Characteristics of Effective and Host Specific Ineffective Strains of Rhizobium japonicum

The formation of dimers in the initial stage of methyl linoleate (ML) autoxidation was demonstrated. The oxidation profile of freshly prepared ML was followed by TLC during autoxidation by aeration at 30°C for 192 hr. After 24 hr of autoxidation, the peroxide value of ML was still 0.6, and two unknown polar spots appeared besides intact ML and methyl linoleate hydroperoxides (MLHPO). These two spots were identified as dimers by successive gel and high performance liquid Chromatographic separations and by molecular weight determination. The ratio of dimers/MLHPO reached a maximum (0.74) after 96 hr of autoxidation. This result indicates that the formation of dimers in the initial stage of autoxidation was slightly less than that of MLHPO. The dimers were linked through ?C?O?O?C? bonds and contained hydroperoxy and/or carbonyl groups and conjugated dienes.