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The concentration of ascorbic acid in the plasma was determined on four levels of ascorbic acid intake for seven day periods in 1946-47 and on three levels of ascorbic acid intake for ten day periods in 1947-48. The subjects, eight girls and eight boys, were 16 to 19 year old freshman students at Oregon State College. All of the food eaten by the subjects during the experimental periods was weighed and the quantities were recorded. The reduced ascorbic acid in the foods was determined after each meal by the method of Loeffler and Ponting (1942) and daily fasting plasma ascorbic acid values were determined by the micro-method of Farmer and Abt (1936). The data in this study were analyzed statistically by testing the significance of the differences between the means and by analysis of variance. The recommended allowance of the National Research Council (1945) for these subjects (80 mg for the girls and 100 mg for the boys) did not maintain mean plasma values as high as their respective means during the saturation period when they were receiving 200 mg of crystalline ascorbic acid in addition to the ascorbic acid from their food. On the recommended allowance all the mean plasma values for the girls were above 0.80 mg per cent, ranging from 0.83 to 1.07. The boys values ranged from 0.67 to 0.91 mg per cent; two out of seven values were below 0.80 mg per cent (data for one boy were excluded due to illness). A decrease in ascorbic acid intake to 10 mg less than the recommended allowance of the National Research Council made a statistically significant decrease in the plasma ascorbic acid concentration for only two of the eight girls and for one of the seven boys. The plasma ascorbic acid concentrations of these subjects showed individual variation even when the ascorbic acid intake was considered on the basis of mg of ascorbic acid per kg of body weight. The ten day experimental periods were more desirable than the periods of one week. This was particularly true for the saturation period when some of the subjects had been on diets low in ascorbic acid prior to the study. / Graduation date: 1949

Compounds belonging to the vitamin K family possess anti-hemorrhagic property, and are used in treating patients suffering from hypoprothrombinemia and obstructive jaundice. Some of these compounds also exhibit marked antimicrobial activity toward various microorganisms. Vitamin K₅, 4-amino-2-methyl- 1-naphthol hydrochloride, a water-soluble analog of vitamin K has been shown to possess such an antimicrobial activity toward many bacteria, molds, and yeasts. Much of the work reported in literature is on its use as a possible food preservative, and little information is available on the mechanism of its action on the microorganisms. In this study, the mode of action of vitamin K₅ on Saccharomyces cerevisiae was investigated. Its effect on yeast cells, with and without sodium chloride; its color reactions with trisodium pentacyanoaminoferroate; its influence on certain enzyme systems of the yeast cell as indicated by 2, 3, 5-triphenyltetrazolium chloride; and the antagonistic effect of cysteine hydrochloride toward it were studied. In addition, the sulfhydryl groups of yeast cells were estimated by amperometric titration, and carbon dioxide production by yeast cells from different substrates was determined manometrically. The results showed that vitamin K₅ did not inhibit the yeast cells immediately on coming into contact with them. Vitamin K₅, with sodium chloride, produced 76 percent inhibition of yeast cells in 50 minutes as compared to 50 percent inhibition produced during the same time when used alone. Cysteine hydrochloride reacted with vitamin K₅ and stopped it from producing a blue color with trisodium pentacyanoaminoferroate. Cysteine hydrochloride also antagonized the antifungal activity of vitamin K₅, since in its presence vitamin K₅ failed to stop the reduction of 2, 3, 5-triphenyltetrazolium chloride by dehydrogenase systems. The yeast cells which had previously been inhibited by vitamin K₅ could not be revived by treatment with cysteine hydrochloride. These cells had developed a dark pink color which could not be removed by repeated washings. The sulfhydryl groups of yeast cells were reduced quantitatively when they were exposed to vitamin K₅. The reduction was not immediate and followed the same pattern as in case of total counts. Higher concentrations of vitamin K₅ inhibited carbon dioxide production by yeast cells to a greater extent in the three substrates used in this study. The action of vitamin K₅ is not immediate, the coloration picked up by the cells cannot be washed off, and its action is hastened in the presence of sodium chloride. All these seem to indicate that permeability of the cell is involved in some manner in the inhibition process. Higher concentrations of vitamin K₅ produce greater inhibition which shows that this compound also combines with sulfhydryl groups of the yeast cells. These findings suggest that the mode of action of vitamin K₅ is most likely due to an alteration of cell permeability as well as by combining with sulfhydryl groups of the yeast cells. / Graduation date: 1963

Vitamin K₅, 4-amino-2-methyl-1-naphthol hydrochloride, a water soluble analog of vitamin K has been shown to possess an antimicrobial activity toward many bacteria, molds, and yeast. Much of the work reported in the literature is on its use as a food preservative, and it was the purpose of this study to investigate some of the factors which might affect the antimicrobial activity of vitamin K₅ in order to add insight into its more effective use as a food preservative. Pure cultures of Escherichia coli, Bacillus subtilis, Proteus vulgaris, Staphlococcus aureus, and Pseudomonas fluorescens were utilized. The effect of the method of application of vitamin K₅ on Escherichia coli; the effect of purity of vitamin K₅ against Escherichia coli; the bactericidal concentrations required for Escherichia coli, Bacillus subtilis, Proteus vulgaris, Staphlococcus aureus, and Pseudomonas fluorescens; the effect of an absence of oxygen; the effect of contact time with Escherichia coli; the effect of initial count/ml of Escherichia coli; and the synergistic action in combination with propylene glycol were studied. The results demonstrated that air oxidation of vitamin K₅ was necessary to obtain maximum inhibitory activity against Escherichia coli. The use of white, crystalline vitamin K₅ synthesized in the laboratory, as compared to partially oxidized commercial preparations, gave better results against Escherichia coli. It was shown that some species variation, with the five microorganisms tested, did exist with respect to the antimicrobial activity of vitamin K₅. The bactericidal concentrations ranged from 60 ppm for Staphlococcus aureus to 220 ppm for Escherichia coli, using an initial count of 160,000 to 200,000 cells/ml and a contact time of 12 hours in Bacto-nutrient broth. The gram-positive bacteria tested were more susceptible to the antimicrobial activity of vitamin K₅ than the gram-negative bacteria tested. In the studies conducted under nitrogen atmosphere the percent inhibition showed an inverse relation to the bactericidal concentrations required for complete inhibition in studies conducted under air atmosphere. This finding suggested that there might be different factors responsible for inhibition depending on the species of bacteria being tested and also might help explain the difference in concentrations necessary for inhibition. Cells of Escherichia coli were not inhibited immediately on coming into contact with vitamin K₅. Fifty percent inhibition occurred after 25 minutes. A rapid inhibition rate was maintained until approximately 90 percent inhibition occurred, afterwhich, a rapid decrease in the rate of inhibition was noted. An increase in the initial number of cells of Escherichia coli utilized required an increase in the concentration of vitamin K₅ for complete inhibition, although the concentration of vitamin K₅ was not the limiting factor. A synergistic effect does exist between vitamin K₅ and propylene glycol, and the bactericidal concentrations necessary for the different bacteria can be reduced depending on the species of bacteria and the concentration of propylene glycol utilized. / Graduation date: 1965

Graduation date: 1943

Graduation date: 1944

Graduation date: 1945

Typescript. / Thesis (Ph. D.)--University of Hawaii, 1966. / Bibliography: leaves [92]-94. / ix, 94 l illus., tables

Thesis (Ph. D.)--University of Chicago, 1921. / "Private edition, distributed by the University of Chicago libraries, Chicago, Illinois." "Reprinted from the Journal of biological chemistry, vol. XLIV, no. I, October 1920 and vol. XLVIII, no. 2, October 1921." Also available on the Internet.

Thesis--København. / "Litteraturfortegnelse": p. [158]-165.