Tall fescue seeds, endophyte-infected

Zhang Q, Spiers DE, Rottinghaus GE, Gamer GB. Thermoregulatory effects of ergo valine isolated from endophyte-infected tall fescue seed on rats. J Agric Food Chem 42 954-958, 1994. 

Zavos PM, Varney DR, Jackson JA Jr, Hemken RW, Siegel MR, Bush LP. Lactation in mice fed endophyte-infected tall fescue seed. Theriogenology 30 865-875, 1988. 

Preparation of sample. Although the endophyte infects the whole fescue plant, seed is a rich source of both loline-type and ergot-type alkaloids (7,8), and presents fewer isolation problems. Endophyte-infected tall fescue seed (Lambert Seed Co., Camden, AL) was defatted with hexane (750 ml per 500 g seed), air-dried, ground in a milling machine to 2 mm mesh, and extracted with methanol (3x, 1500 mL). The methanol extract was concentrated in vacuo approx. 50-fold, to 90 mL, and diluted with 1% aqueous citric acid (500 mL). 

Although sample is normally injected into a countercurrent chromatograph when the mobile phase is initially pumped into the column (12-15), it was found that better retention of stationary phase, a more stable absorbencies baseline, and better resolution of peaks resulted when samples were injected after a 1-hour equilibration period. Unstable baselines were observed during the time in which effluent changed from stationary phase to mobile phase however, baselines stabilized by the time the first sample component appeared in the effluent. An alkaloid extract from endophyte-infected tall fescue seed prepared by a series of acid/base extractions was injected into the countercurrent chromatograph, rather than a crude ethanolic seed extract, because injection of the latter resulted in emulsions. When emulsions were formed, the stationary phase was not retained and separations were unsuccessful. Attempts to process more than 1 g of alkaloid concentrate per injection resulted in reduced resolution of sample components. The optimum flow-rate was 2.2 mL/min. 

A typical countercurrent chromatogram of an alkaloid extract from endophyte-infected tall fescue seed is shown in Figure 3. Two curves are superimposed the solid line represents mg of loline-t)rpe alkaloids determined by GC analysis, and the dotted line represents absorbencies at 312 nm, which is characteristic of... 

Made] CW, Clay K (1991) Avian seed preference and weight loss experiments the effect of fungal endophyte-infected tall fescue seeds. Oecologia (Berlin) 88 296-302... 

Figure 4.3. Typical Capillary Gas Chromatographic Analysis of An Extract of Endophyte-Infected Tall Fescue Seed.

Capillary GC analysis of a typical fescue seed extract is shown in Figure 4.3. Although small peaks corresponding closely in retention time to 4,3, and 10 are often observed, mass spectral analysis revealed that the fragmentation patterns of these substances did not contain the m/z 82 ion characteristic of loline and its derivatives. The most common lolines found in endophyte-infected tall fescue are 6 and 9 along with lesser amounts of 7 and 8. 

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