THE PRESENT INVENTION DISCLOSES A NATURAL COMPOSITION FOR USE IN INHIBITING CORROSION OF A METALLIC-BASED SUBSTANCE. SAID NATURAL CORROSION INHIBITING COMPOSITION COMPRISES QUERCETIN (10) EXTRACTED FROM AILIUM CEPA.PREFERABLY, THE QUERCETIN EXTRACTED FROM ALLIUM CEPA, PARTICULARLY THE OUTERMOST SKINS OF ALLIUM CEPA, INCLUDING 3,4’O—QUERCETIN DIGLUCOSIDE (3,4’- QDG) AND 4’O-QUERCETIN QLUCOSIDE (4’QMG).