The use of natural gel is generating interest of researchers toward cost effective, nontoxic, economic viability and eco-friendly green synthesis of nanoparticles. In the present work, Ni0.35Cu0.25Mg0.4Fe2O4 MNPs were synthesized using tragacanth gum as biotemplate and Metals nitrate as the metal source by the sol–gel method without using any organic chemicals. The sample was characterized by powder X-ray diffraction, fourier transform infrared spectroscopy, vibrating sample magnetometer and scanning electron microscopy. The X-ray powder diffraction analysis revealed the formation of Cubic phase ferrite MNPs with average particle size of 19 nm. Thereupon, Ni–Cu–Mg ferrite nanoparticles as an efficient catalyst was used for the synthesis of polyhydroquinoline derivatives via multi-component reactions under microwave irradiation. Simple work-up, mild reaction conditions, short reaction times, use of an economically convenient catalyst, and excellent product yields (82–98%) are the advantageous features of this method. The catalyst could easily be recycled and reused six times without noticeable decrease in catalytic activity.
