Naphthalene Aglycones and Glycosides from the Australian Medicinal Plant, Dianella callicarpa

The crude extract of the roots from the Australian medicinal plant Dianella callicarpa (Liliaceae) displayed significant antimicrobial and antiviral activities. This prompted a chemical investigation, resulting in the isolation of the new naphthalene glycoside, dianellose (10), together with dianellin (1), dianellidin (2), dianellinone (3), stellalderol (9) and 5-hydroxydianellin (11). The structures for compounds 1, 9 and 10 were secured by detailed spectroscopic analyses, while compounds 2, 3 and 11 were identified on the basis of comparisons to literature data. Whilst the chemistry of the genus Dianella has previously been investigated, we report the first isolation of stellalderol (9) from this genus, together with the chemical and biological evaluation of the callicarpa species. Biological evaluation of the isolated compounds established that 2 showed antiviral and mild antimicrobial properties and that compounds 1, 9 and 10 displayed moderate antitumour activities.