Rosmarinic acid


Rosmarinic acid is a chemical compound found in a variety of plants.

History

Rosmarinic acid was first isolated and characterized in 1958 by the Italian chemists M. L. Scarpatti and G. Oriente from rosemary.

Chemistry

Chemically, rosmarinic acid is a caffeic acid ester of 3-lactic acid.

Natural occurrences

Rosmarinic acid accumulation is shown in hornworts, in the fern family Blechnaceae and in species of several orders of mono- and dicotyledonous angiosperms.
It is found most notably in many Lamiaceae, especially in the subfamily Nepetoideae. It is found in species used commonly as culinary herbs such as Ocimum basilicum, Ocimum tenuiflorum, Melissa officinalis, Rosmarinus officinalis, Origanum majorana, Salvia officinalis, thyme and peppermint. It is also found in plants in the family Marantaceae such as species in the genera Maranta and Thalia.
Rosmarinic acid and the derivative rosmarinic acid 3′-O-β-D-glucoside can be found in Anthoceros agrestis, a hornwort.

Biosynthesis

The biosyntheses of rosmarinic acid uses 4-coumaroyl-CoA from the general phenylpropanoid pathway as hydroxycinnamoyl donor. The hydroxycinnamoyl acceptor substrate comes from the shikimate pathway: shikimic acid, quinic acid and 3,4-dihydroxyphenyllactic acid derived from L-tyrosine. Thus, chemically, rosmarinic acid is an ester of caffeic acid with 3,4-dihydroxyphenyllactic acid, but biologically, it is formed from 4-coumaroyl-4'-hydroxyphenyllactate. Rosmarinate synthase is an enzyme that uses caffeoyl-CoA and 3,4-dihydroxyphenyllactic acid to produce CoA and rosmarinate. Hydroxyphenylpyruvate reductase is also an enzyme involved in this biosynthesis.