A Chemotaxonomic Study of the New Zealand Araliaceae

Abstract

The New Zealand members of the Araliaceae (16 species, 4 varieties of Pseudopanax, 1 species of Meryta and 1 species of Schefflera, all endemic to New Zealand) are examined for their phenolic constituents. It appears that the flavonoid profiles for this group are based, primarily, on the flavonols quercetin and kaempferol. The flavones luteolin and apigenin are also present. Ultra-violet Absorption spectroscopy confirms the presence of these compounds which occur as 3-O monoglycosides or 3-O diglycosides in the case of the flavonols and 6-8 di-C or 8-C monoglycosides in the case of the flavones. The distribution of these compounds supports the groupings first proposed by Philipson in 1971 with one exception. Pseudopanax edgerleyi produces a pattern unlike the other members of the group Philipson assigned it to. The results of differences between adult and juvenile are not as clear as expected and can not be used with any degree of certainty to distinguish the different forms. The three varieties of Pseudopanax colensoi can, however, be distinguished on the basis of their flavonoid patterns. Altitude and geographical location are shown to have little effect upon the chromatographic pattern of the flavonoid compounds produced. The presence of flavonols and flavones indicate the New Zealand members of the Araliaceae are of intermediate advancement on the evolutionary scale of flavonoid compounds as proposed by Harborne in 1972. They also throw doubt upon the suggestion by Harborne that flavones are absent from the Araliaceae. The proposal made by Hutchinson in 1969 that the Araliaceae are from different ancestral stock to the Umbelliferae and are products of convergent evolution is discussed but not completely substantiated by this study.