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
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/26775 |
| Date | 22 July 1963 |
| Creators | Rasulpuri, Muhammad Latif |
| Contributors | Yang, Hoya Y. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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