Gramine

Chembox new
Name = Gramine
IUPACName = 3-(dimethylamino
methyl)-indole
ImageFile = Gramine Structure.png ImageName = Chemical structure of gramine
Section1 = Chembox Identifiers
CASNo = 87-52-5
SMILES = CN(C)CC2=CN
C1=CC=CC=C12
Section2 = Chembox Properties
Formula = C₁₁H₁₄N₂
MolarMass = 174.24 g/mol
MeltingPt = 138-139 °C
Section7 = Chembox Hazards
NFPA-H = 2
NFPA-R = 0
NFPA-F = 1

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.Ref|1

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 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",Ref|2 silver maple,Ref|3 "Hordeum", and "Phalaris" plant species.

ynthesis

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.