C-27 Apocarotenoids in the flowers of Boronia megastigma (Nees)

Five C-27 apocarotenoids were detected in acetone extracts of the flowers of Boronia megastigma (Nees) using HPLC with UV-vis photodiode array and MS detection. Comparison of methylated and unmethylated extracts aided identification when considered with the UV-vis and MS data. The five apocarotenoids identified here were hydroxy-apo-10′-carotenoic acid (1), methyl hydroxy-apo-10′-carotenoate (2), apo-10′-carotenoic acid (3), apo-10′-carotenal (4), and methyl apo-10′-carotenoate (5). The data obtained was not sufficient to allow the specific isomeric forms to be unequivocally identified. The results further support speculation that the C-13 norisoprenoids found in boronia are derived from C-40 carotenoids. Possible parent molecules of β-ionone, an important component of boronia extract, were identified. An understanding of C-13 norisoprenoid biosynthesis may assist in the selection and postharvest processing of boronia flowers for flavor and fragrance applications.