The identification of natural compounds: methoxylated phenolics from Vitex and Pandanus species

摘要

Plants produce various types of natural compounds, including polyphenols. These compounds are also found with methoxyl groups attached to the oxygenated carbon atoms. Nevertheless, the occurrence of methoxylated phenolics in two unrelated plants, Vitex and Pandanus species, could be considered unusual. From the literature review, most of the published phytochemicals from both plants include triterpenes and alkaloids. In this study, silica gel chromatographic separation of their leaves extracts yielded a quercetin pentamethyl ether I and a novel lignan, [4,8-bis(2,4-dimethoxyphenyl)-3,7-dioxabicyclo[3.3.0]octane, 2, from Vitex trifolia (family: Lamiaceae) and Pandanus pygmaues (family: Pandanaceae), respectively. The identification of both compounds is described from the results of the spectroscopic experiments. The chemosystematic analysis of these plants are however, would not be initiated by the discovery of these minor constituents. The Vitex's terpenoids and pandan alkaloids, which are the principal metabolites of these plants, are in the anticipation of chemistry learning from nature.