3-methylthiopropionate is one of the metabolites of methionine (especially of D-methionine). Cultures of Streptomyces lincolnensis accumulated 3-methylthioacrylic acid in amounts directly related to the concentration of methionine in the medium. The first intermediate in the pathway may be the keto acid which is then oxidatively decarboxylated to 3-methylthiopropionic acid.

Methyl 4-prenyloxycinnamate is a Phenylpropanoids product that can be isolated from the barks of Cinnamomum cassia.

Aristolochic acid B is one of the major components of the carcinogenic plant extract aristolochic acid, is known to be mutagenic and to form DNA adducts in vitro and in vivo.