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COMMUN~CATIONS TO TIII~:EDITOR
mated as cupric oxide, we are at present developing quantitative methods for these two drugs as well as sulfanilamide.
Vol. 61
end of the three-day incubation period were measured quantitatively with the thermoelectric turbidimeter described by Williams, et aL5 The MEDICINAL CHEMISTRY LABORATORY 1%’. A. Low galvanometer scale was set to read zero with the THESQUIBBINSTITUTE FOR MEDICAL RESEARCH uiiinoculated medium in the cell; a reading of 100 NEWBRUNSWICK, NEWJERSEY FRANKH. BERGEIM corresponds to complete opacity. RECEIVED SEPTEMBER 20, 1939 The “liver concentrate” was prepared in accordance with work of McDaniel, et al., and was kindly BIOTIN AS A GROWTH FACTOR FOR THE BUTYL furnished by Dr. Woolley. Biotin proved to be ALCOHOL PRODUCING ANAEROBES approximately 500 times as active as this concenSir: trate and it is evidently the only substance reRecently the “growth factor” requirements of quired in addition to the ordinary nutrients. the butyl alcohol-producing clostridia has excited Hydrolyzed casein evidently contains small considerable It has been found amounts of some substance which is in this case that several species of these organisms require a physiologically equivalent to biotin. Whether widely distributed organic acid, which cannot be the response which we have obtained is specific replaced by any known available growth factors. for biotin cannot a t present be stated. In any Using the test conditions of McDaniel, et al.,3 event, these results supply further evidence for and a culture of Clostridium biitylicum (Amer. the great physiological activity of biotin. Type Culture Coll. No. 6015), we have shown that We wish to express our thanks to Professor biotin4 is the only accessory substance required by Kogl, who kindly furnished us with the sample of this organism for luxuriant growth even on a biotin which made this work possible. synthetic medium. (5) William?, hIc.4listrr and Koehm J Rzol C h e m , 83, 315 The results of three tests axe given in Table I, (1929) the first two on the basal medium of McDaniel, DEPARTMENT OF CHEMISTRY ESMOND E. SNELL ROGER OF TEXAS J. WILLIAMS THEUNIVERSITY et a1.,3the third using a basal medium exactly the ArjsrIN TEXAS same except that an additional 0.1% asparagin RECEIVED OCTOBER13, 1939 was substituted for the casein hydrolysate Cultures 2 and 3 were subcultured from the unsupplemented tube of crilture I . Turbidities a t the ON THE ABSORPTION SPECTRUM OF HYPERICIN Sir: TABLE 1 The pigments of Hypericum perforaturn causing ,-Turbidities (galvanometer readings)--Subculturesphotosensitization in animals are spectroscopically Culture 2 Culture 1 (1-3 diln ) (1-2 diln ) Culture 3 closely related to irradiated oxypenicilliopsin from hydrolyzed hydrolped (undilut5d) Micrograms supplement per casein casein asparagin Penicillwpsis clavariaeformis [A. E. Oxford, Chem. cc of medium medium medium medium and Id.,57,975 (1938) ; C. Dh&&and V. Castelli, Biotin Supplement C. R. SOL. Bwl.,131, 669 (1939); C. DhkrC, ibid., 0.000000 15.0 17.0 2.2 131, 672 (1939)l. ,0000133 25.0 19.0 10.2 32.0 24.0 29.0 .0000266 Extracted hypericin was found chromato000053 46.0 34.0 54.0 graphically to consist of five components, and we .00010 60.0 49.0 75.0 have designated the two most abundant as X .00020 68 0 66.0 58.0 and IT. Samples were interchanged with Pro67.0 94.0 00066 81.0 fessor Raistrick, and component Y and irradiated Liver Concentrate Supplement oxypenicilliopsin appear very similar but not .0133 33.0 28.0 39.0 identical in chemical behavior. We wish at this 0333 52.0 39.0 60.0 juncture to supplement spectroscopic observations .0666 65.0 58.0 79.0 by Dht5-4 and Castelli: on these pigments. We 66.0 66.0 94.0 ,1332 have checked their absorption maxima in absolute 2664 67.0 74.0 94.0 6660 70.0 68.0 96.0 alcohol within IO A. and are in fair agreement as to the intensities. (1) Weizmann, et al , Biochem. J . , 31, 619 (1937). (21 Brown, Wood and Werkmau, S. Bacl., 86, 246 (1938). In Table I we show the effect of solvent com(3) McDaniet, Wonlleyanri Peterson, ;bid., 81, 269 (1989). position on the absorption maxima. Values are (4) Kagl and Tonnis, Z Bhysrol Ckeem., 248,43 (1936).
