We present an exploratory investigation of the parity odd
$\Delta I = 1$ pion-nucleon coupling $h_\pi^1$ from lattice
QCD. Based on the PCAC relation, we study the parity-conserving
effective Hamiltonian and extract the coupling by determining the
nucleon mass splitting arising from the effective 4-quark
interactions using the Feynman-Hellmann theorem.
We present preliminary results of the mass shift for a $32^3 \times
64$ ensemble of $N_f = 2 + 1 + 1$ twisted mass fermions at pion
mass $260$ MeV and lattice spacing $a = 0.097$ fm.
