Biological activity of hydroxo-vitamin B-12 degradation product formed during microwave heating

摘要

When hydroxo-vitamin B-12, which predominates in foods, is treated by microwave heating, two degradation products with R-f of 0.16 and 0.27 are found and characterized (Watanabe et al. J. Agric. Food Chem. 1998, 46, 206-210). A novel hydroxo-vitamin Bit degradation product with a R-f of 0.12 was also found by the use of silica gel 60 column chromatography and was the major compound among the degradation products. The degradation product with a R-f of 0.12 was purified to homogeneity and partially characterized. The purified degradation product had about 13% and 23% biological activity of authentic vitamin B-12 in hog intrinsic factor (a mammalian vitamin Bra-binding protein) and Lactobacillus Leichmannii ATCC 7830, respectively. Administration of the purified degradation product (0.5 mu g/week) to rats indicates that the compound does not have significant activity in mammals. [References: 11]