Phytochemical profile of aerial parts and roots of Wachendorfia thyrsiflora L. studied by LC-DAD-SPE-NMR

Abstract

Hyphenated liquid chromatography – diode array detection – solid phase extraction – nuclear magnetic resonance spectroscopy (LC-DAD-SPE-NMR) was used to investigate the phytochemical composition of aerial parts and roots of Wachendorfia thyrsiflora (Haemodoraceae). Eleven phenylphenalenones and related compounds were identified in the aerial parts of the plant, ten compounds were found in the roots, and four additional compounds occurred in both plant parts. Twelve compounds are previously unreported natural products including five alkaloids (phenylbenzoisoquinolinones) are described here for the first time. In the work presented here, phenylphenalenones with an intact C19 core structure were found only in the roots. Oxa analogs with a C18O scaffold occurred both in the roots and in the aerial plant parts, while most of the aza analogs with a C18N scaffold were detected in the aerial plant parts. This distribution pattern suggests that phenylphenalenones form in the roots, then the intact C19 skeleton is converted into oxa analogs in the roots, translocated into the leaves and further reacted with amines or amino acids to form aza analogs (phenylbenzoisoquinolin-1,6-dione alkaloids).