Preparation and Properties of a Purified Ragweed Extract.

Abstract

Absorption spectra of ragweed pollen extracts prepared by a new electrophoretic method and by extracting the pollen with methanol are reported. Two main absorption bands were observed for crude aqueous extracts at 2600 A and 3600 A. Bands may be correlated with an impurity. The main components separated electrophoretically by the preparative method still showed a marked absorption band at 2600 A, but none at 3600 A. Ninety % methanol leached, lyophilized ragweed pollen extracts (MLL) show a marked depression of the 2600 A and the 3600 A bands. Biological activity of the essentially pigment-free prepn. is identical with the prepn. containing all of the pigment thus confirming the previous view that the pigments do not contribute substantially to biological activity. Electrophoretic analysis reveals that a new substantially colorless major component is formed, on removal of the pigment, with an electric mobility of approx. 0.3[mu]/sec. at pH 7.4.