(Effects of Environmental Stress on an Indigenous Medicinal Plant (Pergularia tomentosa L

Abstract

In this study some cardiac glycoside were isolated from mature Pergularia tomentosa growing in the Egyptian desert and compared with plants growing in controlled laboratory conditions. Particular attention in this study was given to the strategies of cardiac glycoside compounds present in the root and shoot of Pergularia tomentosa under different watering regimes.

Nine cardiac glycoside compounds, namely: 1, 2, 3, 4, 5, 6, and unknown compounds, 1, 2 and 3 were isolated and their structures determined on the basis of 1D CHNMR, 13CNMR, TOCSY) and 2D(HSQC, HMBC) NMR and ESI mass spectra. Three of these compounds were detected as new glycosides, and another three were first isolated from this plant.

The effects of water stress (10%, 20%, 40%, 60%, 80% and

100% of field capacity) on the growth of Pergularia tomentosa, the HPLC profiles of the isolated compounds and total cardiac glycosides were studied. In addition, the role of these compounds in drought tolerance was interpreted.