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The work detailed in this thesis is mainly concerned with the carbonylation of fatty acid derivatives, using carbon monoxide atmospheres in the presence of a transition metal. The two systems under study were the conversion of oleonitrile to a cyano-ester using a cobalt catalyst, and formation of isocyanates from amines in the presence of a palladium salt. The objectives of each study were: (i) to assess the influence of physical conditions on the reaction (i.e. pressure, time and temperature);(ii) to examine the effect of various additives on the system (i.e. phosphines, iodides and bases); and (iii) to identify any catalytic species observed under reaction conditions.Three major techniques were employed in each study: autoclave reactions, high pressure infra-red studies and atmospheric pressure nitrogen-line chemistry. The proposed underlying reaction mechanism was examined critically for each system, comparisons being drawn between the postulated catalytic species and those actually observed by high pressure infra-red spectroscopy. The chemical properties of the proposed catalytic intermediates are discussed in relation to the effect of co-reactants on the system. In the case of the carbonylation of oleonitrile the high pressure infra-red studies are consistent with the proposed reaction mechanism based upon the acyl complex RCOCo(CO)(_4). Although the infra-red study on the carbonylation of amines did not reveal any definite information, the results of other experiments were found to be consistent with a system based upon a carboxamido species L(_2)Pd(Cl)(CONRR').

Monounsaturated fatty acids (MUFA) have been viewed as either beneficial or neutral with respect to health; however, recent evidence suggests that MUFA may be associated with obesity and cardiovascular disease. Sex differences in MUFA composition have been reported in both rats and humans that may be mediated by sex hormones. Therefore, differences in fatty acid and enzyme expression were examined in male and female rats. HepG2 cells treated with 17β-estradiol, progesterone and testosterone (0, 10, 30 and 100 nM), and ovariectomized female rats with hormone implants (sham, no treatment, estradiol, progesterone, and estradiol plus progesterone) examined the role of sex hormones in MUFA metabolism. MUFA concentrations were determined by gas chromatography. The mRNA and protein expression of stearoyl-CoA desaturase and elongase 6, key enzymes involved in MUFA biosynthesis, were measured by real-time PCR and immunoblotting, respectively. Elongase 6 protein expression was higher in females as compared with males, increased with estradiol and progesterone treatment of HepG2 cells, and was higher in ovariectomized rats treated with estradiol. Elongase 6 expression was also decreased in HepG2 cells treated with testosterone. In contrast, the expression of stearoyl-CoA desaturase did not appear to be associated with sex or sex hormones in HepG2 cells, although ovariectomized rats treated with estradiol plus progesterone had increased stearoyl-CoA desaturase protein levels compared with sham controls. Sex differences and differences after hormonal treatments were observed in the fatty acid concentrations of MUFA and immediate MUFA substrates including 16:0, 16:1n-7, 18:0, 18:1n-7 and 18:1n-9. These differences in MUFA are consistent with the changes in elongase 6 expression. The effect of sex and hormone status on elongase 6 has not been previously examined, but these results suggest elongase 6 is an important factor in determining MUFA composition. These sex and hormonal differences in MUFA composition may contribute to sex differences in obesity and cardiovascular disease. Further work examining other factors involved in MUFA composition including oxidation, synthesis of complex lipids and the effect of diet is required.

Rainbow trout were fed semi-purified diets containing cyclopropenoid fatty acids, and the biological effects of these acids were investigated. These fatty acids occur naturally in cottonseed oil and have been implicated in a large number of physiological disorders. Included in this study was an investigation of the pattern of deposition of cyclopropenes per se in trout tissue lipids, as well as the effect of these cyclopropenes on the deposition of other fatty acids. Other effects such as growth, liver size and histology were also noted. The ingestion of methyl sterculate, 2-octyl-1-cyclopropene-1- octanoic acid, by rainbow trout resulted in the deposition of intact cyclopropene in the body tissue. The accumulation in both the muscle and depot lipid reached a level approximately equivalent to that in the diet. This cyclopropene existed as the unaltered sterculate in the tissue triglycerides as shown by GLC analysis and was approximately equal to that predicted by the Halphen determination. A method was developed whereby trout liver lipid could be quantitatively analyzed for CPFA using a modified Halphen color reaction. This method was limited, however, by the small amounts of lipid normally available in trout liver. Ingestion of CPFA by rainbow trout resulted in reduction of growth. This effect was characterized by a large growth suppression early in the feeding period followed by a more normal pattern of gain. Dietary levels of 100 ppm and 200 ppm methyl sterculate resulted in identical effects. Livers from trout fed CPFA were typically enlarged and very firm as compared to normal trout livers. They also displayed a marked lack of pigmentation. Histological examination revealed extreme damage due to increased fatty infiltration and deposition. This phenomenon appeared to be most extreme during the early stages of feeding. Dietary cyclopropenoid fatty acids induced certain changes in the pattern of fatty acid deposition in rainbow trout. This alteration was characterized by a rapid increase in the concentration of stearic acid in the tissue, which resulted in a change in the ratio of stearic to oleic acid. A similar but less pronounced effect was also observed with palmitic acid and palmitoleic acid. The liver triglycerides of trout fed CPFA for an extended period also contained less 22:6w3 than normal. When these fish were fed a CPFA-free control diet their liver lipids returned to normal within 30 days. / Graduation date: 1968

Atheroma, heart attacks and strokes continue to be a major cause of morbidity and mortality in our community. Atherosclerosis is a chronic inflammatory vascular disease, characterised by thickening of the vascular wall due to lipid accumulation, infiltration by circulating monocytes and T cells and proliferation of smooth muscle cells. Leukocyte adherence to the blood vessel wall is promoted by the up-regulation of cell adhesion molecules (CAM) by atherogenic substances such as tumour necrosis factor (TNF-α) and oxidised low density lipoprotein (oxidised-LDL). Recently our group has synthesised a novel polyunsaturated fatty acid, β-oxa 23:4n-6 which inhibits CAM up-regulation in blood vessel walls. It was therefore the objective of this thesis to determine whether this fatty acid protects against atherosclerosis. Advantage was taken of an experimental model of this disease, the apoE deficient mouse (apoE [superscript -/-]) which spontaneously develop atherosclerosis. To assist our studies on MP3, we established an appropriate classification of different stages of atherosclerotic lesions and defined the kinetics of development of the disease in this model. By examining of the sections at the level of aortic roots the atherosclerotic lesions were classified into six categories. This classification was based on the histological characteristics of the plaque component including the degree of macrophage infiltration and foam cells formation, the presence of cholesterol clefts and confluent lipid cores, calcification and ossification, the composition of the fibrous cap, the media involvement and the incipient/actual aneurysm formation and inflammation, including neutrophils. Kinetics of plaque development under the influence of a high fat and high cholesterol diet followed an exponential relationship of y= -e [ superscript -x ]. The asymptotic characteristic of this lesion development was however a function of compensatory aortic enlargement which accompanied the increase in lesion development and size. Thus it is concluded that the level of atherosclerosis needs to be gauged by the size of the lesion per se. This may be particularly important for the assessment of anti-atherogenic effects of drugs. Therefore attempts to develop a quantitative system to assess plaques revealed that expression of plaque size as % of occupation of blood vessel had limitations. Using this model we were able to demonstrate that injections of the novel polyunsaturated fatty acid, MP3 led to a significant reduction/inhibition (70%) of plaque area and a corresponding 60% inhibition of aortic size. As expected this inhibition was not as evident when results were expressed as % of aortic lumen size. The results also suggested that protection by MP3 was dependent on conditions which promoted increased uptake into tissues by, for example, preloading animals with MP3 prior to commencing the high fat high cholesterol diet. The protective effects of MP3 are consistent with a role for the activation of the transcriptional factor, NFkB and up-regulation of cell adhesion molecules in this disease, and the ability of MP3 to inhibit these targets. Thus the objective of this research has been achieved and the hypothesis proven. / Thesis (M.Med.Sc.)--Univesity of Adelaide, School of Paediatrics & Reproductive Health, 2005.

The size of the apiculture industry in Western Australia (W.A.) is one of the smallest in the nation but the production of pollen and honey per colony is the highest in Australia. The overwhelming value of the bee industry to the community is through pollination. The pollination service benefit provided by honey bees (Apis mellifera) in Australia has an estimated value of $AUS1.7 billion (1999 - 2000). The economic yields from crops, such as almonds and cucurbits, depend entirely on the activity of honey bees. Access to flora is essential to maintain productive colonies for pollination services. Pollen and nectar from flowers provide the nutritional components for colonies of honey bees to breed, but pollen is more important as it provides the colony with its source of protein. Protein content is changed by pollen lipid content which can vary from 0.8 to 18.9 %. Lipids are composed of fatty acids and a number are highly antimicrobial and play an important role in colony hygiene, whilst others are nutritionally crucial for honey bee development. Australian honey bee colonies utilise areas of native flora where a diversity of pollen species exist or hives are placed with agricultural crops that are based on European plants grown in monocultures, e.g. canola. Anecdotal evidence suggests that, in terms of breeding bees, some pollen species are much better than others and that bee health and longevity can be compromised if pollen is derived from single plant species. Protein analysis of pollen has been conducted on a wide range of species over the last two decades. However, lipid content and its analysis for fatty acids, which was reviewed for this thesis, have only been conducted on a few species. An initial investigation into the fatty acid composition of the pollen of W.A. eucalypts revealed the genus was characteristically high in linoleic acid concentration and ranged from 35.7 – 48 % (2.77 – 5.81 mg/g). Of the six species that are important to W.A. beekeepers, Eucalyptus wandoo (whitegum) and E. accedens (Powderbark Wandoo), a taxonomically similar species, showed similar levels of arachidic acid, whilst all three E. wandoo flowering varieties (summer, winter and spring) were the lowest in linolenic acid. Corymbia calophylla (redgum) was significantly higher in myristic and linolenic acids and E. patens (blackbutt), E. marginata (jarrah) and E. diversicolor (karri) had similar fatty acid profiles. European honey bees have evolved with plant species that have pollen that contain much higher levels of lipids, which are dominated by linolenic acid, than eucalypts. By contrast, the pollen of eucalypts, the most targeted plants by W.A. beekeepers, and other Australian plants are typically higher in linoleic than linolenic acid. Given the influence of lipids on protein content and that fatty acid concentration varied amongst some of the important eucalypt species, a much wider study of pollen from plant species that are important to beekeepers was conducted. The first aim of the project, a national pollen survey, was undertaken in which 577 samples of pollen were collected. A total of 73 different fatty acids were identified. Of these, only five: palmitic, stearic, oleic, linoleic and linolenic were common to all 577 samples of pollen. The second aim of the thesis was to investigate the effect of two commonly found fatty acids in pollen and their concentration at which longevity and life-span of honey bees, and development of the hypopharyngeal gland were deleteriously affected. An associated objective was to determine whether a range of soya bean flours, the main ingredient of an artificial bee diet that can replace pollen but differs in lipid concentration, had a similar effect. The aim encompassed two projects. In the first, two fatty acids (oleic and linoleic acid) were added at concentrations from 0 to 16 % to the low-fat, bee-collected pollen from C. calophylla. Eight different lipid-enhanced diets were created and each fed to bees confined in cages (mini-colonies containing 1400 bees). Oleic and linoleic acids were chosen because they are two of the five commonly found fatty acids in pollen. Oleic acid is the dominant fatty acid in honey bees and is a monounsaturated fatty acid. Linoleic acid is a dominant fatty acid in eucalypt pollen and is a polyunsaturated fatty acid that is one of two essential fatty acids that has antimicrobial activity. The second project revolved around the problem of maintaining bee populations when apiaries are in environments that lack floral abundance due to drought or other environmental catastrophes. In these situations, beekeepers maintain their colonies by supplying artificial feedstuffs to colonies of bees. The high-protein diet ingredient of choice is imported soya bean flour and three flours containing 0.6 % (protein concentrate), 1.8 % (defatted) and 18.9 % (full-fat) lipid, were used. Locally milled lupin flour, containing 6.9 % lipid, was tested as a possible replacement for imported soya bean flour. As for soya bean flour, lupin flour was used in pure form or mixed with pollen in diets fed to bees. Flour and pollen combinations created another ten different diets fed to bees the same way as the fatty acid-enhanced pollen diets. Along with the 8 lipid-enhanced and 10 flour and flour-pollen diets, there were two sugar-only diets, one mixed from dry cane sugar and the other, a liquid invert sugar. Two redgum pollen-only diets concluded the suite of 22 diets tested. One of these pollen diets was crushed and irradiated and was several years old whilst the other was collected fresh at the beginning of experimentation and kept frozen. Crushed and irradiated pollen is in common use by Australian commercial beekeepers as feedback when conditions for floral abundance are adverse. An early experimental result was an observation of distinctive bee behaviour after bees were confined in cages for six weeks where small but persistent numbers of bees were found hairless in samples. The behaviour was apparently the same as when single cohorts of emerged bees rearrange their caste repertoire, which has been reported elsewhere, but where no connection to head weight and caste type had been documented. Low head weight and hairlessness were strongly associated with each other. Low head weights are usually associated with foraging honey bees because the hypopharyngeal gland is no longer developed functionally. Experimentally, bees were assessed for longevity to 22 different diets in 7 experiments. Laboratory analysis was conducted on the weekly samples of bees removed from cages where bees were measured for head weight (hypopharyngeal gland development) and nutritional status by analysing de-gutted bees for protein, lipid, mineral and fatty acid content. Of the 22 diets tested, pure redgum pollen diets gave the greatest life-span and those bees fed diets of pure sugar had the shortest life. Honey bees fed a low-fat protein concentrate from soya bean flour had the longest life of the flours tested. Adding pollen to soya bean flour diets improved longevity whereas the addition of pollen to lupin flour caused increased mortality. Defatted and full-fat soya bean flours gave similar longevities and, despite large differences in fat content, the response to diet of head weight was negligible to the diets and no response was elicited by the queen bee to lay eggs which also indicated failed gland development of the worker bees. The addition of fatty acid (oleic and linoleic) to pollen at different concentrations caused significant differences in longevity. Overall, the addition of both fatty acids to pollen did not improve longevity. The addition of oleic acid to pollen greater than 2 % caused the longevity of bees to decrease, a poor head weight response and a failure of the queen to lay eggs. The addition of linoleic acid greater than 6 % to pollen diets had a similar response. As the percentage of oil was increased for both fatty acid additions, total consumption of the diet decreased. Honey bees fed soya bean, lupin flour and sugar-only diets failed to accumulate linoleic acid in their body which was in contrast to honey bees fed pollen diets. For the sugar diet, the failure of linoleic acid accumulation in bees occurred despite bees being able to accumulate total lipid. Manganese was poorly accumulated by honey bees fed both soya bean and lupin flour diets and a sugar-only diet. The implication is that linoleic acid and manganese need to be added separately to dietary formulations in a form as yet to be determined that will enable honey bees to accumulate these elements in the same way as bees do from consuming pollen. Soya bean flour-based diets, which have been used by beekeepers for decades, or lupin flour require additional amounts of linoleic acid and manganese. Similarly, this might apply to sugar. Sugar can be fed to bees in great quantities to enable bees to successfully over-winter in cold climates or it can allow breeding to commence which subsequently stimulates the collection of pollen. Sugar-feeding is widely promoted for orchard pollination, especially for kiwifruit. These changes could make these dietary ingredients more effective in enabling bees to breed between nectar flows and be more productive or nutritionally healthier, but any changes would require further cage experimentation. Bee-collected pollen naturally high in concentrations of oleic acid should also be tested in longevity trials, in conjunction with pollen that is low in oleic acid. The three untested common fatty acids (stearic, palmitic and linolenic acid) should also be evaluated for honey bee longevity and nutritional status.

Thesis (Ph. D.)--Columbia University, 1922. / Vita. "Reprinted from the Journal of Biological Chemistry, vol. XLVIII, no. 1, September, 1921, and vol. LI, no. 1, March, 1922." Part 1 appeared in Studies from the Rockefeller Institute, vol. XLI, p. 273-284.