Dibothrioclinin I and II, epimers from Gerbera piloselloides (L.) Cass
Yang Lu, e-mail: [email protected]
Abstract
Dibothrioclinin I and II, namely (+)-(11R,12S,25R,27S)- and (±)-(11RS,12RS,25RS,27SR)-3,3,7,17,21-pentamethyl-4,12,18,26-tetraoxaheptacyclo[15.11.1.02,15.05,14.06,11.019,28.020,25]nonacosa-5(14),6,8,10,19(28),20,22,24-octaene-13,27-dione, respectively, are C30H28O6 epimers which are derived from two bothrioclinin moieties joined so as to create an additional six-membered ring. Structurally, the epimers differ only by inversion at one C atom of a central ring junction and the corresponding six-membered rings have similar conformations in each molecule, except for one ring adjacent to this inversion site.
