1,1′-Ethylidenebis
1,1′-Ethylidenebis[L-tryptophan] is an impurity in the synthesis of L-tryptophan. 1,1′-Ethylidenebis[L-tryptophan] promotes the proliferation of eosinophilic leukemia cells, induces the release of eosinophil cationic protein from eosinophils, and stimulates T cells to produce IL-5. 1,1′-Ethylidenebis[L-tryptophan] (40 ug/kg) can induce fascia thickening, mast cell infiltration, and fibrosis in adipose and subcutaneous muscle tissues in mice. 1,1′-Ethylidenebis[L-tryptophan] can be used in immunology and inflammation research[3].