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Forms of vitamin K: menadione (A), phylloquinone (B), menaquinone-4 (C), and menaquinone-n+1 (D). Reproduced from reference (2) with permission.
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Vitamin K exists in the food supply as phylloquinone, a plant-based form and as menaquinones (MKs), a collection of isoprenologues mostly originating from bacterial synthesis. Although multiple bacterial species used as starter cultures for food fermentations synthesize MK, relatively little is known about the presence and distribution of MK in the...
Contexts in source publication
Context 1
... dried chick feed was produced by Bacillus cereus (4). Most bacteria are now known to synthesize a limited set of naphthoquinones, which share the same 2-methyl-1,4-naphthoquinone ring but differ in the length of an isoprenoid side chain attached at the 3-position, which generally ranges from 5 to 13 prenyl units (each having 5 carbons) in length (Fig. 1). These compounds are known as long-chain MKs or MK-n; n representing the number of prenyl units (e.g., MK-7 is the term for 2-methyl-3-heptaprenyl-1,4-naphthoquinone). The 2-methyl-1,4-naphthoquinone ring, also known as menadione or vitamin K-3, is common to all forms of vitamin K. However, PK differs from MKs by virtue of a phytyl ...
Context 2
... use 2 distinct biochemical pathways for MK synthesis (Supplemental Figure 1), both of which have been described in detail elsewhere (6)(7)(8). In the pathway used by lactic acid bacteria (LAB) that are commonly used in industrial food fermentations, the napthoquinone ring is synthesized from chorismate derived from the shikimate pathway by a series of enzymes encoded by men genes. ...
Citations
... Furthermore, quinones find their place in natural products and the food industry. They are integral to various natural products, including essential vitamins like vitamin K. Additionally, their antimicrobial properties make them valuable in the food industry as additives and preservatives [31]. ...
This review explores the synthesis and diverse applications of heterocyclic quinones, highlighting versatile methods such as Diels-Alder reactions. Heterocyclic quinones impact electrochemistry, batteries, textiles, and medicine, particularly in cancer treatment. Their antioxidant properties, exemplified by ubiquinone, are crucial for cellular protection. Quinones play essential roles in photography, organic synthesis, polymer chemistry, and enhancing conductivity. They act as catalysts, indicators, and probes in various chemical and analytical processes. The review emphasizes their potential in cancer therapy, enzyme inhibition, antibacterial, antifungal, and cytotoxic activities. Serving as a valuable resource, it concludes by acknowledging the significant contributions of heterocyclic quinones to scientific, industrial, and creative advancements.
... Along with aiding in blood clotting, vitamin K also supports bone health by regulating the activity of osteocalcin, a protein essential in bone development. Vitamin K is offered as a food additive in two different forms: K1 (phylloquinone) and K2 (which is made up of numerous MKs, or menaquinones) (Walther et al. 2013). Vitamin K plays a crucial role in facilitating the synthesis of proteins and other fundamental physiological processes. ...
Vitamins and minerals are receiving a lot of attention for their potential to boost the immune system, particularly in relation to the COVID-19 pandemic. Although these nutrients do not act as a cure or preventative measure for the virus, their role in boosting the immune system is essential for fighting infections such as respiratory illnesses, including COVID-19. Vitamin C is recognized for its ability to act as an antioxidant, stimulating the development of white blood cells and antibodies, which strengthens the body's ability to defend itself. Likewise, vitamin D is crucial for the functioning of the immune system, and a lack of it has been associated with a higher risk of getting sick. Vitamin A helps maintain the health of skin and mucous membrane cells, acting as a protective shield against harmful pathogens. Zinc and selenium are necessary for the proper operation of immune cells, while vitamin E serves as an antioxidant, shielding cells from harm. Although it is ideal to have a well-rounded diet that is high in these nutrients, it is important to recognize that excessive supplementing may not provide any extra advantages and may even be harmful. The focus should be on getting a variety of nutrients from a wide range of foods such as fruits, vegetables, nuts, seeds, and lean meats. Amid the COVID-19 pandemic, it is crucial to prioritize compliance with public health precautions including vaccination, hygiene protocols, and maintaining physical distance. It is recommended to seek guidance from medical professionals before making any dietary changes or starting on any supplements, especially for those with pre-existing health issues. Recognizing the importance of vitamins and minerals in supporting the immune system contributes to a comprehensive approach to staying healthy during difficult times.
... Vitamin K2 (Menaquinone, MK) is a class of fat-soluble menadione compounds with the structure of a 2-methyl-1,4-naphthoquinone ring joined by an isoprene side chain at the C-3 position [1,2]. There are 14 subtypes of vitamin K2 based on the number of isoprene residues on the side chain, known as MK-n [3,4]. Menaquinone-7 (MK-7), which has seven isoprene side chain [5], has key responsibilities in bone mending, avoiding cerebrovascular and cardiovascular disorders, and attacking cancer cells, Alzheimer's disease, and Parkinson's disease [6][7][8][9][10][11]. ...
Menaquinone-7 (MK-7) is an important class of vitamin K2 that is essential in human health and can prevent osteoporosis and cardiovascular disease. However, due to the complex synthesis pathway, the synthesis efficiency is low. The main objective of this study was to explore the effect of enhanced supply of precursors in Bacillus natto. Three precursors of pyruvate, shikimic acid, and sodium glutamate were chosen to investigate the effect of enhanced supply of precursors on MK-7 synthesis. Then, the optimal concentrations, different combinations, and different adding times were systematically studied, respectively. Results showed that the combination of shikimic acid and sodium glutamate could boost MK-7 production by 2 times, reaching 50 mg/L of MK-7 titer and 0.52 mg/(L·h) of MK-7 productivity. Furthermore, adding shikimic acid and sodium glutamate initially and feeding pyruvate at 48 h and 72 h increased MK-7 production to 58 mg/L. At the same time, the expression of the three related genes was also significantly upregulated. Subsequently, a new fermentation strategy combining the precursors enhancement and product secretion was proposed to enhance MK-7 yield and MK-7 productivity to 63 mg/L and 0.45 mg/(L·h). This study proposed a new fermentation regulation strategy for the enhancement of vitamin K2 biosynthesis.
... Menaquinones are isoprenoid quinones and are constituents of bacterial plasma membranes, where they play important roles in electron transfer and oxidative phosphorylation, particularly in anoxic conditions (26,27). This group of compounds are also considered a vitamin (vitamin K 2 ), as they are essential dietary supplements for humans and animals (28,29). The role of the vitamin K 2 is post-transla tional modification of proteins, mainly those involved in blood coagulation (30). ...
Axenic Aedes aegypti mosquitoes were colonized with bacteria from an environmental water source to compare the midgut microbiota acquired from the wild to the microbiome of insectary-reared mosquitoes, specifically over the course of blood meal digestion. 16S rRNA gene sequencing revealed that diversity, composition, and community turnover of the midgut microbiomes were distinct between the insectary and environmental groups, with the environmental microbiomes having a greater diversity and larger temporal shifts over the course of the blood meal. Metagenomic prediction from the 16S rRNA gene sequence data pointed to metabolic processes such as vitamin biosynthesis, fatty acid recycling, and fermentation pathways differentiating the functional potential of the two different microbiomes. To further test if we could identify functional traits that distinguished the two microbiomes, we performed a culture-based assay. Culturable bacteria were more abundant in the insectary microbiomes and there was very little overlap in the taxonomy of bacteria recovered from the insectary or environmental groups. The ability of the isolates to lyse blood cells was determined on blood agar plates, and only isolates from the environmental microbiome harbored the ability to perform hemolysis in culture. These data support that the differences in taxonomy observed between the two different microbiomes also result in differences in the functional potential of the community. Thus, this study demonstrates the power of the axenic mosquito model to shed light on the community ecology of the mosquito microbiome, and the potential to better represent the microbiomes of wild mosquitoes in a laboratory setting.
IMPORTANCE
The blood meal of the female mosquito serves as a nutrition source to support egg development, so is an important aspect of its biology. Yet, the roles the microbiome may play in blood digestion are poorly characterized. We employed axenic mosquitoes to investigate how the microbiome differs between mosquitoes reared in the insectary versus mosquitoes that acquire their microbiome from the environment. Environmental microbiomes were more diverse and showed larger temporal shifts over the course of blood digestion. Importantly, only bacteria from the environmental microbiome performed hemolysis in culture, pointing to functional differences between bacterial populations. These data highlight that taxonomic differences between the microbiomes of insectary-reared and wild mosquitoes are potentially also related to their functional ecology. Thus, axenic mosquitoes colonized with environmental bacteria offer a way to investigate the role of bacteria from the wild in mosquito processes such as blood digestion, under controlled laboratory conditions.
... Natural vitamin K exists as two vitamers: vitamin K1 (known as phylloquinone (PK)) found in leafy green vegetables [20] and vitamin K2 (a group of menaquinones, often denoted MKs) ( Figure 1) found in fermented foods and foods of animal origin [21]. Vitamin K also exists in the gut microbiota to an unknown extent, formed by intestinal bacteria [22,23]. ...
The observation that the extent of artery calcification correlates with the degree of atherosclerosis was the background for the alternative treatment of cardiovascular disease with chelator ethylenediamine tetraacetate (EDTA). Recent studies have indicated that such chelation treatment has only marginal impact on the course of vascular disease. In contrast, endogenous calcium chelation with removal of calcium from the cardiovascular system paralleled by improved bone mineralization exerted, i.e., by matrix Gla protein (MGP) and osteocalcin, appears to significantly delay the development of cardiovascular diseases. After post-translational vitamin-K-dependent carboxylation of glutamic acid residues, MGP and other vitamin-K-dependent proteins (VKDPs) can chelate calcium through vicinal carboxyl groups. Dietary vitamin K is mainly provided in the form of phylloquinone from green leafy vegetables and as menaquinones from fermented foods. Here, we provide a review of clinical studies, addressing the role of vitamin K in cardiovascular diseases, and an overview of vitamin K kinetics and biological actions, including vitamin-K-dependent carboxylation and calcium chelation, as compared with the action of the exogenous (therapeutic) chelator EDTA. Consumption of vitamin-K-rich foods and/or use of vitamin K supplements appear to be a better preventive strategy than EDTA chelation for maintaining vascular health.
... Vitamin K 2 (also called menaquinone-n: MK-n) is produced by microorganisms, such as intestinal bacteria, and is found in animals and fermented foods ( Figure 1). 11 Another form is menadione (vitamin K 3 ), which is a synthetic product and has no side chain. Vitamin K 3 is converted to menaquinone-4 in the tissues of birds and mammals and widely used as a vitamin K additive in animal feed ( Figure 1). ...
... Compound 7 was prepared by a similar procedure to that for 4 but with compound 29 instead of compound 26 as a reactant. Yield: 15%; yellow oil; 1 112.8, 115.7, 123.8, 124.6, 126.6, 130.0, 134.2, 139.4 (11). Compound 11 was prepared by a procedure similar to that in the case of 4 but with compound 33 instead of compound 26 as a reactant. ...
From our compound library of vitamin K derivatives, we found that some compounds exhibited anti-SARS-CoV-2 activity in VeroE6/TMPRSS2 cells. The common structure of these compounds was menaquinone-2 (MK-2) with either the m-methylphenyl or the 1-naphthyl group introduced at the end of the side chain. Therefore, new vitamin K derivatives having more potent anti-SARS-CoV-2 activity were explored by introducing various functional groups at the ω-position of the side chain. MK-2 derivatives with a purine moiety showed the most potent antiviral activity among the derivatives. We also found that their mechanism of action was the inhibition of RNA-dependent RNA polymerase (RdRp) of SARS-CoV-2. The chemical structures of our compounds were completely different from those of nucleic acid derivatives such as remdesivir and molnupiravir, clinically approved RdRp inhibitors for COVID-19 treatment, suggesting that our compounds may be effective against viruses resistant to these nucleic acid derivatives.
... Earlier data on vitamin K intakes in Nordic and Baltic countries has been reviewed by EFSA (3). Results on dietary intake should be interpreted cautiously as food composition databases may have limitations and vitamin K content data mostly include only phylloquinone, not menaquinones (14,16). In addition, the relative bioavailability of different forms of vitamin K is poorly known and limits the interpretation of summed intakes of different vitamin K forms. ...
Vitamin K occurs in dietary supply in two major forms: phylloquinone (vitamin K1) and menaquinones (collectively referred as vitamin K2). Phylloquinone is derived from plants. There are at least 10 forms of menaquinones varying in chain length and they are produced by bacteria except menaquinone-4. Menaquinone-4 is formed from phylloquinone or other menaquinone forms. Phylloquinone is considered to be the major contributor and menaquinones are thought to contribute less to vitamin K intake in Western diets. However, less is known about the content of menaquinones than phylloquinones in foods.
Vitamin K is known to function as an enzymatic cofactor in the gamma-carboxylation of vitamin K dependent proteins (VKDPs). Hepatic VKDPs are involved in coagulation. Extrahepatic VKDPs have a role e.g. in bone health and vascular calcification. However, the amount of vitamin K needed for optimal functioning of the different VKDPs is not known.
... Vitamin K 2 is also produced in the gastrointestinal tract by the resident bacterial flora, but their bioavailability is low. [5][6][7] Vitamins K 1 and K 2 have different tissue distribution and bioavailability. Vitamin K 1 and MK-4 were present in the plasma for 8-24 hours after administration. ...
... Pathways upregulated in the bacterial community within water column in the control group (clear water treatment) have important role in bacterial metabolism and overall cell fitness because menaquinones are involved in the regulation of membrane fluidity (Flegler, Kombeitz & Lipski, 2021), mediation of electron transport between various enzymes (van Beilen & Hellingwerf, 2016;Boersch et al., 2018), and the generation of ATP (Boersch et al., 2018). Additionally, menaquinones serve as crucial source of essential vitamin (vitamin K 2 ) for animals, where vitamin K 2 is needed various physiological processes, including in blood coagulation (Walther et al., 2013). Probiotic introduction induced upregulation of nutrient (glucose and fatty acid) metabolism pathways in the water column, thereby removing organic matter load and ensuring better water quality (Hlordzi et al., 2020). ...
Biofloc technology improves water quality and promote the growth of beneficial bacteria community in shrimp culture. However, little is known about the bacteria community structure in both water and gut of cultured organisms. To address this, the current study characterised the metagenomes derived from water and shrimp intestine samples of novel Rapid BFT TM with probiotic and clearwater treatments using 16S V4 region and full length 16S sequencing. Bacteria diversity of water and intestine samples of Rapid BFT TM and probiotic treatments were similar. Based on the 16S V4 region, water samples of >20 μm biofloc had the highest abundance of amplicon sequence variant (ASV). However, based on full length 16S, no clear distinction in microbial diversity was observed between water samples and intestine samples. Proteobacteria was the most abundant taxon in all samples based on both 16S V4 and full length 16S sequences. Vibrio was among the highest genus based on 16S V4 region but only full length 16S was able to discern up to species level, with three Vibrio s identified— V. harveyi , V. parahaemolyticus and V. vulnificus . Vibrio harveyi being the most abundant species in all treatments. Among water samples, biofloc water samples had the lowest abundance of all three Vibrio s, with V. vulnificus was present only in bioflocs of <20 μm. Predicted functional profiles of treatments support the beneficial impacts of probiotic and biofloc inclusion into shrimp culture system. This study highlights the potential displacement of opportunistic pathogens by the usage of biofloc technology (Rapid BFT TM ) in shrimp culture.
... Both forms are found in nature, but as K1 is found mainly in green plants and algae, K2 is synthesized by bacteria and can be found in both animal products such as meat, cheese or fermented food products, and in the human digestive tract [1]. Owing to the presence of the naphthoquinone ring, both forms exhibit numerous and more or less specific biological activities, the impact of which on the human body was underestimated not long ago [2,3]. However, only the results published at the beginning of the 21st century, proving the relationship between senile diseases and vitamin K deficiency, fully reveal its importance [2,4]. ...
... However, only the results published at the beginning of the 21st century, proving the relationship between senile diseases and vitamin K deficiency, fully reveal its importance [2,4]. Taking into account the main health problems of the modern world and the fact that aging of the population is one of the dominant trends in the 21st century, the most important biological properties are the prevention of osteoporosis and cardiovascular diseases as well as the reduction in the risk of cancer [3][4][5][6][7]. According to [2][3][4][5][6]8] these properties are more specific to MK-7, hence the growing interest in determining this with modern requirements, and its subsequent quantitative analysis using the recently developed and validated rapid LC-MS/MS-based method. ...
... Taking into account the main health problems of the modern world and the fact that aging of the population is one of the dominant trends in the 21st century, the most important biological properties are the prevention of osteoporosis and cardiovascular diseases as well as the reduction in the risk of cancer [3][4][5][6][7]. According to [2][3][4][5][6]8] these properties are more specific to MK-7, hence the growing interest in determining this with modern requirements, and its subsequent quantitative analysis using the recently developed and validated rapid LC-MS/MS-based method. As the optimized method proved to be an effective and useful diagnostic tool, it was used in our laboratory (Research and Development Centre, ALAB, Lublin, Poland) for the routine analyses for a two-year period to obtain information on the content and distribution of K2MK-7 in the Polish population by different gender and different age groups. ...
Biological properties of menaquinone-7, one of the vitamin K2 vitamers (K2MK-7), both those proven and those that remain to be investigated, arouse extensive interest that goes beyond the strictly scientific framework. The most important of them is the prevention of age-related diseases, considering that we live in the times identified as the era of aging societies and many people are exposed to the vitamin K2MK-7 deficiency. Therefore, an effective analytical protocol that can be adopted as a diagnostic and preventive analytics tool is needed. Herein, a simple sample preparation method followed by the liquid chromatography-tandem mass spectrometry-based method (LC-MS/MS), was used for the selective and sensitive determination of K2MK-7 in serum samples. Under the optimized conditions, using 500 µL of serum and the same amount of n-hexane, the reproducibility and the accuracy were obtained in the ranges of 89–97% and 86–110%, respectively, and the limit of detection value was 0.01 ng/mL. This method was used for the routine analysis. Statistical interpretation of the data from 518 samples obtained during 2 years of practice allowed for obtaining information on the content and distribution of K2MK-7 in the Polish population, broken down by the sex and age groups.
