Bilobalide is a main constituent of the terpenoids found in the leaves of Ginkgo biloba, a tree whose leaves are used in herbal medicine. Its exact synthesis pathway from farnesyl pyrophosphate is still unknown. Source: Wikipedia
It has been widely used for many years as a 'herbal remedy' in treatment of strokes and other disorders.
Evidence which has accumulated during the last few years indicates that bilobalide may have neuroprotective effects. Further studies seem warranted to determine its possible usefulness in developing therapy for disorders involving cerebral ischemia and neurodegeneration.
Source: Pharmacological Research Volume 46, Issue 6, Pages 565-568
Its mecahnism of action is currently unknown.