Diol lipid

6 Diol Lipids, Higher Alcohols, Waxes and Cutin 

The diol lipids which occur in both plant and animal tissues are minor lipid constituents. The diol content is about 1% of the content of glycerol. Exceptions are sea stars, sea urchins and 

In a glycodiol lipid one hydroxyl group of ethylenediol is esterified with a fatty acid. 

Diol lipids with structures analogous to phosphatidyl choline or plasmalogen have also been identified. 

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Diol lipids have been reported only recently when techniques for their stmcture elucidation were developed. Small quantities of diol lipids, such as diacylpropane-l,3-diol, diesters of butane-1,3-diol, and butane-1,4-diol are found in mammalian and fish liver, mammalian adipose tissues, egg yolk, com seed, and yeast (20). From Actynomyces olivaceus, mixed acyl- and alk-l-enyl derivatives of simple diols have been isolated (21). An acylated diol phospholipid has been produced by the yeast Lypomyces starkeyi when grown on propane-1,2-diol (22). 

Suzuki T, Hasegawa K. Diol lipids in the phospholipid fraction of Lipomyces starkeyi grown in the medium containing 1,2-propanediol. Agric. Biol. Chem. 1974 38 613-620. 

Only recently has the presence of diol lipids, such as diacyl propane-1,3-diol, been confirmed for a wide variety of tissues. This is probably because techniques for the elucidation of their structures are a recent development. Small quantities of such diols are found... 

It has been discovered only in recent years that esters of various short-chain diols occur in nature as well as the esters of glycerol. The discovery, isolation and characterisation of these diol lipids was rendered possible by the application of modem chromatographic methods. 

Diol lipids have recently been detected in maize oil (seed oil from Zea mays) with the help of chromatographic methods [12]. It was evident that adsorption TLC was not capable of separating the esters and alkenyl ether esters of diols from the corresponding glycerol derivatives [12] (see also [22] and [9]). Using TLC, it was nevertheless possible to fractionate the products of alkaline methanolysis of the triglycerides of maize oil into three fractions methyl esters, alkenyl ethers and polyhydric alcohols. The alcohols could be separated and identified as their acetates by gas chromatography [12]. 

Triglycerides and esters of diols (diol lipids), compounds which cannot be separated by adsorption TLC, can be fractionated into classes through reversed phase partition TLC this applies equally to the corresponding alkoxylipids [9]. Chromatography on hydrophobic layers is also suitable for separating the aldehydic cores which are obtained from unsaturated lecithins by reductive ozonolysis [168] (see Fig. 147, p. 409) and for analysing sphingosine bases [129]. 

Very recently, a Japanese team reported an elegant example of molecular recognition of vesicles. It was shown by agglutination assays that vesicles equipped with boronic acid specifically bind to vesicles containing diol lipid such as phosphatidylinositol. It was demonstrated that the interaction of boronic acid vesicles and inositol vesicles is the result of selective coordination of the boronic acid and the carbohydrate diol. 

Diol lipids Fatty acid, ethane, propane, or butane diol... 

Bergelson, L.D. Diol lipids. New types of naturally occurring lipid substances. Fette Seifen Anstrichm. 75, 89 (1973)... 

Cyano, amino, and diol residues are the most common fimctional groups in the hydophilically modified thin layers and not very commonly used for PTLC in lipids. 

A.P. Tulloch, Beeswax structure of the esters and their component hydroxy acids and diols, Chemistry and Physics of Lipids, 6, 235 265 (1971). 

Arene oxides and diol epoxides are generally unstable in aqueous, especially acidic media (103-105). and in addition, several groups have noted that DNA has a marked catalytic effect upon diol epoxide hydrolysis (106.107). However, in cells there appears to be sites, probably lipid in nature, in which these compounds can have much longer half-lives. 

The lipids used in the syntheses of neoglycolipids are often commercially available most of the long-chain carboxylic acids, n-alcanols, n-alcanethiols or -alkylamines are readily available as well as a,o)-dicarboxylic acids, diols or diamines useful for the syntheses of bola-amphiphiles. 

Racemic thioglycerol (3-sulfanylpropane-l,2-diol) was used for the attachment of two lipid chains via ester bond formation with the hydroxy groups 82 while the free thiol group serves for selective cross-linking to other molecules via disulfide or sulfide bonds utilizing mild thiol-disulfide interchange or thiol addition reactions (Scheme 15).[163,164,167]... 

The synthesis of (65,7S,9i ,10i )-6,9-epoxy-nonadec-18-ene-7,10-diol 28, a marine epoxy lipid isolated from the brown algae Notheia anomala, by an oxiranyl anion strategy, was reported. One main step is the constmction of the furan ring <99TL731>. 

The mycobacterial cell wall, discussed in Chapter 8, contains mycolic acids bound covalently at the nonreducing ends of arabinogalac-tans that are attached to the inner peptidoglycan layer,e as well as phosphatidylinositol-anchored lipoarabinomannans. Other unusual lipids that are also present and account for some of the difficulty of treatment with antibiotics include esters of mycocerosic acid with long-chain diols known as phenolphthiocerols and phthiocerols.f/fg... 

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