Interband magneto-photoluminescence from asymmetric modulation-doped GaAs-GaAlAs quantum wells has been investigated. In addition to the free-carrier Landau level excitations, transitions between magneto-donor and free hole states have been observed. Experiments with tilted magnetic field provide strong evidence for the existence of conduction electrons bound to ionized magneto-acceptors characterized by discrete energies above the conduction band Landau levels.