Gramine encyclopedia topics

Gramine

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1 reference results for: Gramine

Wikipedia

Gramine (also called donaxine) is a naturally occurring indole alkaloid present in several plant species. Gramine may play a defensive role in these plants, since it is toxic to many organisms.

Uses

Gramine is used mostly in synthetic organic chemistry as a starting material for tryptophan syntheses.

All reactions of gramine follow the same general reaction scheme. Gramine is reacted with a strong electrophile, such as methyl iodide, to form the quaternary ammonium salt 2. The ammonium salt will undergo a Hofmann elimination or retro-Michael addition to give the very active intermediate 3, which can accept a wide range of nucleophiles to give the desired product 4.

Biology

Gramine has been found in the Arundo, silver maple, Hordeum, and Phalaris plant species.

Synthesis

Despite being widely available in several plant species, gramine is far easier to synthesize directly from indole via a Mannich reaction with dimethylamine and formaldehyde.

References

Corcuera, L. J.; Biochemical basis of the resistance of the barley to aphids. Phytochemistry 1993, 33, 741-747.
Orechoff; Norkina; Ber. 1935, 68, 670.
Pachter et al. J. Org. Chem. 1959, 24, 1285.