Fatty acids/alcohols/waxes

The interpretation of mass spectra of common wax components are described elsewhere (Hamilton, 1995b Evershed, 1992b Christie, 1994). The mass spectra of fatty acids, alcohols, wax esters and other lipids can be found in an open access website (The AOCS Lipid Library, 2011). Briefly, the identification is performed on the basis of the characteristic fragment and molecular ions. For example, the mass spectra of saturated fatty add methyl... 

Lipids are esters of long-chain fatty acids and alcohols or of closely related derivatives. The chief difference between these substances is the type of alcohol in fixed oils and fats, glycerol combines with the fatty acids in waxes, the alcohol has a higher molecular weight, e.g., cetyl alcohols. 

The external cuticle of insects is covered by a waxy layer composed of mixtures of hydro-phobic lipids that include long-chain alkanes, alkenes, wax esters, fatty acids, alcohols, aldehydes, and sterols. The primary purpose of this layer is to maintain water balance and prevent desiccation, as described in Chapter 6, but many of the cuticular lipid components have important secondary roles as intraspecific contact chemical signals (pheromones). These roles include species and sex recognition during reproductive interactions, and nestmate recognition and other colony organization functions in social insects. Thus, these compounds are essential mediators of insect behaviors. Cuticular compounds are also exploited by parasitoids and predators as interspecific contact cues (kairomones) to aid in host location. 

Triterpenoids occur in hardwood parenchyma resin, and closely related sterols are also present in softwoods (Fig. 5-6). Sterols typefied by the abundant /3-sitosterol, mostly have a hydroxyl group in the C-3 position. They also appear as the alcohol component in fatty acid esters (waxes). Triterpenoids and sterols are sparingly soluble substances contributing to pitch problems in pulping and paper making. Some trees contain polyterpenes and their derivatives known as polyprenols. Betulaprenols, present in birch wood, belong to this category of substances (Fig. 5-7). 

Waxes Another type of lipid, waxes, also contain fatty acids. A wax is a lipid that is formed by combining a fatty acid with a long-chain alcohol. The general structure of these soft, solid fats with low melting points is shown below, with x and y representing variable numbers of CH2 groups. 

The exact identity of allelochemics in BPH-resistant varieties is not yet known. However, a large group of low molecular weight compounds, such as essential oils, particularly terpenoids, alcohols, aldehydes, fatty acids, esters, waxes, etc., would be obtained by steam distillation (34, 35). Obata et al. (32) have identified a... 

Lipids are one of the major structural components in living cells and encompass a myriad different types of compound. In most cases, they possess only one common property, which is their solubility in non-polar solvents such as chloroform, ether, hydrocarbons or alcohols and insolubility in water (Davenport and Johnson, 1971). Some of the types of compounds that are classified as lipids include fatty acids, glycerides, waxes, cholesterol esters, phosphoglycerides and sphingolipids. 

The most recommended carriers for the development of particles by spray chilling in food industries are fatty acids, alcohols, triacylglycerols, and waxes (Okuro et al 2013b). For the food... 

Camauba wax (also called Brazil wax or palm wax) is isolated from the leaves of the palm Copernicia prunifera (camauba palm), a plant native to northeastern part of Brazil. It has an appearance of yellow flakes. Camauba consists mostly of aliphatic esters (40.0 wt%), diesters of 4-hydroxycinnamic acid (21.0 wt%), ra-hydroxycarboxylic acids (13.0 wt%), and fatty acid alcohols (12.0 wt%). These compounds are mainly derived from acids and alcohols in the C26-C30 range. Distinctive for camauba wax is the high content of methoxycinnamic acid as well as diesters. This type of wax is one of the hardest natural waxes with the highest melting point between 78°C and 86°C, but most often the melting-point range is 82°C-85°C. Like all other waxes, it is insoluble in water, but soluble on heating in ethyl acetate and in xylene, and practically insoluble in ethyl alcohol (European Pharmacopeia 6.0). 

Figure 2. Gas chromatograms and major ester identifications (combination of fatty acid/alcohol) of (a) male and (b) female Harderian glands during the summer. Column temperature 60°C for 1 min, raised to 240°C at 10°C/min. Each figure above a peak is composed of two numbers. The first indicates the length and saturation of the fatty acid chain, and the second indicates the length and saturation of the alcohol chain of the main wax ester.

Dimethylamino-2-methyl-1-propanol emulsifier, fatty acid soaps waxes 2-Dimethylamino-2-methyl-1-propanol emulsifier, fatty acid systems Lanolin acid emulsifier, fatty alcohol Cetoleth-18... 

The cuticular waxes of insect species may contain the following chemical classes hydrocarbons, fatty acids, alcohols, triacylglycerols and wax esters (Golgbiowski et al., 2011 Nelson Blomquist, 1995). The waxes of some species also contain aldehydes, ketones, esters and sterols. The wax compositions of insects can vary depending on stage, sex, age, and their position in the colony hierarchy. Cuticular waxes can also vary within species as a response to living conditions such as temperature, dryness and available food. The major function of insect waxes is protection against desiccation, but they also prevent microbial infections, affect the adsorption of chemicals and play a role in chemical communication... 

The components of plant cuticular waxes have been reviewed by Kolattukudy (1980). Major components include hydrocarbons, very-long-chain fatty acids, alcohols and monoesters. These and minor components are shown in Table 2.5. 

The wax associated with suberin has also been examined, but only recently. Hydrocarbons, wax esters, very-long-chain fatty acids, alcohols and terpenes have all been found. These are all typical... 

Lipids that are solid at ambient temperatures are referred to as fats while those that are liquid are called oils . Two main groups, having significantly different natural functions and structures, can be classified as the neutral lipids (acylglycerides, fatty acids, alcohols, hydrocarbons, waxes) and polar lipids (glycolipids, phospholipids). Neutral lipids generally form part of an energy store, while polar lipids are functional molecules in the structure of membranes. 

Ratnayake, W.N. and Ackman, R.G. (1979b) Fatty alcohols in capelin, herring and mackerel oils and muscle lipids II. A comparison of fatty acids from wax esters with those of triglycerides. Lipids 14, 804-810. 

Emulsions (contain 5-35% actives) upper temperature limit of fatty acid esters, waxes, fatty alcohols, PEG esters of di-fatty acids, ethanolamides, alkylamides, etc. 

Waxes are important derivatives of higher alcohols. They are higher alcohols esterified with long-chain fatty acids. Plant waxes are usually found on leaves or seeds. Thus, cabbage leaf wax consists of the primary alcohols C12 and C18-C28 esterified with palmitic acid and other acids. The dominant components are stearyl and ceryl alcohol (C26H53OH). In addition to primary alcohols, esters of secondary alcohols, e. g., esters of nonacosane-15-ol, are present ... 

LIPIDS. Fatty materials that are soluble in fat solvents (ether, chloroform, alcohol, etc.). They include fatty acids, fats, waxes, fixed oils, steroids, lecithins, and fat-soluble vitamins (vitamins A, D, and K)... 

Camauba wax (Brazil wax or Cera wax) Wax esters (esters of long-chain fatty alcohols with long-chain fatty acids). The wax esters constitute C46 to C54 molecular species. Fronds of the Copernicia cerifera in Brazil sF c [69]... 

If water is eliminated from the reaction mixture, the equilibrium tends to the right side, and almost all acid or alcohol is transferred to the ester. In context with RR, the following esters should be mentioned - Cellulose esters, - starch esters, - sucrose fatty acid esters, - soibitan esters of fatty acids, - sulfosuccinates, - fatty acid esters, - waxes, fats and oils and all other glycerides, alkyd resins, esters of inorganic acids with fatty alcohols, e.g., fatty alcohol sulfates, fatty alcohol ether sulfates, fatty alcohol phosphates, phtalates, azelates and sebacates (aplastic additives), as well as the esters of - citric acid, - tartaric acid and - lactic acid. 

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