Comparison of Bioactive Secondary Metabolites in Experimental and Natural Populations of Wild Tomatillos, Physalis longifolia Nutt.

Abstract

We conducted a field experiment to determine the effects of mulch, fertilizer, and mycelium on biomass and important secondary metabolite concentrations in the edible and medicinal plant Physalis longifolia Nutt., with the hypothesis that increased plant stress (i.e., no mulch, fertilizer, or mycelium) would decrease biomass production and increase secondary compound content. Experimental cultivated plots and natural populations of P. longifolia were evaluated for the abundance of major bioactive withanolides previously isolated from the species: withalongolide A (1), withaferin A (2), and withalongolide B (3). Results indicated negligible differences between experimental treatments in biomass yield and withanolide abundance. However, withanolide concentrations from wild populations varied considerably with some being much higher than the source population used in the experiment. These results suggest that variation in secondary compound concentrations among wild populations is an important consideration when selecting source material for the cultivation of medicinal plants.