¹³C₁₇-Mycophenolic acid is intended for use as an internal standard for the quantification of mycophenolic acid by GC- or LC-MS. Mycophenolic acid is an immunosuppressive microbial metabolite that has been found inP. brevicompactum.^1,2It is also an active metabolite of mycophenolate mofetil that is formedviacarboxylesterase 1 (CES1) and CES2.³Mycophenolic acid is an inhibitor of IMP dehydrogenase (IMPDH) type I and type II (IC₅₀s = 32 and 11 nM, respectively, in cell-free assays) and inhibits DNA synthesis in L strain mouse fibroblasts when used at concentrations ranging from 0.1 to 10 µg/ml.^4,5It is active against several strains ofC. albicans,C. parakrusei,C. tropicalis, andC. neoformans(MICs = 3.9-31.25 µg/ml), as well as various strains ofS. aureus(MICs = 31.25-125 µg/ml).²Mycophenolic acid (150 mg/kg) reduces splenomegaly in a mouse model of Friend virus-induced leukemia.⁶It decreases the number of hemolytic plaque forming cells isolated from the spleen of mice immunized with sheep red blood cells (RBCs) when administered at doses ranging from 60 to 240 mg/kg.¹Formulations containing mycophenolic acid have been used as immunosuppressive agents in the prevention of organ transplant rejection.

1.Mitsui, A., and Suzuki, S.Immunosuppressive effect of mycophenolic acidJ. Antibiot. (Tokyo)22(8)358-363(1969) 2.Noto, T., Sawada, M., Ando, K., et al.Some biological properties of mycophenolic acidJ. Antibiot. (Tokyo)22(4)165-169(1969) 3.Fujiyama, N., Miura, M., Kato, S., et al.Involvement of carboxylesterase 1 and 2 in the hydrolysis of mycophenolate mofetilDrug Metab. Dispos.38(12)2210-2217(2010) 4.Watkins, W.J., Chen, J.M., Cho, A., et al.Phosphonic acid-containing analogues of mycophenolic acid as inhibitors of IMPDHBioorg. Med. Chem. Lett.16(13)3479-3483(2006) 5.Franklin, T.J., and Cook, J.M.The inhibition of nucleic acid synthesis by mycophenolic acidBiochem J.113(3)515-524(1969) 6.Williams, R.H., Lively, D.H., DeLong, D.C., et al.Mycophenolic acid: Antiviral and antitumor propertiesJ. Antibiot. (Tokyo)21(7)463-464(1968)