Medium chain

Ziegler process) and telomerization of alkenes to medium chain derivatives for detergents and fats. Both processes operate by insertion of an alkene into AIR bonds. 

A USDA report indicates that between 1967 and 1988, butter consumption remained stable at 2 kg per capita, margarine dropped from 5.1 to 4.7 kg, and measured total fat intake per day dropped from 84.6 to 73.3 g (14). This study also projects that the reduced consumption of tropical oils is only temporary and will return to former use levels, possibly even higher. One reason for this projected rise in tropical oil consumption is the knowledge of the beneficial effects of medium-chain length acids high in lauric oils. There is a keen interest in omega-3 fatty acids, as well as linoleic acid, contained in fish oils. 

Fats and oils may be synthesized in enantiomerically pure forms in the laboratory (30) or derived from vegetable sources (mainly from nuts, beans, and seeds), animal depot fats, fish, or marine mammals. Oils obtained from other sources differ markedly in their fatty acid distribution. Table 2 shows compositions for a wide variety of oils. One variation in composition is the chain length of the fatty acid. Butterfat, for example, has a fairly high concentration of short- and medium-chain saturated fatty acids. Oils derived from cuphea are also a rich source of capric acid which is considered to be medium in chain length (32). Palm kernel and coconut oils are known as lauric oils because of their high content of C-12 saturated fatty acid (lauric acid). Rapeseed oil, on the other hand, has a fairly high concentration of long-chain (C-20 and C-22) fatty acids. 

Fat. Milk fat is a mixture of triglycerides and diglycerides (see Fats and fatty oils). The triglycerides are short-chain, C. —C., medium-chain, 24 46 ... 

Essential oils are obtained from fmits and flowers (61,62). Volatile esters of short- and medium-chain carboxyHc acids or aromatic carboxyHc acids with short- and medium-chain alcohols are primary constituents of essential oils, eg, ethyl acetate in wines, brandy, and in fmits such as pineapple ben2yl acetate in jasmine and gardenia methyl saHcylate in oils of wintergreen and sweet birch. Most of these naturally occurring esters in essential oils have pleasant odors, and either they or their synthetic counterparts are used in the confectionery, beverage, perfume, cosmetic, and soap industries (see Oils, essential). 

FIGURE 24.13 The subunit structure of medium chain acyl-CoA dehydrogenase from pig liver mitochondria. Note the location of the bound FAD (red). (Adapted from Kim, J-T., and Wiz, J., 1988. Structure of the medium-chain acyl-CoA clchyclro-genase from pig liver mitochonciria at 3-A resolution. Proceedings of the National Academy of Sciences, USA 85 6671-668. )... 

Not all ionic liquids are the same, different combinations of anions and cations produce solvents with different polarities. No ionic liquids have shown themselves to be super-polar regardless of the method used to assess their polarities, ionic liquids come within the range of molecular solvents. Most general measures of overall polarity place ionic liquids in the range of the short- to medium-chain alcohols. 

GOR40 Medium chain fatty acids Insulin regulation... 

In vitro and ex vivo studies have shown that FATPs transport LCFAs and very long-chain fatty acids (VLCFAs) but no medium-chain fatty acids, fatty acid esters, or lipid-soluble vitamins [4]. LCFA transport is inhibited by prior protease treatment. Synthetic substrates for FATPs include 14C-labeled fatty acids and the fluorescently labeled fatty acid analogue C1 -BODEP Y-Cl 2. Using the latter substrate, differences in fatty acid uptake kinetics between FATP expressing 3T3 LI adipocytes and 3T3 LI fibroblasts, which are devoid of FATPs, can be readily appreciated (Fig. 2). 

Figure 3. Mitochondrial fatty acid oxidation. Long-chain fatty acids are converted to their CoA-esters as described in the text, and their fatty-acyl-groups transferred to CoA in the matrix by the concerted action of CPT 1, the acylcarnitine/carnitine exchange carrier and CPT (A) as described in the text. Medium-chain and short-chain fatty acids (Cg or less) diffuse directly into the matrix where they are converted to their acyl-CoA esters by a acyl-CoA synthase. The mechanism of p-oxidation is shown below (B). Each cycle of P-oxidation removes -CH2-CH2- as an acetyl unit until the fatty acids are completely converted to acetyl-CoA. The enzymes catalyzing each stage of P-oxidation have different but overlapping specificities. In muscle mitochondria, most acetyl-CoA is oxidized to CO2 and H2O by the citrate cycle (Figure 4) some is converted to acylcamitine by carnitine acetyltransferase (associated with the inner face of the inner membrane) and exported from the matrix. Some acetyl-CoA (if in excess) is hydrolyzed to acetate and CoASH by acetyl-CoA hydrolase in the matrix. Enzymes ...

Enzymes 7,9, and 13 form a trifunctional protein associated with the inner face of the inner mitochondrial membrane. Very-long-chain acyl-CoA dehydrogenase is also associated with other inner mitochondrial membranes while the other enzymes are in the matrix and may be loosely associated with the inner face of the inner membrane. A medium-chain 2-enoyl-CoA hydratase may also be present in the mitochondrial matrix. 

Takagi, Y., Yasuda, R., Yamaoka, M. and Yamane, T. 2004. Morphologies and mechanical properties of polylactide blends with medium chain length poly(3-hydroxyalkanoate) and chemically modified poly(3-hydroxyalkanoate). Journal of Applied Polymer Science 93 2363-2369. 

Timm, A., Steinbuchel, A. 1990. Formation of polyesters consisting of medium-chain-... 

The influence of the lipophilic external phase on the production of xylan-based microparticles by interfacial cross-linking polymerization has been investigated (Nagashima et al., 2008). Three different external phases were investigated a 1 4 (v/v) chloroform cyclohexane mixture, soybean oil, and a medium chain triglyceride, with viscosities below 1, 24, and 52 cP, respectively. It was observed that the use of these different lipid phases results in different macroscopic and microscopic aspects of the system (Figure 10). 

Lycopene was dispersed in medium-chain triglyceride oil derived from esterification of fatty acids and glycerol composition was stable for 3 mo at 25°C, compared with dispersion on soybean oil... 

The application of microemulsions in foods is limited by the types of surfactants used to facilitate microemulsion formation. Many surfactants are not permitted in foods or only at low levels. The solubilization of long-chain triglycerides (LCTs) such as edible oils is more difficult to achieve than the solubilization of short- or medium-chain triglycerides, a reason why few publications on microemulsions are available, especially because food-grade additives are not allowed to contain short-chain alcohols (C3-C5). 

Hajjaj, H. et al.. The biosynthetic pathway of citrinin in the filamentous fungi Monascus ruber as revealed by C-NMR, Appl. Env. Microbiol, 65, 311, 1999. Hajjaj, H. et al.. Medium-chain fatty acids affect citrinin production in the filamentous fungus Monascus ruber, Appl. Env. Microbiol, 66, 1120, 2000. 

Kurata A, T Kurihara, H Kamachi, N Esaki (2005) 2-haloacrylate reductase a novel enzyme of the medium-chain dehydrogenase/reductase superfamily that catalyzes the reduction of carbon-carbon double bond of unsaturated organohalogen compounds. J Biol Chem 280 20286-20291. 

H. Muller, C. P. Herold, S. von Tapavicza, M. Neuss, W. Zollner, and F. Burbach. Esters of medium chain length carboxylic acids as oil-phase components in invert drilling muds (Ester von Car-bonsauren mittlerer Kettenl ge als Bestandteil der Olphase in Invert-Bohrspiilschlammen). Patent EP 386636, 1990. 

Pancreatic enzyme supplements should be taken immediately prior to meals to aid in the digestion and absorption of food. Alternately, patients can supplement their diet with medium chain triglycerides (MCTs) or ingest foods rich in MCTs since they do not require pancreatic enzymes for absorption. An appropriate regimen incorporates the successful doses of each enzyme (amylase, lipase, and protease) from the starting non-enteric-coated regimen. As with the previous example, a patient stabilized on Viokase-8, six tablets with each meal, can be transitioned to Pancrease MT-16 three tablets with meals. The famotidine can then be discontinued. 

Cl, critical illness HS, high stress PD, pulmonary disease TR, trauma EPA, eicosapentenoic acid CLA, y-linolenic acid MCT, medium chain triglycerides... 

Water-immiscible, volatile, or more likely nonvolatile liquids such as vegetable oils, aromatic and aliphatic hydrocarbons (mineral oil), medium-chain triglycerides, and acetylated glycerides. 

K Morimoto, T Nakamura, K Morisaka. (1989). Effect of medium-chain fatty acid salts on penetration of a hydrophilic compound and a macromolecular compound across rabbit corneas. Arch Int Pharmacodyn 302 18-26. 

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