<prompt> Apa from occurring in nucleic acids, pyrimidines are also found inTheophyllineTheobromineFlavin mononucleotideThiamine  <response>: Thiamin vitamin B1 consists of two components: the pyrimidine moiety 4-amino-5-hydroxymethyl-2-methylpyridine and the thiazole moiety 5-2-hydroxyethyl-4-methyl thiazole.The thiazole and pyrimidine moieties are biosynthesized separately and then combined to form ThMP by the action of thiamine-phosphate synthase 