Flavonoids from pollens and stigmas of male and female flowers of four species of the genusCucurbita

Summary Differences have been found between the flavonoid patterns of pollens and corresponding stigmas ofCucurbita pepo, C. maxima, C. moschata andC. ficifolia. The major flavonoids ahve been identified as isorhamnetin-3-O-rutinoside isolated from stigmas ofC. pepo is absent in this material.Acknowledgments. The author thanks Dr Chr. Karl (Weleda, Schwäbisch Gmünd) for a sample of isorhamnetin and Mr A. D'Urso (Botanic Institute, University of Catania) for help in acquiring the plant material.