Monounsaturated fatty adds

More than LOO different fatty acids are known, and about 40 occur widely. Palmitic acid (C ) and stearic acid (Cjy) are the most abundant saturated fatty adds oleic and linoleic acids (both Care the most abundant unsaturated ones. Oleic acid is monounsaturated since it has only one double bond, whereas linoleic, linolenic, and arachidonic acids are polyunsaturated fatty acids because they have more than one double bond. Linoleic and linolenic... 

Fatty acids of plant, animal, and microbial origin usually consist of an even number of carbon atoms in the straight chain. The number of carbon atoms of fatty adds in animals may vary from 2 to 36, whereas some microorganisms may contain 80 or more carbon atoms. Also, fatty adds of animal origin may have one to six ds double bonds, whereas those of higher plants rarely have more than three double bonds. Fatty adds also may be saturated, monounsaturated (monoenoic), or polyunsaturated (polyenoic) in nature. Some fatty acids may consist of branched chains, or they may have an oxygenated or cyclic structure. 

FIGURE 17-9 Oxidation of a monounsaturated fatty add. Oleic acid, asoleoyl-CoA (A9), is the example used here. Oxidation requires an additional enzyme, enoyl-CoA isomerase, to reposition the double bond, converting the cis isomer to a trans isomer, a normal intermediate in 13 oxidation. 

Dietary FUFAs decrease Ihc plasma LDL-cholesierol level. Vegetable oils contain high levels of PUFAs such a linoleic add (18 2), which constitutes about 25, 50, 63, and 75% of the fatty adds in peanut, soy, sunflower, and safflower oils, respectively. The quantity of 18 2 in beef and pork fat is only 5-10% and is under 3% in tropical oils. PUFAs produce decreases in LDL-cholestcrol, possibly by the same (unknown) mechanism as monounsaturates. The question of whether dietary FUFAs have a greater or similar effect on LDL-cholesterol remains unsettled. 

What about the choices betw een carbohydrates, mono unsaturated fatty acids, and FUFAs Studies on monounsahirated fatty adds versus carbohydrates have shown that monounsaturated fatty acids provois a decrease in plasma TGs and an increase in HDL[Pg.366]

Oleic acid (18 1 tjj9), a monounsaturated fatty acid, is the major fatty add in human milk. Oleic acid, as well as the products resulting from its further desaturation and elongation, are called the omegit-9 fatty adds. The omega-9 fatty acid 24 l(u9 is a major fatty acid in the membranes of nerves. The omega-9 fatty add 20 3to9 is called the Mead acid. Mead acid accumulates in the body in response to a defi-... 

FIGURE 635 Conversion of stearic add to an 18 1 fatty add. Through formation of a double bond, stearic acid (18 0), a saturate, is converted to add (18 1), a monounsaturate. 

No explicit mention is made of the effect of trans-fatty adds or hydrogenated vegetable oils, nor of monounsaturated vegetable oils such as olive oil, as per the Mediterranean diet.)... 

Abbreviations a-BFAs anteiso-branched fatty acids AGP acyl carrier protein BHLH active soluble domain of SREBP CNS central nervous system DSD delta 5 desaturase D6D delta 6 desaturase ER endoplasmic reticulum Hik histidine kinase HUFA highly unsaturated fatty acid LXR liver X receptor MUFA monounsaturated fatty add NF-Y nuclear factor Y PLs phospholipids PP peroxisome proliferator PPAR PP-activated receptor PPRE PP response element PUFA polyunsaturated fatty acid PUFA-BP PUFA binding protein PUFA-RE PUFA response element RXR retinoid X receptor SCAP SREBP cleavage-activating protein SCD steraroyl CoA desaturase SFA saturated fatty acid SRE sterol response... 

In a similar study using differential thermal analysis (DTA), the perturbation effects of fatty acids on the SC were studied (Tanojo et al., 1994). Thermal behavior of the SC revealed that saturated fatty adds easily mix with the skin lipids and monounsaturated fatty acids to form a separate domain containing mostly pure fatty acids within the SC lipids. Polyunsaturated fatty acids also formed separate domains, but the extent of thermal transition was more than that showed by saturated fatty acids and less than monounsaturated fatty acids. In a recent investigation, SEMs of the skin treated with 10% oleic acid in ethanolic solution showed generation of pores on the surface of epidermal comeocytes (Touitou et al., 2002). 

Table 10.9 and Table 10.10 summarize the effects of various PUFA on gene expression. In the case of enzymes involved in carbohydrate and lipid metabohsm, both omega-3 and omega-6 fatty aeids appear to suppress the genes that eneode for several enzymes (Table 10.9), whereas saturated, trans-, and monounsaturated fatty acids fail to suppress. DHA appears more potent in its effect than other PUFA. Omega-6 and omega-3 fatty acids and monounsaturated fatty adds induce acyl-CoA oxidase, the enzyme involved in beta-oxidation, but here again, DHA appears to be more potent. 

Tree nuts are highly nutritious and provide macronutrients (fat, protein, and carbohydrate)[l,8], micronutrients (minerals and vitamins)[l], fat-soluble bioactives (monounsaturated fatty adds [MUFA], polyunsaturated fatty acids [PUFA], monoacylglycerols [MAG], diacylglycerols [DAG], tria-cylglycerols [TAG], phospholipids, sterol esters, tocopherols, tocotrienols, phytosterols, phytostanols, squalene, terpenoids, sphingolipids, and essential oils, among others) [1,4-6,9-12] (Table 1.2), and phy-... 

Note Percentage of recommended dietary allowances (RDA) is based on a 2000 kcal diet SFA, saturated fatty acids MUFA, monounsaturaled fatty acids PUFA, polyunsaturated fatty adds. 

SFA-Saturated fatty acids (capric acid, caprylic acid, myristic add, lauric acid, palmitic acid, stearic acid). Note MUFA, monounsaturated fatty acids PUFA, poly unsaturated fatty adds. 

The monounsaturated fatty add ester (3/il) is mixed with peracetic add (150/il) and allowed to stand for 2—3 h at room temperature. For dienes, twice the amount of peracetic add and at least twice the reaction time are needed. Samples may be analysed directly or neutralized with soldium bicarbonate and extracted with hexane for subsequent GC analysis [108,109. ... 

The increase in the saturated fatty acids (myristic and palmitic) found in lean and myristic acid in subcutaneous fat are very likely due to the inhibition of stearoyl-CoA desaturase activity, a key enzyme involved in the synthesis of monounsaturated fatty acids (MUFA) by CLA. Studies by Lee el al. (22) and Bretillon el al. (23) demonstrated that CLA isomers inhibited A9 desaturase activity, and thus this inhibition caused an inaease in the saturated fatty add content. Changes in the unsaturated fatty acid profile of subcutaneous fat could result from the increase of 18 1 and 18 2 due to the contribution of CLA 60 in the diet. CLA 60 was substituted for com in the study by Thiel-Cooper el al. (3) therefore, because CLA 60 contains high concentrations of unsaturated fatty acids, the diet would be higher in unsaturated fatty acids than a com diet alone, hi earlier work, Banni el al. (24) and Sdbedio el al. (25) suggested that... 

The lipid composition of adipose tissue in NMRI and NMRI nu/nu mice has been measured by NMR. A voxel size of 1.5 mm x 1.5 mm x 1.5 mm was used to collect spectra without water suppression. The relative amounts of saturated, monounsaturated, and polyunsaturated fatty acids were measured after correction for T2 relaxation in intra-abdominal white adipose tissue and brown adipose tissue deposits. The composition of brown adipose tissue in NMRI mice was significantly different from brown adipose tissue in NMRI nu/nu mice except for the fraction of monounsaturated fatty adds. However, in white adipose tissue only the fraction of monounsaturated fatty acids was significantly different between NMRI and NMRI nu/nu mice. Brown adipose tissue and white adipose tissue of NMRI mice differed in the amount of saturated and diunsaturated fatty acids. 

Figure 1 Fatty-acid structure and nomenclature. (A) Chemical formula and carbon atom numbering system for a 16-carbon saturated fatty acid (16 0). (B) Schematic representation of 16 0. (C) A monounsaturated fatty add, 18 1n-9, showing the double bond nine carbon atoms from the methyl end (carbon 18). (D) The essential n-6 fatty acid 18 2n-6, where the first double bond is found six carbon atoms from the methyl end. The two double bonds are separated by a methylene (-CH2-) group. (E) The essential n-3 fatty acid 18 3n-3, where the first double bond is found three carbon atoms from the methyl end. (F) Phytanic acid, a dietary / -methyl-branched-chain fatty acid (3,7,11,15-tetramethyl 16 0). The melhyl group on carbon 3 prevents this fatty acid from degradation by /3-oxidation. (G) Pristanic acid (2,6,10,14-tetramethyl 15 0) is the product of phytanic acid o-oxidation, in which a single carbon (carbon 1) is lost. The methyl group on carbon 2 does not preclude subsequent degradation by /3-oxidation.

LA, linoleic acid ALA, ct-linolenic acid AA, arachidonic acid DHA, docosahexaenoic acid ERA, eicosapentaenoic acid TRANS-FA, frans-fatty adds SAT, saturated fatty acids MONOs, monounsaturated fatty acids. 

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