Triterpenoids from Abies species X. Two new 3,4-secotriterpene acids from the oleoresin of the silver fir

Two new 3,4-secotriterpene acids have been isolated in the form of dimethyl esters from the acid fraction of the oleoresin of the silver firAbies alba Mill. On the basis of spectral characteristics and the results of a chemical correlation with the known triterpenoids methyl abiesolidate, dimethyl abiesonate and methyl firmanoate it has been established that they are (25R)-3,4-seco-9β-lanosta-4(28),7-dien-23-one-3,26-dioic acid and (25R)-3,4-seco-abiesa-4(28),7,14(30)-trien-23-one-3,26-dioic acid. Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, Novosibirsk. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 765–770, November–December, 1990.