A Synthetic Approach to Poly-γ-Glutamyl Analogs of Methotrexate

  • James R. Piper
  • John A. Montgomery
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 163)


Methotrexate poly-γ-glutamates bearing two and three glutamate units above that present in methotrexate have been synthesized by extension of a previously described route by which the lower congener bearing one added glutamate unit was synthesized. Key steps in the sequence are the peptide coupling of N-[4-[[(benzyloxy)-carbonyl]methylamino]benzoyl]-L-glutamic acid α-benzyl ester (5) with oligo-γ-L-glutamate benzyl esters, removal of blocking groups by catalytic hydrogenolysis, and introduction of the (2,4-diamino-6-pteridinyl)methyl grouping by alkylation with (6-bromomethyl)-2,4-pteridinediamine hydrobromide. Elaboration of the required oligo-γ-L-glutamate chain was achieved one unit at a time beginning with the coupling of L-glutamic acid dibenyl ester with t-butyloxy-carbonyl-L-glutamic acid α-benzyl ester (7) followed by selective removal of the t-butyloxycarbonyl grouping and another coupling step with 5 or 7 as required. Diphenylphosphoryl azide was used as the coupling reagent in each conversion producing a peptide linkage. Intermediates were obtained in pure form according to thin-layer chromatography and elemental analysis results, and the final target compounds were obtained in high purity as judged by thin-layer chromatography, high-performance liquid chromatography, 1H NMR and mass spectral data, and elemental analysis results.


Elemental Analysis Result Benzyl Ester Methyl Grouping Catalytic Hydrogenolysis Peptide Coupling 
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  1. 1.
    (a) C. M. Baugh, C. L. Krumdieck, and M. G. Nair, Biochem. Biophys. Res. Commun., 52, 27 (1973);PubMedCrossRefGoogle Scholar
  2. 1.
    (b) C. M. Baugh and M. G. Nair, Biochemistry, 12, 3923 (1973).PubMedCrossRefGoogle Scholar
  3. 2.
    V. M. Whitehead, M. M. Perrault, and S. Stelcner, Cancer Res., 35, 2985 (1975).PubMedGoogle Scholar
  4. 3.
    V. M. Whitehead, Cancer Res., 37, 408 (1977).PubMedGoogle Scholar
  5. 4.
    S. A. Jacobs, C. J. Derr, and D. G. Johns, Biochem. Pharmacol., 26, 2310 (1977).PubMedCrossRefGoogle Scholar
  6. 5.
    D. S. Rosenblatt, V. M. Whitehead, M. M. Dupont, M. J. Vuchich, and N. Vera, Molec. Pharmacol., 14, 210 (1978).Google Scholar
  7. 6.
    R. L. Schilsky, B. D. Bailey, and B. A. Chabner, Proc. Natl. Acad. Sci. USA, 77, 919 (1980).CrossRefGoogle Scholar
  8. 7.
    A. Witte, M. Whitehead, D. S. Rosenblatt, and M. S. Vuchich, Dev. Pharmacol. Ther., 1, 40 (1980).PubMedGoogle Scholar
  9. 8.
    D. S. Rosenblatt, V. M. Whitehead, N. Vera, A. Pottier, M. Dupont, and M.-J. Vuchich, Molec. Pharmacol., 14, 1143 (1978).Google Scholar
  10. 9.
    J. Galivan, Molec. Pharmacol., 17, 105 (1980).Google Scholar
  11. 10.
    S. A. Jacobs, R. H. Adamson, B. A. Chabner, C. J. Derr, and D. G. Johns, Biochem. Biophys. Res. Commun., 63, 692 (1975).PubMedCrossRefGoogle Scholar
  12. 11.
    F. M. Sirotnak, P. L. Chello, J. R. Piper, and J. A. Montgomery, Biochem. Pharmacol., 27, 1821 (1978).PubMedCrossRefGoogle Scholar
  13. 12.
    D. W. Szeto, Y.-C. Cheng, A. Rosowsky, C.-S. Yu, E. J. Modest, J. R. Piper, C. Temple Jr., R. D. Elliott, J. D. Rose, and J. A. Montgomery, Biochem. Pharmacol., 28, 2633 (1979).PubMedCrossRefGoogle Scholar
  14. 13.
    J. R. Piper and J. A. Montgomery, J. Org. Chem., 42, 208 (1977).PubMedCrossRefGoogle Scholar
  15. 14.
    J. R. Piper and J. A. Montgomery, in: “Chemistry and Biology of Pteridines,” R. L. Kisliuk and G. M. Brown, eds., Elsevier/ North-Holland (1979), pp. 261–265.Google Scholar
  16. 15.
    T. Shioiri, K. Ninomiya, and S. Yamada, J. Am. Chem. Soc, 94, 6203 (1972).PubMedCrossRefGoogle Scholar
  17. 16.
    A. K. Bose and R. E. Strube, J. Pharm. Sci., 52, 847 (1963).PubMedCrossRefGoogle Scholar
  18. 17.
    Purchased from Chemical Dynamics Corporation, South Plainfield, New Jersey.Google Scholar
  19. 18.
    (a) J. Meienhofer, P. M. Jacobs, H. A. Godwin, and I. H. Rosenberg, J. Org. Chem., 35, 4137 (1970);PubMedCrossRefGoogle Scholar
  20. 18.
    (b) H. A. Godwin, I. H. Rosenberg, C. R. Ferenz, P. M. Jacobs, and J. Meienhofer, J. Biol. Chem., 247, 2266 (1972).PubMedGoogle Scholar
  21. 19.
    C. N. C. Drey and G. P. Priestly, J. Chem. Research (M), 3055 (1979).Google Scholar
  22. 20.
    M. C. Kirk, W. C. Coburn Jr., and J. R. Piper, Biomed. Mass Spectrom., 3, 245 (1976).PubMedCrossRefGoogle Scholar
  23. 21.
    Intermediate 6 was first prepared using i-butyl chloroformate as the coupling agent [14]. We have since prepared 6 using diphenylphosphoryl azide and found the two procedures to be about equally effective.Google Scholar

Copyright information

© Springer Science+Business Media New York 1983

Authors and Affiliations

  • James R. Piper
    • 1
  • John A. Montgomery
    • 1
  1. 1.Organic Chemistry Research Department, Kettering-Meyer LaboratorySouthern Research InstituteBirminghamUSA

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