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Published in Brajendra K. Sharma, Girma Biresaw, Environmentally Friendly and Biobased Lubricants, 2016
Kenneth M. Doll, Bryan R. Moser, Zengshe Liu, Rex E. Murray
The principal fatty acid in castor oil is ricinoleic acid (Figure 5.4), which is both hydroxylated and unsaturated. As a consequence of its unique multifunctional composition, castor oil is used extensively as an industrial oil. In addition to sebacic acid mentioned previously, ricinoleic acid is used to produce a variety of products including estolides via polycondensation; polyols by transesterification with diols or other polyhydroxylated compounds; 10-hydroxydecanoic acid by low-temperature alkali cleavage; and 10-undecenoic (undecylenic) acid from pyrolysis [68,77,78]. Undecylenic acid is used as a platform chemical for the production of numerous monomers [79]. For example, polyamide 11 is obtained from 11-aminoundecanoic acid, which is prepared via an 11-bromo intermediate [68,77,78]. Dienoic monomers suitable for free radical or acyclic diene metathesis polymerization have also been prepared from undecylenic acid. These include allyl, vinyl, acrylic, and methacrylic ethers and esters, all of which have applications in the coatings industry [80]. Dienes suitable for acyclic diene metathesis polymerization include 10-undecenyl undecylenate and undecylenic acid moieties esterified to phosphorus-containing heteroaromatic cores as comonomers for flame-resistant polyesters [81,82]. Finally, a variety of renewable monomers can be prepared via thiol-ene click chemistry in which thiolated compounds are added to undecylenic acid via a free radical mechanism to yield anti-Markovnikov products [83]. Such monomers are useful for production of ultraviolet (UV)–curable resins and coatings. Specific examples of monomers from undecylenic acid include those derived by addition of butanedithiol, thioacetic acid, thioglycerol, 4-hydroxybutanethiol, and methyl 2-mercaptoacetate, among others [83–85]. Methyl 9-decenoate (Figure 5.5 and next subsection), prepared by cross metathesis of methyl oleate with ethene (ethenolysis), represents the 10-carbon analogue of methyl 10-undecenoate [86].
Triphasic partitioning of mixed Scenedesmus and Desmodesmus for nutrients’ extraction and chlorophyll composition prediction for algae bloom
Published in Environmental Technology, 2022
Doris Ying Ying Tang, Kit Wayne Chew, Shir Reen Chia, Huong-Yong Ting, Yuk-Heng Sia, Francesco G. Gentili, Zengling Ma, Mukesh Kumar Awasthi, Pau Loke Show
The gravimetric analysis showed that the lipid content of microalgae was about 6.57% of the microalgae biomass. As shown in Figure 3, the lipid profile obtained from gas chromatography showed that the highest peak was seen for C11 (0.1870 mg/g), followed by C16 (0.0459 mg/g), C12 (0.0053 mg/g) and lastly C20 (0.0012 mg/g). The gas chromatography analysis results revealed that the fatty acid methyl ester profiles of the mixed microalgae species contain abundant saturated fatty acids (undecanoic acid, lauric acid) as compared to unsaturated fatty acids (palmitoleic acid and eicosapentaenoic acid). The highest weight was found in C11 (undecanoic acid), whereas the lowest was C20 (eicosapentaenoic acid). The performance of this assay can be enhanced by increasing the sensitivity in the detection of compound or mass spectrometry methods to verify the compounds. This was supported by the findings from Chaudhary and Khattar [39] that showed Desmodesmus subspicatus biomass contained high saturated fatty acids (47%) under nitrogen limitation as compared to monounsaturated fatty acids (30%) and polyunsaturated fatty acids (23%). Gour and Chawla [40] studied Scenedesmus dimorphus biomass and stated that it had a higher occurrence of saturated fatty acids (53.04%) than monounsaturated fatty acids (23.81%) and polyunsaturated fatty acids (19.69%). This result agreed well with previous studies wherein the lipid and carbohydrate yield of Scenedesmus obliquus was around 16.0% and 20.4%, respectively with a biomass concentration of 71.6 mg L−1 [41,42]. In pharmaceutical industries, different fatty acids possess their individual functions, such as omega-3 fatty acids, eicosapentaenoic acid and docosahexaenoic acid, and have important roles in cardiovascular disease risk management. However, the mixed microalgae species used in this study comprised lower amounts of eicosapentaenoic acid as compared to saturated fatty acids and undecanoic acid. Undecanoic acid or undecylenic acid can be used as antifungal agents in topical antifungal formulas for the treatment of dermatomycosis, onychomycosis, and tinea pedis and is normally extracted from Candida albicans [43]. Therefore, the abundance of this fatty acid in these mixed microalgae species suggests it an alternative microorganism to extract undecanoic acid for making active ingredients for topical treatments.