Chromenone Glucosides Acylated with Monoterpene Acids from the Leaves of Eucalyptus camaldulensis var. obtusa

Three new chromenone glucosides acylated with monoterpene acids, eucamaldusides A (1), B (2), and C (3), were isolated from the leaves of Eucalyptus camaldulensis var. obtusa, together with the five known compounds ursolic acid lactone, obtusilin, beta-sitosterol glucoside, 4-hydroxybenzoic acid, and cypellocarpin C. The structures of the new compounds were established by exhaustive 1D- and 2D-NMR spectroscopic studies. Their configuration was determined by measuring the [alpha](D) of the known methyl esters of the monoterpene acids obtained by methanolysis of 1-3.