Fat-soluble compounds

Properties of Latia luciferin. Latia luciferin is a highly hydrophobic, fat-soluble compound, and volatile under vacuum. It is a colorless liquid, with an absorption maximum at 207nm (s approx. 13,700 Fig. 6.1.2). The chemical structure of Latia luciferin has been determined to be 1 (C15H24O2), an enol formate of a terpene aldehyde 3 (Fig. 6.1.3 Shimomura and Johnson, 1968b). The enol formate group of Latia luciferin is unstable the luciferin is spontaneously hydrolyzed... 

Sodium benzoate is used as a broad-spectrum antimicrobial, inhibiting bacteria, molds, and yeasts. The high acid content of the soft drink is necessary for the preservative action. Sodium citrate buffers the acids, so the pH stays low (acidic). It also emulsifies any fats or fat-soluble compounds in the flavorings, keeping them in solution. 

Vitamin D is the name given to a group of fat-soluble compounds essential for maintaining the mineral balance of the body. Vitamin D is also known as... 

This approach can be used only for fat-soluble compounds that follow the same lymphatic route to be transported to the liver as carotenoids. The bioavailability of the compound of interest is determined by monitoring the appearance of the compound and its newly formed intestinal metabolites in the postprandial chylomicron fraction of plasma [also called the density < 1.006 kg/L fraction or triglyceride-rich lipoprotein (TRL) fraction because it is generally a mixture of chylomicrons (CMs) and very low density lipoproteins (VLDLs)] as a function of the time after ingestion. 

Competition between Carotenoids and Other Fat-Soluble Compounds.385... 

The reaction of peroxidase (metmyoglobin) with hydrogen peroxide leads to the generation of a green-blue radical from a colorless compound 2,2 -azino-(u s(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). It is slowed down in the presence of an antioxidant, an effect that is used for its quantitation in the Total Antioxidant Status Kit (manufacturer Randox, UK) [10]. Problems associated with this method are due to potential interference of the reaction compound H202 with components of the sample to be investigated. No investigation of fat-soluble compounds is possible. 

The nutritional experiments with carotene and fish oils led to the conclusion that a second fat-soluble compound was essential for normal rat growth. Rickets, the condition caused by vitamin D deficiency, is a disease afflicting children where, because of impaired calcification, bone formation is disturbed and the bones become bowed and otherwise deformed. In adults, especially multiparous women, vitamin D deficiency produced osteomalacia—demineralization of bone, leading to tenderness over the bones, pain, and muscle weakness. Rickets was particularly prevalent in slum areas. Glasgow, Vienna, and Lahore were notorious for the high incidence of the disease. 

Another area of concern is exposure to fat-soluble compounds such as PCBs or chlorinated pesticides. All cells contain lipids or fat the high number of densely packed cells of the brain means that the brain is just a big ball of fat. The brain is a great storage site for fat-soluble compounds that can cross the blood-brain barrier. An additional concern is that these compounds can be mobilized from the fat of women breastfeeding their infants, resulting in exposure to the infant and, given the size of the infant, this exposure translates into a large dose. 

Basically all fat-soluble compounds of the diet are absorbed and partially metabolized in the upper part of the small intestine. Afterwards, they are transported to their target organs via the systemic circulation. Therefore, it is impossible to deliver p-carotene to the lower parts of the intestine via the chymus. p-Carotene reaches this part of the intestines only after systemic absorption. 

Yet when p-carotene is coated with pectin (edible coating), the pectin prevents p-carotene — or other carotenoids as well as fat-soluble compounds — from being absorbed in the upper parts of the small intestine. As a consequence, these coated compoimds can be transported via the chymus to the colon, where the pectin is broken down to short-chain fatty acids by bacteria. These fatty acids play an important role as growth regulators of the colonic mucosa cells. At the same time, the active agents, such as p-carotene, are released and can then be absorbed by the mucosa. 

Vitamin D is a group of fat-soluble compounds and the main forms are vitamin D3 (cholecal-ciferol) (Figure 19.14), which is the physiological form and the synthetic analogue vitamin D2 (ergocalciferol). They only differ by the side chain of the sterol skeleton. 

The mixed micelles contain predominantly FFAs, 2-monoacylglycerols, and unesterified cholesterol in addition to other fat-soluble compounds, such as the fat-soluble vitamins A, D, E, and K. 

It is important to purify proanthocyanidins, particularly for determining their conversion yield. It is also advantageous to do so to eliminate extraneous material that might otherwise react with the proanthocyanidins. A combination of liquid-liquid extraction and adsorption chromatography is effective in removing impurities. The use of chloroform in liquid-liquid extraction is very effective in removing fat-soluble compounds such as carotenoids, chlorophyll, oils, and waxes. These compounds would be expected in leafy plant tissues (carotenoids and chlorophyll) as well as seeds and fruits (oils and waxes). Ethyl acetate is effective in the selective removal of flavan-3-ol monomers, which are also typically present with proanthocyanidins. 

The first grouping is a mix of fat-soluble compounds that function as hormones, co-factors, and membrane components. Fat-soluble vitamins separate on a Cis column in 80% acetonitrile/water and are usually detected at UV, 280 nm, or with fluorescence. Triglycerides are slightly less nonpolar than fat-soluble vitamins and require 60% acetonitrile/water to run on Ci8. They have poor extinction coefficients, and detection at UV, 220 nm, competes with refractive index detection in sensitivity. A phenyl column run in 50%... 

Vitamin A A fat-soluble compound found in fish-liver oils, milk, green and yellow vegetables, and egg yolk. It is required for cell growth and development, epithelial tissue growth and protection, and normal vision. 

Vitamin D A fat-soluble compound found in milk and fish-liver oils that is required for tooth and bone growth. 

Vitamin A is an essential fat-soluble compound acquired from the diet. The parent form of vitamin A is all-iram-retinol. Vitamin A is needed to maintain normal vision, normal reproduction (including spermatogenesis, conception, and placenta formation), and normal cell differentiation (including bone remodeling, maintenance of differentiated epithelial linings and skin, em-... 

Vitamin K — Fat-soluble vitamin K is a group name for fat-soluble compounds which have in common a methylated naphthoquinone ring structure. Vitamin K is found in nature in two forms - Ki or phylloquinone is found in plants and vitamin K2 or menaquinone can be synthesized by many bacteria. Vitamin K3 (menadione) is a synthetic form of this vitamin. Vitamin K is used... 

Fat portion of meats, particularly their phospholipid components, undergo autoxidation/degradation (2) and produce an overwhelming number of volatiles. Fats also serve as a depot of fat-soluble compounds that volatilize on heating and strongly affect flavor. Since compositional characteristics of lipids in meats, vary from one species to another, these factors may be responsible for the development of some species-specific flavor notes in cooked meats (8.9 ). Obviously presence of 4-methyloctanoic and 4-... 

Liposomes are hollow fat particles composed of a closed lipid bilayer. Due to their unique structure, allowing transport of both water-soluble and fat-soluble compounds, and the fact that they may be easily prepared from completely biocompatible materials, liposomes have come into widespread use as vehicles for drug delivery. 

The term Vitamin E was introduced by Evans and Bishop to describe a dietary factor important for reproduction in rats [1]. Natural vitamin E includes two groups of closely related fat-soluble compounds, the tocopherols and tocotrienols, each with the four a-, y-,... 

Bile salts act as "detergents" in nature to maintain insoluble (fat-soluble) compounds in water solution. The bile salts form mixed micelles that consist of amphipathic bile salt molecules surrounding the lipophilic (fal-soJublc) molecules. The hydrophilic ends of the amphipathic molecules face outward, forming a lipophilic environment in the interior of the micelle. Bile salt molecules contain acid groups, such as carboxyl and sulfonyl groups, that usually are ionized under physiological conditions. 

A natural product, cholesterol is a fat-soluble compound that is present in our daily diet. It can form esters with fatty acids. Most of the cholesterol found in the plasma is in the form of cholesterol esters. It can also be endogenously formed in the cells of the body. The majority of the cholesterol is produced by the liver cells however, all other cells also form cholesterol. The membrane structure of the cells is partially made up of cholesterol. It is synthesized from multiple molecules of acetyl-CoA. The major use of... 

About 80% of the cholesterol synthesized in the liver is converted into bile salts. The remainder of the cholesterol, triacylglycerols, other lipids, and hydrophobic substances (including xenobiotics) are transported to other tissues throughout the body by plasma lipoproteins. These lipoproteins, which are classified according to density, consist of apoproteins (also made by the liver) and various combinations of fat and fat-soluble compounds. The liver also stores vitamins, especially vitamin A but also vitamins D, E and K, as well as vitamin B12, in fatstoring Ito cells, located between endothelial cells and hepatocytes. 

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