Egg-white as a source of the anti-dermatitis vitamin B2

Abstract

IT has already been recorded that the fresh egg-white of the hen's egg contains vitamin B2 unaccompanied by the antineuritic vitamin B1 [Chick and Roscoe, 1929, 1]. In this property egg-white stands alone amongst the foodstuffs hitherto examined, for in all others in which vitamin B2 has been found, vitamin B has also been present, although the relative amounts of the two have shown a wide variation [Aykroyd and Roscoe, 1929;Roscoe, 1930].This unusual property makes egg-white a valuable material for use in the investigation of the various members of the B group of vitamins. It has, therefore, seemed worth while to publish a short account of the evidence upon which the above statement is based.Vitamin B1 deficiency of egg-white. If young rats immediately after weaning receive an artificial diet deprived of vitamin B1, but otherwise complete and containing egg-white as source of protein and of vitamin B2 [see Chick and Copping, 1930, 3, p. 1765, Diet II], growth takes place for 2-3 weeks, after which appetite fails and a decline in weight sets in. If this is not checked death will often follow and will be preceded by the paralysis characteristic of vitamin B1 deficiency, which is promptly cured if vitamin B1 is given. If, at the point where weight has become stationary or has begun to decline, vitamin B1 is given as a daily dose of some foodstuff containing it, or as Peters's antineuritic concentrate, growth is immediately restored and the gain in weight will be in relation to the amount of vitamin B1 administered. These facts have been applied in a method for estimation of vitamin B1 in foodstuffs [Chick and Roscoe, 1929, 1].Vitamin B2 content of egg-white. The content of vitamin B2 can be estimated by measuring the minimal daily dose required to restore growth which has ceased in young rats after short periods, 1-2 weeks, on a synthetic diet containing vitamin B1 and lacking only vitamin B2 [Chick and Roscoe, 1928]. It has been found that a daily dose of 2-5-5-0 g. of fresh, cooked, egg-white (dry weight 0-3-0-6 g.) or of an

The alcohol-solubility of the anti-dermatitis, more heat-stable vitamin B2 constituent of the vitamin B complex

“…For example, this vitamin was found by Levene [1928] to be sensitive to the action of nitrous acid; but completely resistant by Chick and Roscoe [1929] and Narayanan and Drummond [1930]. Chick and Roscoe [1930] and Chick and Copping [1930] have found vitamin B2 to be destroyed by action of alkalis (PH 9-10) at high temperatures 120-125°; Reader [1929] and Narayanan and Drummond [1930], on the other hand, have found it to be resistant.…”

“…It is probable that in the vitamin tests of these authors the growth of the experimental rats was limited by the amount of vitamin B1 present, this factor being soluble in 70 % alcohol, but there can be little doubt that vitamin B2 was abundantly present in the precipitate. Chick and Roscoe [1929] Narayanan and Drummond [1930] have recently published results differing somewhat from the above. They employed alcoholic fractionation to prepare a strong vitamin B2 concentrate from brewer's yeast.…”

“…(Received October 28th, 1930. ) THE relative insolubility in alcoholic solutions of 70 % strength upwards of vitamin B2 as compared with the antineuritic vitamin B1, has been shown by several independent workers using materials derived from different sources [Goldberger et al, 1926;Sherman and Sandels, 1929;Chick and Roscoe, 1929;Narayanan and Drummond, 1930]. Osborne and Wakeman [1919] used alcohol fractionation in the preparation of their "vitamin B" concentrate.…”

“…We used the solution (Fraction C) obtained by decomposition of the precipitate formed (at PH 7.5) when basic lead acetate is added to the extract obtained by boiling washed brewer's yeast in 0*01 % acetic acid solution [Chick and Roscoe, 1929]. The precipitate was decomposed and lead removed by H2S, after acidification with sulphuric acid, and the filtrate concentrated on a water-bath until the equivalent of 745 g. yeast (dry weight) was contained in 3050 cc.…”

“…(Fraction C), the PH being 1-5. The vitamin B2 content of this and the succeeding fractions was estimated by the method previously described [Chick and Roscoe, 1928]. Before testing, the solution was brought to ca.…”