Stereochemical Aspects of Transmethylations of Potential Biological Interest

Abstract

In 1954, Shive and co-workers demonstrated the occurrence of S-methylmethionine $\left( {\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle\thicksim}$}}\to {1} } \right)$ (MMT) in cabbage and several other vegetables.¹ Subsequently, $\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle\thicksim}$}}\to {1}$ has been reported as a constituent of asparagus, ^{2, 3} jack beans, ⁴ pelargonium and mint leaves, ⁵ green tea, ^{3, 6} soybean meal, ⁷ celery, ³ tomatoes, ^{3, 8} sweet corn, ⁹ potatoes, ¹⁰ apples, ¹¹ and milk. ¹² The amazingly wide distribution of $\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle\thicksim}$}}\to {1}$ justifies inquiries into its chemistry, biosynthesis, metabolism, and biological significance.