Abstract
This note∗ reports the isolation of flavin elaborated by C. diph-iheriae, strain No. 3203, grown in synthetic medium. Flavin was separated by ultrafiltration from the toxin and extracted by chloroform from the filtrate after it had been treated with ether to remove the porphyrins soluble in ether and any other ether-soluble substances. The chloroform extract was subjected to chromatographic analysis and the pigment solutions that were recovered from the column were centrifugalized.
The green fluorescence of the untreated filtrate suggests the presence of flavin. Others 4 5 have also noted this fluorescence. The chloroform extract was analyzed on a column of Brockmann's standardized aluminum oxide. When the column was examined in the light of a Hanovia analyzing lamp, several fluorescing zones were observed. The material in the lowest zone, of a brilliant canary yellow fluorescence, was washed from the coIumn with chloroform and, in this solution, fluoresced with a yellow-green light that changed to blue when the solution was exposed to daylight. The material in the zone above this, which fluoresced with a bright blue light, was elutriated from the column with methyl alcohol and fluoresced in this solution with an intense sky blue light which changed to yellow when the solution was made alkaline and remained so when left standing in daylight. The addition of a reducing agent, sodium hydrosulfite, quenched the fluorescence which was restored when the solution was oxidized by shaking in air.
Uninoculated synthetic medium, when poured on the colunmn, gave a very feeble fluorescence not at all similar to the brilliant yellow and blue light described above.
Get full access to this article
View all access options for this article.