In this work we demonstrate the successful optimization of the interfacial polymerization reaction for the manufacture of organic solvent nanofiltration membranes by replacing the toxic amines commonly used for this method with the natural occurring bio-polyphenol morin. For the manufacture of this type of OSN membrane a crosslinked PAN support was coated by interfacial polymerization using morin as the monomer of the aqueous phase and terephthaloyl chloride as the monomer of the organic phase. These membranes showed an exceptional performance and resistance to NMP by having a permeance of 0.3 L/m(2) h bar in NMP with a rejection of 96% of Brilliant Blue dye which has a molecular weight of 825.97 g/mol, making these membranes attractive for harsh industrial separation processes due to their ease of manufacture, low cost, and excellent performance.