We derive the effective chiral Lagrangian for low-energy eta-nucleon and et
a'-nucleon interactions and show that gluonic degrees of freedom, via the a
xial U-A(1) anomaly, induce a contact term in the pp --> pp eta and pp -->
pp eta' reactions. We then discuss the consequences for the extraction of g
(eta'NN) from experimental data. (C) 1999 Elsevier Science B.V. All rights
reserved.