INHIBITION OF LIPID-PEROXIDATION BY DITERPENOID FROM PODOCARPUS-NAGI

A diterpenoid, totarol (1), from Podocarpus nagi was evaluated as an a ntioxidant. This diterpenoid inhibited autoxidation of linoleic acid. Mitochondrial and microsomal lipid peroxidation induced by Fe(III)-ADP /NADH or Fe(III)-ADP/NADPH were also inhibited. Nagilactone E (2), a n orditerpene lactone isolated from the same source, had no antioxidativ e activity. Furthermore, totarol protected red cells against oxidative hemolysis. This diterpene was shown to be effective in protecting bio logical systems against oxidative stresses.