Plant lipid

Solutions in contact with polyvinyl chloride can become contaminated with trace amounts of lead, titanium, tin, zinc, iron, magnesium or cadmium from additives used in the manufacture and moulding of PVC. V-Phenyl-2-naphthylamine is a contaminant of solvents and biological materials that have been in contact with black rubber or neoprene (in which it is used as an antioxidant). Although it was only an artefact of the separation procedure it has been isolated as an apparent component of vitamin K preparations, extracts of plant lipids, algae, livers, butter, eye tissue and kidney tissue [Brown Chem Br 3 524 1967]. 

A mechanism Is proposed by which water-insoluble plant lipids (sterols etc.) may act as allelochemicals via micelle formation with long-chain fatty acids. By this process plant lipid solubility and transport In the aqueous medium are enhanced. This might suggest a reevaluation of water-insoluble plant constituents such as sterols as potential allelopathic agents. 

Possible Mechanism of Allelopathlc Action of Water-Insoluble Plant Lipids. Many non-polar natural products with germination and growth regulation activities In laboratory tests are In pure form not sufficiently water soluble to account for their allelopathlc activities observed In the field. For this reason the notion exists that sterols and other non-polar plant constituents are not likely to play a role In allelopathlc actions, and It Is generally concluded that the bioactivity data observed In the laboratory are therefore coincidental. 

The Occurrence of Octadeca-trans-11-trans-13-dien-9-ynoic Acid in Plant Lipids. Austr. J. Chem. 13, 488 (I960). 

Murphy D.J. (ed.) (2000) Plant Lipids Biology, Utilization and Manipulation, CRC Press, Boca Raton, FL. 

Kolattukudy PE, Ettinger WF, Sebastian J (1987) Cuticular lipids in plant-microbe interactions. In Stumpf PK, Mudd BD, Ness WD (eds) The metabolism, structure, and function of plant lipids. Plenum Publishing, New York, p 473... 

Animal and dairy fats can be differentiated from plant lipids on the basis of the FA distribution animal fats generally contain less palmitic acid than stearic acid, while palmitic acid predominates over stearic acid in plant oils. 

Plant lipids generally have an even number of carbon FAs, while animal lipids include odd-numbered carbon chain FAs, and, in some cases, branched chain FAs formed by bacterial activity in the digestive tract of ruminant mammals [5,41]. Branched FAs can also be formed in low amounts from other kind of lipids as a result of microbial activity after burial. 

Sterols are seldom detected in archaeological residues due to their low concentration and the tendency to undergo chemical degradation. In any case, the presence of sterols or of their oxidation products in a sample can help distinguish between animal and plant lipid materials cholesterol is the most abundant animal sterol, while campesterol and sitosterol are the two major plant ones. 

THRELFALL, D.R., WHITEHEAD, I.M., Redirection of terpenoid biosynthesis in elicitor-treated plant cell suspension cultures. In Plant Lipid Biochemistry (P.J. Quinn and J.L. Harwood, eds,), Portland Press, London. 1990, pp. 344-346. 

Lipid transfer peptides and proteins occur in eukaryotic and prokaryotic cells. In vitro they possess the ability to transfer phospholipids between lipid membranes. Plant lipid transfer peptides are unspecific in their substrate selectivity. They bind phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, and glycolipids. Some of these peptides have shown antifungal activity in vitro The sequences of lipid transfer proteins and peptides contain 91-95 amino acids, are basic, and have eight cysteine residues forming four disulfide bonds. They do not contain tryptophan residues. About 40% of the sequence adopts a helical structure with helices linked via disulfide bonds. The tertiary structure comprises four a-helices. The three-dimensional structure of a lipid transfer peptide from H. vulgare in complex with palmitate has been solved by NMR. In this structure the fatty acid is caged in a hydrophobic cavity formed by the helices. 

Stumpf, P. K. Shimakata, T. In Biosynthesis and Function of Plant Lipids Proc 6 University of California Amer. Soc. PI. Physiologists Maryland, 1983 1-27. 

Various plant lipid constituents contain cresols (Fiege and Bayer 1987). Runoff from terrestrial sources may contribute cresols to surface waters in addition to endogenous sources such as aquatic plants, animals, and microbes. 

As discussed above, cresols are widely distributed natural compounds. They are formed as metabolites of microbial activity and are excreted in the urine of mammals. Various plant lipid constituents, including many oils, contain cresols. Cresols have also been detected in certain foods and beverages such as tomatoes, tomato ketchup, cooked asparagus, various cheeses, butter, oil, red wine, distilled spirits, raw and roasted coffee, black tea, smoked foods, tobacco, and tobacco smoke (Fiege and Bayer 1987). However, very few monitoring data for cresols in food were found in the literature. 

ThrelfaU DR, Whitehead IM (1990) Redirection of terpenoid biosynthesis in eUcitor-treated plant cell suspension cultines. In Qninn PJ, Harwood JL (eds) Plant lipid biochemistry. Portland Press, London, p 344... 

H. E. Hopp, P. A. Romero, G. R, Daleo, and R. Pont Lezica, in L.-A. Applequist and C. Liljenberg (Eds.), Advances in the Biochemistry and Physiology of Plant Lipids, Elsevier/North-Holland Biomedical Press, Amsterdam, 1979, pp. 313-318. 

Lipoxygenases catalyze oxidation of polyunsaturated fatty acids in plant lipids. Within animal tissues the lipoxygenase-catalyzed reaction of arachidonic acid with 02 is the first step in formation of Ieukotrienes and other mediators of inflammation. These reactions are discussed in Chapter 21. 

Marine lipids with their diversity of unsaturated and branched chain acid moieties are a difficult class of materials to analyze. Ruminants (sheep, goats, cows, etc.) have a bacterial "factory" in the rumen which is able to produce branched-chain partially-hydrogenated lipids from ingested plant lipids. These lipids are incorporated into the milk and meat of the animals and eventually into animals which feed upon the ruminants. As a rule animal lipids are highly complex in comparison to plant materials. Although the branched chain materials are usually present in low concentration when compared to the common fatty acid moieties, complete description of these fats requires more sophisticated GC and thus long open tubular columns in tandem with mass spectrometry and computer analysis of the data has become an important approach. Even with a 100-m column, subcutaneous lipids of barley-fed lambs were so complex that prior fractionation with urea adducts was necessary (17). 

Finally, details of the synthesis of heteropolysaccharides in plants are as yet completely unknown. The structural similarities among some plant gums and such bacterial exopolysaccharides as xanthan gum suggest that similar mechanisms may be operative in bacteria and in plants. Lipid intermediates could be suggested as potential glycosyl donors in the formation of plant gums and mucilages. 

Shorland, F. B., The Distribution of Fatty Acids in Plant Lipids, in... 

RA Moreau, PT Asmann, HA Norman. Analysis of major classes of plant lipids by high performance liquid chromatography with flame ionization detection. Phytochemistry 29 2461-2466, 1990. 

C. Hitchcock and B. W. Nichols, Plant Lipid Biochemistry, Academic Press, New York, 1971. 

For example, the LIFDI mass spectrum of biodiesel from oilseed rape revealed methyl esters of long-chain fatty acids as typical plant lipid constituents (Figure 14.3). The most prominent signal originated from the methyl ester of oleic acid (Ci i, m/z 296.4), accounting to 42.6% of the TII, followed by the methyl esters of linoleic acid (Ciga,m/z 294.4,23.8%), linolenic acid (Cm-,m/z 292.4,4.4%), stearic acid (Ci8 o, m/z 298.5, 2.8%), palmitic acid (Ci6 0, m/z 270.4, 1.4%), and gondoic acid (C2o i,... 

Nes, D.W. Biosynthesis and requirement for sterols in die growth and reproduction of Oomycetes. In Ecology and Metabolism of Plant Lipids. Fuller, G, Nes, W.D. ed., American Chemical Society, Washington, DC. 1987 pp. 304-328. 

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