New caryophyllene derivatives from Betula litwinowii.

Four new caryophyllene derivatives-14-hydroxy-4, 5-dihydro-beta-caryophyllene (1), 14-acetoxy-4, 5-dihydro-beta-caryophyllene (2), 4, 5-dihydro-beta-caryophyllene-14-al (3), and caryophylla-8(14)-en-5-one (4)-are reported from the essential oil of Betula litwinowii. Compounds 1-4 were characterized by MS and 1D and 2D NMR analyses and chemical transformations. The antibacterial and antifungal activity of 1 is also reported.