THERE is some vagueness as to the exact scope of the so-called Pauly reaction, such as is given by histidine with diazotised sulphanilic acid. In the broad sense, it might be considered to characterise any substance reacting in a weak alkaline solution to give the characteristic pink or red colour. In the particular sense however it is often now taken to indicate a substance reacting with the reagents studied in detail by Koessler and Hanke [1919; see also Hunter, 1922;1925].Jansen and Donath [1926] Hence we were correct in attributing our previous 3 % to impurities.Nevertheless, in essence the opinion as expressed at the British Association Meeting is correct, namely that the vitamin would interact with the diazoreagent to give a pink colour at a more alkaline reaction than the one employed in the Koessler and Hanke method. We have delayed publication on this question for over two years in the effort to collect conclusive evidence, and we are now presenting shortly some of our data (as a preliminary step). Two circumstances have assisted our progress: (1) the realisation that rather fine shades of alkalinity 1 It should have been added "in this sense."
have led to a revision of some of the facts published from other laboratories, which eliminates the main differences between ourselves and them. Valuable help has also been obtained from X-ray analysis methods. So that in our opinion, there is now no valid reason for questioning the view that vitamin B1 has been isolated, though certain details have not yet been settled. HISTORICAL. Jansen and Donath [1926] were the first to isolate crystalline vitamin B1 preparations. These were not quite pure; they contained substances precipitable by mercuric sulphate in acid solution, which is not a property of the vitamin
IN this paper are described improved methods of concentrating torulin to an activity of 0O5-1-0 mg. per day and some of the experimental evidence upon which the better methods are-based. Torulin is here defined as the factor in yeast curative of symptoms in pigeons of head retraction induced by feeding upon polished rice. The work forms a continuation of that previously published [Kinnersley and Peters, 1925]. Discussion of the relation of this work to that of others is postponed to the end of this paper. EXPERIMENTAL.The methods of testing have been those previously described, and the activity (curative and protective) is given throughout in mg. per pigeon per day (day-dose). Previous methods of concentrating to an activity of 1-0 mg. involved a preparation of the Osborne-Wakeman aqueous extract from baker's yeast, and the successive removal of precipitates with neutral lead acetate and acid mercuric sulphate. At this stage in the earlier experiments, barium sulphide together with barium sulphate precipitated in the solution was used to clear metals and certain colloidal matter before charcoal treatment. Subsequently this was discarded owing to the tedium of filtration. Instead, the filtrate from the mercuric sulphate precipitate was brought to PH 5 0 approx., any precipitate which appeared being removed. Charcoal was then stirred into the solution, and the antineuritic substance together with impurities removed from the charcoal by extraction with acid 50 % alcohol. The idea which guided these experiments was based upon the belief that the earliest possible treatment with charcoal shortened stages in which large volumes of solution must be handled. Working upon the small scale and with care in the use of the mercury reagent, satisfactory concentrates can be prepared in this way. The concentrates so obtained can be further purified by alcohol fractionation. Exp. 1 gives the details of one such experiment and exemplifies the technique. 100 cc. 55 % alcohol by volume containing 1 cc. conc. HCI %. The organic solids present in the combined alcoholic extract were 2-850 g. The solutions were concentrated to about 5 cc. in vacuo at about 600, and 45 cc. 97 % alcohol were added, making an alcohol concentration of 87 %1. The precipitate was removed by the centrifuge and washed with 87 % alcohol. The further treatment is sketched below: Centrifugate 87 % alcob Test 500 + 700, 700 doses Alcohol removed, 50 cc. water added, and lead acetate (25 %) until no further precipate r Centrifugate. Passed H2S 2 hours and washed precipitate with PbAc preci water containing trace of acetic acid r Centrifugate. Boiled off H;S and concentrated in vacuo to 4 cc.; Sulphide p added 95 cc. alcohol Centrifugate Test 600 doses Concentrated with 1 cc. conc. HC1 (to remove acetic) to dark 95 % alcoh brown gum. Extracted with hot 97 % alcohol. Washed the precipitate with 97 % alcohol hol precipitate pitate recipitate hol precipitate Centrifugate. Removed alcohol and added NaOH (20 %) to 97 % alcohol precipitate PER 5*0. To the volume 10 cc. ad...
INTRODUCTION. THE observations embodied in this communication arose in an attempt to discover why some cases of opisthotonus in rice-fed birds could be cured by giving glucose alone [Kinnersley, Peters and Reader, 1928]. This fact, beyond proving incontestably that all symptoms of opisthotonus produced by rice feeding were not due to lack of vitamin B1, suggested an intimate relation between the symptoms and some phase of carbohydrate metabolism. It seemed possible that investigation of the relation between these symptoms and carbohydrate metabolism might shed light upon the metabolic lesion in avitaminosis proper. In this paper, it is shown that more lactic acid is present in the brain of a pigeon suffering from "avitaminous" opisthotonus than in that of the normal'.-HISTORICAL. The brain in avitaminosis B. Though the lactic acid content of the brain in avitaminosis has not been investigated, estimations of other constituents have been made. Schaumann [1910] found only slight differences between the phosphoruis content of the brains in normal and rice-fed pigeons. Funk [1912] found a diminution in ritrogen and phosphorus and Findlay [1921] a decrease in nucleic acid content, whereas Hotta 11923] and Verzar, Kokas and Arvay [1924] claimed an increase in cholesterol content, and more recently, Ljubarskaja [1928] an increase in creatine. 1 We have purposely avoided using the term "beriberi pigeon" throughout owing to the claim by McCarrison [1928] that true beriberi can be produced in pigeons, and that this differs from simple polyneuritis. A preliminary account of the work appeared in Chem. Ind. (1929), 48, 360.
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