S-Methylmethionine

S-Methylmethionine (also known as Vitamin U) is a derivative of methionine which is found in various plant species. It was first isolated in 1949 by Garnett and co-workers from cabbage juice, where it was shown to have a protective effect on peptic ulcers in humans.

Chemistry

S-Methylmethionine is a quaternary ammonium salt that is structurally similar to the amino acid methionine, except that the alpha-hydrogen is replaced by a methyl group. It is synthesized in plants from methionine and S-adenosyl methionine (SAM) via the Yang cycle.

Biological role

In plants, S-Methylmethionine acts as a methyl donor in a variety of methylation reactions. It is also involved in the synthesis of ethylene, a plant hormone that regulates growth and development.

In humans, S-Methylmethionine has been shown to have a protective effect on the gastrointestinal tract, particularly in the prevention and treatment of peptic ulcers. However, its exact mechanism of action is still not fully understood.

Sources

S-Methylmethionine is found in a variety of plant species, including cabbage, spinach, and alfalfa. It is also available as a dietary supplement.

Safety

S-Methylmethionine is generally considered safe when consumed in amounts typically found in food. However, excessive intake may cause mild gastrointestinal symptoms such as nausea and diarrhea.

See also

• Methionine
• S-adenosyl methionine
• Peptic ulcer