Lanosterol

Lanosterol is a tetracyclic triterpenoid and is the compound from which all animal and fungal steroids are derived.

[1] In the eyes of vertebrates, lanosterol is a natural constituent, having a role in maintaining health of the lens.

[2] Elaboration of lanosterol under enzyme catalysis leads to other steroids.

[3][4] Its proposed mechanism of action is to inhibit the aggregation of crystallin proteins, which contribute to the clouding of vision by forming cataracts.

[3][4] Lanosterol is under research for its potential as a therapeutic additive in eye drops to inhibit the aggregation of crystallin proteins and dissolve cataracts.

Ball-and-stick model of lanosterol
Simplified version of the lanosterol synthesis pathway with the intermediates isopentenyl pyrophosphate (IPP), dimethylallyl pyrophosphate (DMAPP), geranyl pyrophosphate (GPP), and squalene shown. Some intermediates are omitted.