Lupeol

Lupeol is a pharmacologically active pentacyclic triterpenoid. It has several potential medicinal properties, like anticancer and anti-inflammatory activity.

Natural occurrences
Lupeol is found in a variety of plants, including mango, Acacia visco and Abronia villosa. It is also found in dandelion coffee. Lupeol is present as a major component in Camellia japonica leaf.

Total synthesis
The first total synthesis of lupeol was reported by Gilbert Stork et al.

In 2009, Surendra and Corey reported a more efficient and enantioselective total synthesis of lupeol, starting from (1E,5E)-8-[(2S)-3,3-dimethyloxiran-2-yl]-2,6-dimethylocta-1,5-dienyl acetate by use of a polycyclization.

Biosynthesis
Lupeol is produced by several organisms from squalene epoxide. Dammarane and baccharane skeletons are formed as intermediates. The reactions are catalyzed by the enzyme lupeol synthase. A recent study on the metabolomics of Camellia japonica leaf revealed that lupeol is produced from squalene epoxide where squalene play the role as a precursor.

Pharmacology
Lupeol has a complex pharmacology, displaying antiprotozoal, antimicrobial, antiinflammatory, antitumor and chemopreventive properties.

Animal models suggest lupeol may act as an anti-inflammatory agent. A 1998 study found lupeol to decrease paw swelling in rats by 39%, compared to 35% for the standardized control compound indomethacin.

One study has also found some activity as a dipeptidyl peptidase-4 inhibitor and prolyl oligopeptidase inhibitor at high concentrations (in the millimolar range).

It is an effective inhibitor in laboratory models of prostate and skin cancers.

As an anti-inflammatory agent, lupeol functions primarily on the interleukin system. Lupeol to decreases interleukin 4 (IL-4) production by T-helper type 2 cells.

Lupeol has been found to have a contraceptive effect due to its inhibiting effect on the calcium channel of sperm (CatSper).

Lupeol has also been shown to exert anti-angiogenic and anti-cancer effects via the downregulation of TNF-alpha and VEGFR-2.

The leaves of Camellia japonica contain lupeol.