Ergotoxine alkaloids

The ergotoxine alkaloid mixture also has oxytocic and vasoconstrictor activity but is only employed medicinally as the 9,10-dihydro derivatives dihydroergotoxine (co-dergocrine), a mixture in equal proportions of dihydroergocornine, dihydroergocristine, and the dihydroergocryptines (a- and p- in the ratio 2 1). In the case of these alkaloids, reduction of the double bond appears to reverse the vasoconstrictor effect, and dihydroergotoxine has a cerebral vasodilator activity. The increased blood flow is of benefit in some cases of senility and mild dementia, and helps to improve both mental function and physical performance. 

These properties are still more marked in the case of the hydrogenated derivatives of the ergotoxine alkaloids. A combination of dihydro-... 

Because of the low volatility and thermal instability at high temperatures of the dihydro-ergotoxine alkaloids, Szepesi and Gazdag developed a gas chromatographic method for the separation and identification of these alkaloids (dihydroergocristine, dihydroergokryptine... 

The first reversed-phase separation of ergot alkaloids was reported by Jane and Wheals in connection with the analysis of LSD. Pellicular beads with chemically bonded octadecyl groups were used in combination with methanol - 0.1% aqueous ammonium carbonate (3 2) as mobile phase However, the mobile phase proposed by Vivilecchia et al.6 for the separation of the dihydro-ergotoxine alkaloids on octadecyl columns (acetonitrile - aqueous ammonium carbonate) has been... 

For a specific detection of the ergotoxine alkaloids, Szepesy et al. used a wavelength of 320 nm, for their dihydroderivatives 280 nm. Bethke et al.17 applied simultaneous detection at 280 and 320 nm for ergotamine and its decomposition products. Detection at 241 nm 52... 

Kobel H, Sanglier JJ. Formation of ergotoxine alkaloids by fermentation and attempts to control their biosynthesis. In Hiitter R, Leisinger T, Niiesch J, Wehrli W, eds. Antibiotics and Other Secondary Metabolites. New York Academic Press, 1978, pp 233-242. 

Fig. 4.9) (115). Each component of the ergotoxine alkaloids ccmtains a tripeptide moiety, with two of three amino acids (u-valine and L-proline) being in common in all of the compounds, while the third amino acid differs (115). The ergotoxines 160-163 isolated from natural sources can be hydrogenated to yield the 9,10-dihydroergotoxines 164-167, composed of dihydroergocomine... 

Biosynthesis. In Claviceps purpurea, and presumably also in higher plants, E.a. are biosynthesized from tryptophan and isopentenylpyrophosphate (see Terpenes). Synthesis proceeds via 4-dimethylallyl-tiyptophan, which is converted into the alkaloid chanoclavine (by hydroxylation, methylation, decarboxylation and formation of a new C-C bond). All the other clavine alkaloids and the lysergic acid derivatives are derived from chanoclavine. The peptide moieties of the ergotamine and ergotoxin alkaloids are formed by a multienzyme complex (Fig. 2). E.a. are prepared from the sclerotia of rye, previously inoculated with Claviceps and they are also produced by culture of the fungus on artificial growth media. 

Groger, D. and Johne, S. (1972) Uber den Einbau von Dipeptiden in Ergotoxin-Alkaloide. Experientia, 28, 241-242. 

Szepesi, G., Gazdag, M. and Terdy, L. (1980) Separation of ergotoxine alkaloids by high-performance liquid chromatography on silica./. Chromatogr., 191, 101-108. 

Kobel, H. and Sanglier, J.-J. (1978) Formation of ergotoxine alkaloids by fermentation... 

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