A new tetracyclic saponin from L. and its neuroprotective and hMAO-B inhibiting activity.

A new tetracyclic saponin, 17(),20()-3,6,16-trihydroxycycloartanyl-23-carboxylic acid 16-lactone 3-O--D-glucopyranoside () together with one known flavonoid, camelliaside A () were isolated from the aerial parts of L. Their structures were determined by chemical, HRESIMS and NMR methods. On 6-hydroxydopamine model on isolated rat brain synaptosomes, compounds - had statistically significant neuroprotective activity similar to that of Silibinin, tested at 100 μM. Saponin possessed the most prominent neuroprotective and antioxidant effects in this model. On human recombinant monoamine oxidase type B enzyme compound displayed strong inhibiting activity, compared to Selegiline (1 μM). It could be concluded that the new epoxycycloartane saponin could be a promising leading structure in respect of neurodegenerative diseases.