Diterpene constituents of leaves from Juniperus brevifolia.

The dichloromethane extract from leaves of Juniperus brevifolia, through chromatographic fractionations yield six compounds: 3beta-hydroxy-abieta-8,11,13-trien-7-one, 18-hydroxy-sandaracopimara-8(14),15-dien-7-one, sandaracopimara-8(14),15-dien-18-yl formate; and the first examples of sandaracopimaranes and abieta-8,11,13-triene diterpenoids with a large aliphatic chain on C-18, abieta-8,11,13-trien-18-yl hexadecanoate, 7-oxoabieta-8,11,13-trien-18-yl hexadecanoate, sandaracopimara-8(14),15-dien-18-yl hexadecanoate. Moreover fifteen known compounds were also isolated, some of them for the first time identified on Juniperus genus. The compound abieta-8,11,13-trien-18-yl formate is reported for the first time as a natural product. All the structures were established by spectroscopic methods. 2D NMR techniques have allowed the revision of certain previously reported (13)C NMR assignments. Studies on the isolated new compounds showed those possessing a diterpenol ester of a long-chain fatty acid present lipophilicity very distinct from other diterpenoid compounds.