3-Ethyl-2-[2-[[3-(2-hydroxy-3-sulfonatopropyl)-5-methylbenzothiazol-2(3H)-ylidene]methyl]-1-butenyl]-5,6-dimethylbenzothiazolium

3-ethyl-2-[2-[[3-(2-hydroxy-3-sulphonatopropyl)-5-methyl-3H-benzothiazol-2-ylidene]methyl]but-1-enyl]-5,6-dimethylbenzothiazolium