Pemetrexed (disodium hemipenta hydrate) (Standard) is the analytical standard of Pemetrexed (disodium hemipenta hydrate). This product is intended for research and analytical applications. Pemetrexed disodium hemipenta hydrate is a novel antifolate, the Ki values of the pentaglutamate of LY231514 are 1.3, 7.2, and 65 nM for inhibits thymidylate synthase (TS), dihydrofolate reductase (DHFR), and glycinamide ribonucleotide formyltransferase (GARFT), respectively.