Gastroprotective activity of the diterpene solidagenone and its derivatives on experimentally induced gastric lesions in mice.

The labdane diterpene solidagenone 1 and its semisynthetic and biotransformations products 2-7 were assessed for gastroprotective effect in the HCl.EtOH-induced lesions in mice. At 100 mg/kg, solidagenone presented a statistically significant gastroprotective effect (P<0.05) comparable to lansoprazole at 20 mg/kg. The presence of the furan ring was required for the activity of solidagenone while hydroxylation at C-3 or C-6 afforded products with different activity associated with the stereochemistry. Solidagen-6beta-ol 7 and 3alpha-hydroxysolidagenone 2 presented higher activity than solidagenone itself, while its epimers were inactive.