhea virus and Leptospirosis, including culturing of urine for Leptospira hardjo hardjobovis. Prolactin concentrations were low in most cattle, consistent with ingestion of ergot alkaloids. We believe that this peak represents a novel ergot alkaloid-related compound due to its extractability with Ergosil, its detectability due to fluorescence, and its chromatographic retention between ergovaline (mw = 533) and ergotamine (mw = 581). Its molecular weight was calculated as 570 owing to the predominance of a m/z 593.5 ion in the full scan ESI(+)MS and its deduced tendency to complex with Na(+) (as m/z 593) or K(+) (as m/z 609) ions. We offer rationales for elucidation of the structure of this compound, with the closest starting point comprising an m.w. of 566-a fructofuranosyl-(2-1)-O-beta-D-fructofuranoside derivative of 6,7-secoergoline from Claviceps fusiformis. This m.w. requires modifications, such as reduction of two double bonds in the secoergoline component to give the target 570 m.w. Despite the lack of a definitive structure, the analysis herein provides a starting point for eventual elucidation of this apparently new ergot alkaloid, and to guide and encourage further investigation as to its association with endophyte toxicosis in livestock.
authors.affiliation: Michigan State University, Diagnostic Center for Population & Animal Health, Lansing, Michigan 48910, USA. LehnerA@dcpah.msu.edu
authors.forename: Andreas F
authors.initials: AF
authors.lastname: Lehner
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Duringer
authors.forename: Charles T
authors.initials: CT
authors.lastname: Estill
authors.forename: Thomas
authors.initials: T
authors.lastname: Tobin
authors.forename: A Morrie
authors.initials: AM
authors.lastname: Craig
mesh_terms: D000034:Abortion, Veterinary / Q000139:chemically induced; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000139:chemically induced; D002851:Chromatography, High Pressure Liquid; D003612:Dairying; D004876:Ergot Alkaloids / Q000737:chemistry* / Q000633:toxicity*; D005260:Female; D007247:Infertility, Female / Q000139:chemically induced / Q000662:veterinary; D008129:Lolium / Q000737:chemistry*; D008672:Metals, Alkali; D015394:Molecular Structure; D011247:Pregnancy; D012820:Silage / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D004876:Ergot Alkaloids; D008672:Metals, Alkali