Phylloquinones formula

Chemical Name 2-Methyl-3-(3,7,11,1 5-tetramethvl-2-hexadecenvD-1,4-naphthalenedione Common Name Vitamin K, phytomeanadion, phylloquinone Structural Formula ... 

The vitamin K requirement is met from the diet (vitamin Ki) and microorganisms in the intestine (vitamin K2). The richest dietary source of vitamin K is green leafy vegetables but it is also present in meat and dairy produce. The structural formulae of vitamin Ki (phylloquinone) and vitamin K2 (menaquinone) are given in Figure 15.15. It was discovered in 1929 by Henrik Dam in Copenhagen, who discovered that it was necessary for the clotting... 

Among the vitamin K vitamers, only phylloquinone is accounted for routine food analysis. Furthermore infant formulas, both milk-based and soy protein-based, are supplemented with a synthetic preparation of phylloquinone (the only form admitted) [403], which usually contain about 10% of the biologically inactive ctT-isomer [497]. 

Vitamin K is traditionally extracted with solvents such as acetone or ethanol, followed by a sample clean-up, such as enzymatic hydrolysis [498,499], column chromatography [308], TEC [500,501], SPE [502,503], or a combination of them. Gao and Ackman [504] couple two different methods, an SPE purification, previously reported by Eerland and Sadowski [505], preceded by a modified enzymafic digestion from fhe original procedure of Bueno and Villalobos [506]. They observe fhaf SPE step is nol enough to purify the sample. Jacob and Elmadfa [507] report an extraction from food with different solvents (according to the type of food), the evaporation of these and re-dissolving in hexane to perform a simple LEE as the clean-up step using methanol/water. SFE has been successfully applied for phylloquinone extraction from powdered infant formulas [497]. 

Haroon, Y., Shearer, M. J., Rahim, S., Gunn, W. G., Mcenery, G. and Barkhan, P. 1982. The content of phylloquinone (vitamin Kd in human milk, cows milk and infant formula foods determined by high-performance liquid chromatography. J. Nutr. 112, 1105-1117. 

Phylloquinone has been extracted from powdered infant formula using supercritical carbon dioxide at 8000 psi and 60°C for 15 min (65). The extracted material was readily recovered by depressurization of the carbon dioxide across an adsorbent trap and then washed from the trap with a small volume of dichloromethane/acetone (1 + 1) to give a sample suitable for direct HPLC analysis. Trial experiments gave recoveries of 92% of phylloquinone from a Chro-mosorb W matrix. A similar technique was applied to the extraction of retinyl palmitate from cereal products (90). 

The weak adsorption of phylloquinone on silica gel (Table 5) provides the basis for silica purification of lipid extracts of milk and infant formulas in vitamin K assays. Haroon et al. (98) washed the hydrocarbons from a silica gel column with petroleum ether, after which the phylloquinone fraction was eluted with petroleum ether containing 3% diethyl ether lipids that were more polar than phylloquinone were retained on the column. 

Photometric determination of phylloquinone has sufficient sensitivity for the analysis of green leafy vegetables and vitamin K-supplemented infant formulas, but it lacks the required sensitivity for the analysis of foods that contain smaller amounts of the vitamin. 

AOAC official method 992.27. Trans-vitamin K, (phylloquinone) in ready-to-feed milk-based infant formula. Liquid chromatographic method. In MP Bueno, ed. Official Methods of Analysis of AOAC International. 16th ed. Arlington, VA AOAC International, 1995, p. 50-6-50-8. 

Common Name Vitamin K Phytomeanadion Phylloquinone Structural Formula ... 

Vitamin K1 (phylloquinone) exists naturally only in the trans-form. Trans- and cii -isomers are formed during UV light exposure or synthetic production of vitamin Kl. This cw-isomer is considered to have low bioactivity [84]. Therefore, inactive cii-vitamin Kl is necessary to measure individually to evaluate the true nutritional status of fortified foods. The developed method proved to be rapid and sensitive, which allows cis- and trans-vixasam Kl extracted from milk-based, rice-based, and soy-based infant formula to be simultaneously determined by UPLC-MS/MS [83]. 

Vitamin K (phylloquinone), 2, 3 -dihydrophylloquinone, and menaquinones (where n = 4, 5, 6) were extracted fiom milk and infant formula and analyzed on a C,8 column (A = 243 nm, ex 430 nm, em). All compounds were well resolved and eluted in 15 min using a 90/10/0.5 methanol/dichloromethane/methanol (with lOitiM zinc chloride, 5mM sodium acetate, and 5mM acetic acid) mobile phase [344]. Note that this level of salts in the mobile phase could precipitate in various parts of the LC system. Flush the system regularly. The linear working curve extended from 2 to 50 ng/mL with a detection limit of 1.5 ng/mL. The authors noted that this compared favorably to a UV detection limit (at A = 269 nm) of 50 ng/mL. 

Figure 1 Structural formulas of some K vitamers (1) vitamin Ki(20), (VKl), phylloquinone or 2-methyl-3-eicosa-2 -ene-l,4-naphthoquinone (2) trideuterium labeled VKl, VKl-rfj, 2-methyl-rf3-3-eicosa-2 -ene-1,4-naphthoquinone as internal standard for GC-MS analysis (3) VKl-epoxide (4) menaquinone-4, MK4, 2-methyl-3-tetraprenyl-l,4-naph-thoquinone, as an example of the MKn series (5) VKl-heptafluorobutyryl ester after reductive acylation of VKl (6) menadione, vitamin K3 (VK3), or 2-methyl-1,4-naphthoqui-none (7) menadione sodium bisulfite (MSB), water-soluble form of VK3.

HE Indyk, DC Wooflard. Vitamin K in mUk and infant formulas determination and distribution of phylloquinone and menaquinone-4. Analyst 122 465-469, 1997. 

---