Litchi chinensis fatty acid diversity: occurrence of the unusual cyclopropanoic fatty acids

Litchi chinensis (Sapindaceae) is a tree that originates from China and is cultivated for its sweet fruits all over the world in warm climates. Unusual fatty acids such as cyclopropanoic fatty acids have been identified in the seeds of Litchi. Because of their potential value for industry (as inks, cosmetics, detergents, lubricants, etc.), the variability in the relative levels of unusual fatty acids in the seeds of 28 different Litchi varieties was analysed at two locations (on Réunion Island in the Indian Ocean) and on two different harvest dates. Except for one variety, all the seeds contained cis-9,10-methylene-octadecanoic acid (C(19)CA) at a relative level of 35-48%. The only variety that contained no or only traces of C(19)CA was Groff, seeds of which were significantly much smaller than those from all other varieties.     

Omega-3 fatty acids from fish oils and cardiovascular disease

Fish and fish oils contain the omega-3 fatty acids known as eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA). Epidemiological studies have shown an inverse relation between the dietary consumption of fish containing EPA/DHA and mortality from coronary heart disease. These relationships have been substantiated from blood measures of omega-3 fatty acids including DHA as a physiological biomarker for omega-3 fatty acid status. Controlled intervention trials with fish oil supplements enriched in EPA/DHA have shown their potential to reduce mortality in post-myocardial infarction patients with a substantial reduction in the risk of sudden cardiac death. The cardioprotective effects of EPA/DHA are widespread, appear to act independently of blood cholesterol reduction, and are mediated by diverse mechanisms. Their overall effects include anti-arrhythmic, blood triglyceride-lowering, anti-thrombotic, anti-inflammatory, endothelial relaxation, plus others. Current dietary intakes of EPA/DHA in North America and elsewhere are well below those recommended by the American Heart Association for the management of patients with coronary heart disease. (Mol Cell Biochem 263: 217–225, 2004)     

The distribution of fatty acids including petroselinic and tariric acids in the fruit and seed oils of the Pittosporaceae, Araliaceae, Umbelliferae, Simarubaceae and Rutaceae

The fatty acid composition of the fruit oils or seed oils of Pittosporaceae (eight genera, 10 species), Araliaceae (two species), Simarubaceae (three species), and of one umbelliferous and one rutaceous species were determined by gas chromatography, argentation TLC and ozonolysis. In the Pittosporaceae, in which the major C₁₈ fatty acid of all species was either oleic acid (18:1, 9c) or linoleic acid (18:2, 9c, 12c), large amounts of C₂₀ and C₂₂ fatty acids seem to occur regularly. Petroselinic (18:1, 6c) and tariric (18:1, 6a) acids were absent. However, petroselinic acid was the major fatty acid in the Araliaceae and Umbelliferae. In these two families only small amounts of C₂₀ and C₂₂ acids were detected and tariric acid was absent. The Rutales contained relatively high amounts of trans-octadecenoic acids (18:1, 9t). Tariric acid was the major fatty acid in the two species of Picramnia (Simarubraceae), which also contained small amounts of petroselinic acid. The major fatty acids in Ailanthus glandulosa (Simarubaceae) and Phellodendron amurense (Rutaceae) were linoleic or linolenic acid (18:3, 9c, 12c, 15c); these species contained neither tariric nor petroselinic acid and the levels of C₂₀ and C₂₂ fatty acids were low. The appearance of schizogenous resin canals and polyacetylenes and the absence of iridoids and petroselinic acid allows the Pittosporaceae to be separated from the Rutales and Araliales and to be placed in an independent order, the Pittosporales. Arguments for a rather close relationship of the Pittosporales to the Araliales and Cornales (including the Escalloniaceae) are presented.     

Rare fatty acids and lipids in plant oilseeds: occurrence and bioactivity

Phytochemistry Reviews - Lipids are biomolecules which are present in plants as general metabolites with different functions such as structural, protective and also as storage material. Plants...     

Ecogeographic variation in seed fatty acids of Austrocedrus chilensis

Seed megagametophyte fatty acids were analyzed for proportional composition in 104 trees from 13 natural populations of Austrocedrus chilensis in Andean Chile and Argentina, using gas-liquid chromatography. A total of 15 fatty acids were identified from their methyl esters by GC retention times and by mass spectroscopy and included, as major compounds, oleic, linoleic, linolenic and cis-5,11,14,17-eicosatetraenoic acids. Multivariate analyses indicated a separation of xeric zone populations (mediterranean Chile and the Argentinean steppe ecotone) from mesic populations (Argentinean Lakes and southern range in Chilean rainforest). These differences were associated with a greater abundance of C20 unsaturated rated acids in the mesic group. Differentiation among mediterranean Chilean populations was relatively high, perhaps as a result of their disjunct distribution. There was no evidence for lower levels of within-population variation for these isolated northern populations.     

Lipase-catalyzed esterification of glycerol and polyunsaturated fatty acids from fish and microalgae oils

This paper reports on the synthesis of triglycerides by enzymatic esterification of polyunsaturated fatty acids (PUFA) with glycerol. The lipase Novozym 435 (Novo Nordisk, A/S) from Candida antarctica was used to catalyze this reaction. The main factors influencing the degree of esterification and triglyceride yield were the amount of enzyme, water content, temperature and glycerol/fatty acid ratio. The optimum reaction conditions were established as: 100 mg of lipase; 9 ml hexane; 50°C; glycerol/PUFA concentrate molar ratio 1.2:3; 0% initial water; 1 g molecular sieves added at the start of reaction; and an agitation rate of 200 rpm. Under these conditions, a triglyceride yield of 93.5% was obtained from cod liver oil PUFA concentrate; the product contained 25.7% eicosapentaenoic acid and 44.7% docosahexaenoic acid. These optimized conditions were used to study esterification from a PUFA concentrate of the microalgae Phaeodactylum tricornutum and Porphyridium cruentum. With the first, a triglyceride yield of 96.5%, without monoglycerides and very few diglycerides, was obtained after 72 h of reaction; the resulting triglycerides had 42.5% eicosapentaenoic acid. A triglyceride yield of 89.3% was obtained from a P. cruentum PUFA concentrate at 96 h of reaction, which contained 43.4% arachidonic acid and 45.6% EPA. These high triglyceride yields were also achieved when the esterification reaction was scaled up 5-fold.     

New tropical seed oils. Part I. conjugated trienoic and tetraenoic acids and their oxo derivatives in the seed oils of Chrysobalanus Icaco and Parinarium Laurinum

The seed oils from Chrysobalanus icaco and Parinarium laurinum contain the following acids (% wt.): palmitic (4,4), stearic (18,7), oleic (11,2), linoleic (6,2), arachidic (1,0), conjugated octadecadienoic (0,1), α-eleostearic (22,22), α-parinaric (10,62), α-licanic (10,0) and a hitherto unknown acid (18,0) which is proved to be 4-oxo-octadeca-cis-9, trans-11, trans-13, cis-15-tetraenoic acid. α-Parinaric acid from both these sources is the cis-9, trans-11, trans-13, cis-15 isomer.     

FTIR determination of free fatty acids in fish oils intended for biodiesel production

Biodiesel is commonly derived from vegetable oils and animal (fish and livestock) fats by alkali- or lipase-catalyzed transesterification reactions. Since free fatty acid (FFA) content is a critical parameter in the conversion of fish oils to methyl esters, the performance of a Fourier transform infrared (FTIR) spectroscopic method was assessed as an alternative to the conventional AOCS titrimetric method. The FTIR method involves the simultaneous extraction of FFAs and their stoichiometric conversion to their salts using a weak base, sodium hydrogen cyanamide (NaHNCN) dissolved in methanol, followed by measurement of the carboxylate band, ν(COO^?), at 1573 cm^?1 relative to a baseline at 1820 cm^?1 in the differential spectrum of the methanol extract. With minor modifications, this method was found to be capable of responding linearly to oleic acid (0–6.5%) addition, producing a FFA calibration equation having a S.D. of ±0.014% FFA. FTIR and titrimetric analytical results were compared for samples prepared by standard addition as well as for fish oils extracted from salmon skin which had been stored up to 120 days at ?20 °C. Both methods responded in a comparable manner; however, the FTIR method was more reproducible and accurate as well as simpler to carry out and was deemed to be a better primary method than the titrimetric method. The FFA content of Atlantic salmon (Salmo salar) skin lipids increased linearly from ～0.6% to 4.5% within 120 days, likely as a result of autoxidation. It was concluded that the NaHNCN-based FTIR method is a flexible, viable instrumental alternative to the AOCS titrimetric procedure for the determination of FFA content of fish tissue lipids destined for biodiesel production.