Novel monoterpene lactones from Cinnamomum inunctum

Four new monoterpene lactones, 5-(2,3-dihydroxy-3-methylbutyl)-4-hydroxy-4-methyldihydrofuran-2(3H)-one (1), 5-(2,3-dihydroxy-3-methylbutyl)-4-methylfuran-2(5H)-one (2), 8-hydroxy-4,7,7-trimethyl-1,6-dioxaspiro[4.4]non-3-en-2-one (3) and 8-hydroxy-4,7,7-trimethyl-1,6-dioxaspiro[4.4]non-3-en-2-one (4), were isolated from the methanolic extract of the fruit of Cinnamomum inunctum, a folk medicine in Myanmar, together with a known compound, 3-hydroxy-4,4-dimethyl-4-butyrolactone (5). Their chemical structures were determined by spectral methods. Among these, 3 and 4 possessed unique spirolactone moieties.