Structural analogs of bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propyl] sulfide (the SO-3 stabilizer), symmetrical and unsymmetrical sulfides with a varying number of tert-buty] ortho-substituents in the phenol moiety, were synthesized. The antioxidant power of these compounds was compared for two auto-oxidation substrates, lard and petrolatum oil.