Riboflavin in Blood Plasma of Some Brazilias Sxakes

Blood plasma from snakes of the Brazilian poisonous Bothrops and the non-poisonous Eudryas is yellow-green in color and when observed through ultraviolet light (mercury lamp with Wood’s filter) presents an intense green-blue fluorescence. This observation has suggested to us a detailed study of the plasma pigments of some snakes. When the blood plasma proteins are precipitated with 50 per cent methanol and dilute acetic acid in a hot water bath, the fluorescence of the filtrate is strongly intensified. The extraction of the methanol-water solution with light petroleum ether permit,s the separation of the yellow-green fluorescence from the blue. Some experiments were executed to identify this greenish fluorescence with riboflavin. Thus the fluorescence disappears by reduction and reappears by oxidation in air. Chloroform’ and ether do not extract the pigment. Dialysis experiments with cellophane bags demonstrated that only a small percentage of the flavin is in the free state. The flavin is adsorbed with lead sulfide and fullers’ earth and eluted by pyridine-wat’er-acetic acid mixture as in the case of riboflavin. Lumiflavin was obtained by irradiation of the watery extract after protein precipitation by heat. Potassium permanganate was ineffective in reducing the green fluorescence. The blue-violet fluorescence which is extracted by petroleum ether is resistant to hydrosulfite and probably belongs to the unknown blue fluorescent compound obtained by von Euler and Adler from the retina of fishes (1). On the other hand the blood plasma of the rattlesnake (Crotalus terrificus) and that, of the boipeva (Xenodon merremii) are practically devoid of flavin and the deproteinized extracts exhibit a blue-violet fluorescence. It is interesting to recall that Taborda and Taborda showed in 1941 that the venom of some species of Bothrops is rich in riboflavin and that of the rattlesnake presents only a bluish fluorescence (2).