Quantitative determination of naphthoquinones of Impatiens species

A convenient and reliable reversed phase-HPLC method has been developed and validated for the quantitative determination of naphthoquinones present in the aerial parts of Impatiens glandulifera (Balsaminaceae) during two grow ing seasons (May to August 1998 and June to October 1999). Maximal content (0.8-1.1%) of 2-hydroxy-1,4-naphthoquinone and its 2-methylated derivative was observed in flowers collected between July and August. The procedure wa s applied to compare the pigment content in three other species of Impatien s but showed 2.5-37 times lower levels than those found in I. glandulifera. Copyright (C) 2001 John Wiley & Sons, Ltd.