2-(1-Hydroxyethyl)thiamine pyrophosphate 20319-27-1 Hydroxyethylthiamin pyrophosphate Ohet-tpp Thiazolium, 3-((4-amino-2-methyl-5-pyrimidinyl)methyl)-2-(1-hydroxyethyl)-4-methyl-5-(4,6,6-trihydroxy-3,5-dioxa-4,6-diphosphahex-1-yl)-, chloride, P,P'-dioxide