- Synthesis and characterization of a series of diarylguanidines that are noncompetitive N-methyl-D-aspartate receptor antagonists with neuroprotective properties. Keana, J.F., McBurney, R.N., Scherz, M.W., Fischer, J.B., Hamilton, P.N., Smith, S.M., Server, A.C., Finkbeiner, S., Stevens, C.F., Jahr, C. Proc. Natl. Acad. Sci. U.S.A. (1989)