Asparagusic acid

Asparagusic acid, S2(CH2)2CHCO2H is an organosulfur carboxylic acid present in the vegetable asparagus and may be the metabolic precursor to other odorous thiol compounds. Biosynthetic studies revealed that asparagusic acid is derived from the amino acid valine. This colorless solid has a m.p. of 75.7-76.5 °C. The corresponding dithiol (m.p. 59.5-60.5 °C) is also known; it is called dihydroasparagusic acid or dimercaptoisobutyric acid.

Isolation
From 40 kg of "asparagus aroma concentrate," Jansen obtained 32 g of a compound he identified as 3,3’-dimercaptoisobutyric acid.

see thiol