Factors Affecting the Antimicrobial Activity of Vitamin K51

Abstract

, AND H. Y. YANG. Factors affecting the antimicrobial activity of vitamin K5. Appl. Microbiol. 13:766-770. 1965.-Pure cultures of Escherichia coli, Bacillus subtilis, Proteus vulgaris, Staphylococcus aureus, and Pseudomonasfluorescens were used in this investigation. The bactericidal concentrations of vitamin K5 required for E. coli, B. subtilis, P. vulgaris, S. aureus; and P. fluorescens; the effect of an absence of oxygen; the effect of contact time with E. coli and S. aureus; and the effect of initial counts per milliliter of E. coli were studied. The bactericidal concentrations ranged from 60 ppm of K5 for S. aureus to 220 ppm for E. coli, with an initial count of 160,000 to 200,000 cells per milliliter and a contact time of 12 hr in nutrient broth. The gram-positive bacteria tested were more susceptible to the antimicrobial activity of vitamin K5 than the gram-negative bacteria. In the studies conducted under nitrogen atmosphere, the per cent inhibition showed an inverse relationship 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 it also might help explain the difference in concentrations necessary for inhibition. Cells of E. coli and S. aureus were not inhibited immediately on coming into contact with vitamin Kr; 50% inhibition occurred after 25 and 32 min, respectively. A rapid inhibition rate was maintained until approximately 90% inhibition occurred, after whch a rapid decrease in the rate was noted.

Photoactivities of Vitamin K Derivatives and Potential Applications as Daylight-Activated Antimicrobial Agents

“…Vitamin K 1–5 (VK 1–5 ) are compounds with structures similar to anthraquinone derivatives containing aromatic rings and ketone structure, except Vitamin K 4 (VK 4 ) and vitamin K 5 (VK 5 ), which are the reduced ketone derivatives of vitamin K 3 (VK 3 ). − Vitamin K 1 (VK 1 ) is a natural vitamin in green leafy vegetables with a low toxicity and has been used as an oral nutrient supplementary or injection to prevent bleeding caused by vitamin K deficiency . Vitamin K 2 (VK 2 ) is also a natural product in fermented food or animal food and functions similarly as VK 1 in the human body .…”