Phenylanthraquinones and flavone-C-glucosides from the disjunct Bulbinella in New Zealand

Abstract The genera Bulbine , Bulbinella and Kniphofia produce phenylanthraquinones and are mostly found in southern Africa, although a disjunct group of Bulbinella species endemic to New Zealand also contain phenylanthraquinones as reported herein. The sub-Antarctic megaherb B . rossii yielded sulphated phenylanthraquinones, including a phenylanthraquinone found to carry a sulphated glycoside substituent, 4′- O -demethylknipholone-4′-β-D-xylopyranosyl-3″-sulphate. A sensitive HPLC method was used to analyse 5 of the 6 New Zealand Bulbinella species, all of which contained phenylanthraquinones. Leaves and roots had different profiles, but species were not distinct. Roots were rich in sulphated and free phenylanthraquinones (0.27 ± 0.09% dry wt), whereas leaves typically only contained free knipholone (0.14 ± 0.01%). Localisation of phenylanthraquinones to the stele and peel was observed in roots. Two flavone-C-glucosides were found in leaves of Bulbinella .