Monocrotaline

Structural formula
General
Surname	Monocrotaline
other names	Crotaline
Molecular formula	C 16 H 23 NO 6
Brief description	beige solid
External identifiers / databases
CAS number 315-22-0 EC number 628-506-2 ECHA InfoCard 100.156.772 PubChem 9415 Wikidata Q27107379
properties
Molar mass	325.36 g mol −1
Physical state	firmly
Melting point	204 ° C (decomposition)
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 301-351 P: 281-301 + 310
Toxicological data	66 mg kg −1 ( LD 50 ,  rat ,  oral )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Monocrotaline is an alkaloid and, due to its structure, belongs to the group of pyrrolizidine alkaloids . It is of vegetable origin and poisonous.

Occurrence

Crotalaria spectabilis

Monocrotaline occurs in some species of the genus Crotalaria ( butterflies ); for example in the seeds of Crotalaria spectabilis and Crotalaria mucronata . There it serves to ward off predators, but it can also poison farm animals such as cattle.

The larvae of the butterfly Utetheisa ornatrix from the bear moth family feed almost exclusively on Crotalaria seeds and accumulate monocrotaline in their bodies. In this way, they are protected from predators such as spiders for the rest of their life (even after pupation as a butterfly).

structure

Monocrotaline is one of the retronecines and forms an eleven-membered macrocycle from the necine backbone and variously substituted pentanedioic acids . Further examples of the 30 or so known representatives of this structural pattern are Spectabilin and Grahamin .

Individual evidence

1. ↑ ^{a b c d e f} Data sheet Monocrotaline, analytical standard at Sigma-Aldrich , accessed on June 4, 2017 ( PDF ).
2. ↑ Entry on monocrotaline. In: Römpp Online . Georg Thieme Verlag, accessed on June 4, 2017.