The interactions of pseudoscalar mesons with hyperons can be described by
L=gπ+pnπ+pˉiγ5n+gK+pΛK+pˉiγ5Λ+gK+nΣ−K+nˉiγ5Σ−+⋯+h.c.,(3.194)
where the dots refer to other mesons and hyperons. Show that gK+nΣ− can be expressed in terms of gπ+pn and gK+pΛ in the SU(3) limit, and find the expression.