Labdane is a natural bicyclic diterpene. It forms the structural core for a wide variety of natural products collectively known as labdanes or labdane diterpenes. The labdanes were so named because the first members of the class were originally obtained from labdanum, a resin derived from the gum rockrose.

A variety of biological activities have been determined for labdane diterpenes including antibacterial, antifungal, antiprotozoal, and anti-inflammatory activities. Natural labdanes in tree resin are believed to be the precursors of amber, which polymerise under great pressure.

Biosynthesis

The enzyme (13E)-labda-7,13-dien-15-ol synthase produces the labdane, (13E)-labda-7,13-dien-15-ol, directly from geranylgeranyl pyrophosphate in the lycophyte Selaginella moellendorffii. The reaction proceeds in two steps: cyclisation and then hydrolysis, with pyrophosphate (PPi) as a byproduct.

Example labdane derivatives

• Forskolin

• Galanolactone

• Isocupressic acid - is an abortifacient component of Cupressus macrocarpa.

• Medigenin

• Sclareol

• Stemodene

See also

• Abietane

References