(E) -Crotonic acid

NSC 8751 (trans-2-Butenoic acid; trans-Crotonic acid) is an unsaturated carboxylic acid compound containing α, β-unsaturated carboxylic acid groups. NSC 8751 is one of the important analogs for evaluating the safety of fragrance ingredients and is used to evaluate the toxicological properties of compounds with similar structures. When NSC 8751 is applied to local lymph nodes, a 50% concentration does not cause skin sensitization. Structural analogs of NSC 8751 have been shown to be non-genotoxic. trans-Crotonic acid can be used in the preparation of cosmetics and food additives[1][2].