Preliminary chemical studies of aquatic plants from Minnesota

Twenty-two aquatic plants were collected from various Minnesota lakes and studied for the presence of alkaloids, flavonoids, steroids, and lipids. Alkaloids are present in Nymphaea tuberosa and Nuphar variegatum. Flavonols and flavonones were often present in the plants studied whereas anthocyanidins and aurones were not. Beta-sitosterol was present in eight, and saponin in five of the plants studied. Cardenolides, as well as 3- and 17-oxo-steroids, were absent from the plants surveyed. Potamogeton natans, Sagittaria latifolia and N. tuberosa contained relatively higher total lipid contents (5.35, 5.24 and 3.91 weight % of dried plant material, respectively) than the other 19 species studied.