Pentacyclic triterpenoid esters

Further work on the free and ester-bound triterpenoid alcohols in cellular subtractions of Calendula officinalis flowers has appeared. An investigation of the mass spectral fragmentation of pentacyclic hydrocarbons in petroleum has been published. ... 

In C.halimii leaf wax triterpenoids were found in the very high amount of 72%,beside the wax lipids. The free triterpenols dominated with about 62%. Identified could be B-amyrin, a-amyrin and lupeol. In small amounts esters of B-amyrin and a-amyrin containing long chain fatty acids were found. Again triterpene ketones were isolated and detected with the aid of GC/MS. In this wax lupenone was present and also one other ketone named fridelanone in the remarkable amount of about 12%. They could be reduced to the corresponding alcohols. Fridelanone and fride-lanol have a pentacyclic structure without any double bond. Therefore these substances showed quite different Rf values in TLC and no colour reaction with carbazole (3)(Fig.l). 

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