N -ethyl maleimide

Structural formula
General
Surname	N -ethyl maleimide
other names	1-ethyl-3-pyrroline-2,5-dione NEM
Molecular formula	C 6 H 7 NO 2
Brief description	colorless crystals with a pungent odor
External identifiers / databases
CAS number 128-53-0 EC number 204-892-4 ECHA InfoCard 100.004.449 PubChem 4362 DrugBank DB02967 Wikidata Q292393
properties
Molar mass	125.13 g mol −1
Physical state	firmly
density	0.33 g cm −3
Melting point	43-46 ° C
boiling point	210 ° C
solubility	heavy in water (1 g l −1 at 20 ° C)
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 300-311-314-317 P: 264-280-301 + 310-305 + 351 + 338-310
Toxicological data	25 mg kg −1 ( LD 50 ,  rat ,  oral ) 5 mg kg −1 ( LD 50 ,  mouse ,  ip )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

N -Ethylmaleimide (NEM) is an imide derived from maleic acid . It is used in biochemical experiments to block sulfhydryl groups with which itreacts spontaneouslyat pH values of 6.5 to 7.5. This reaction can be followed by measuring the decrease in light absorption at a wavelength of 300 nm. This canchemically inactivatereagents or proteins that would otherwise interfere with the planned experiments.

Individual evidence

1. ↑ ^{a b c} Data sheet N-Ethylmaleimide from Sigma-Aldrich , accessed on October 22, 2016 ( PDF ).
2. ↑ ^{a b c d e} Entry on N-ethylmaleimide in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .
3. ↑ ^{a b} Entry on N-ethylmaleimide in the ChemIDplus database of the United States National Library of Medicine (NLM)
4. ↑ N -ethylmaleimide from Thermo Scientific .