Neoclerodane Diterpenoids from Scutellaria pontica

Seven novel neoclerodane diterpenoids, scupontins A-G, have been isolated from the Me2CO extract of the aerial parts of Scutellaria pontica (1-7), together with the known neoclerodanes scutalbin A and scutalpin M. Structures 1-7 were established by exhaustive NMR spectroscopic studies and chemical transformations. Scupontins A-D(1-4, respectively) and scupontins E (5)andF(6) possess unusual [(3¢S,3¢¢S)-3¢-[(3¢¢-acetoxybutyryl)oxy]butyryloxy and [(3¢S,3¢¢S,3¢¢¢S)- 3¢-[[3¢¢-[(3¢¢¢-hydroxybutyryl)oxy]butyryl]oxy]butyryl]oxy substituents, respectively, attached to the C-19 position of the neoclerodane framework. In the case of the 6R,7â-dibenzoate derivative 7 (scupontin G) its absolute config…