China
Africa
Explore chapters and articles related to this topic
Production and Modification of PHA Polymers Produced from Long-Chain Fatty Acids
Published in Martin Koller, The Handbook of Polyhydroxyalkanoates, 2020
Chris Dartiailh, Nazim Cicek, John L. Sorensen, David B. Levin
The double bonds of MUFAs and PUFAs are removed as the chain is shortened using the fatty acid degradation pathway. The enzyme cis-3,trans-2,enoyl-CoA isomerase is responsible for removing the odd-carbon double bonds, while even-numbered double bonds (such as the Δ12 olefin group of linoleic acid) are removed by 2,4-dienoyl-CoA reductase [28]. In this way, one may predict the position of double bonds in the PHA polymer based on the substrate provided and the monomer length. For instance, 15.5 mol-% of mcl-PHA synthesized by P. putida KT2442 grown with oleic acid (Δ9) was monounsaturated, as the olefin was maintained in the C14 monomers, compared with no retained olefins from petroselinic acid (Δ6). Growth on linoleic acid (Δ9, Δ12) tripled the unsaturation of PHA as both olefins were maintained in the C14, and one olefin remained in C12 [28]. Moreover, PHA produced from linolenic acid (Δ9, Δ12, Δ15) produced highly unsaturated PHA containing mono-(C8, C10), di-(C12), and poly-(C14) unsaturated monomers [30]. Table 11.1 illustrates that the average monomer length and mol-% of unsaturated monomers increased proportionally with the length and unsaturation of the substrate. Hydroxyl and epoxy moieties have also been observed in mcl-PHA when P. aeruginosa 44T1 was provided with castor or euphorbia oil [92]. Mcl-PHA have incorporated halogen, hydroxyl, carboxyl, thiol, epoxy, aromatic, and branched moieties, to name a few, using the appropriate fatty acids [11,12,91]. These functional properties provide the basis for modification of unsaturated mcl-PHA, but their inclusion also broadens the applicable chemical modifications.
Biochemistry
Published in W. M. Haynes, David R. Lide, Thomas J. Bruno, CRC Handbook of Chemistry and Physics, 2016
W. M. Haynes, David R. Lide, Thomas J. Bruno
Mol. form. C4H8O2 C5H10O2 C5H10O2 C6H12O2 C7H14O2 C8H16O2 C9H18O2 C10H20O2 C10H18O2 C11H22O2 Lauric acid Lauroleic acid Myristic acid Myristoleic acid Palmitic acid Palmitoleic acid Margaric acid Stearic acid Petroselinic acid Oleic acid Elaidic acid cis-Vaccenic acid Vaccenic acid Vernolic acid Ricinoleic acid Rumenic (CLA) Linoleic acid C12H24O2 C12H22O2 C13H26O2 C14H28O2 C14H26O2 C15H30O2 C16H32O2 C16H30O2 C17H34O2 C18H36O2 C18H34O2 C18H34O2 C18H34O2 C18H34O2 C18H34O2 C18H32O3 C18H34O3 C18H32O2 C18H32O2 4:0 5:0 4:0 3-Me 6:0 7:0 8:0 9:0 10:0 10:1 9e 11:0 12:0 12:1 9c 13:0 14:0 14:1 9c 15:0 16:0 16:1 9c 17:0 18:0 18:1 6c 18:1 9c 18:1 9t 18:1 11c 18:1 11t 18:1 12,13-ep,9c 18:1 12-OH,9c 18:2 9c,11t 18:2 9c,12c
Decarboxylation of cinnamic acids using a ruthenium sawhorse
Published in International Journal of Sustainable Engineering, 2018
Kenneth M. Doll, Erin L. Walter, Rex E. Murray
The scope of this reaction system has been further explored. Nitrogen containing substrates were utilised, including trans-4-dimethylamino cinnamic acid (99%, Sigma-Aldrich, St. Louis, MO) and nicotinic acid (98%, Sigma-Aldrich, St. Louis, MO), the latter being decarboxylated in a stainless steel reactor. In the dimethylamino case, insolubility prevented the reaction from occurring, again demonstrating that this is a truly homogeneous reaction. Nicotinic acid was decarboxylated in 29% yield. As a final comparison, cis-9-octadecenoic acid (oleic acid, (Nu-Check Prep, Elsyian, MN > 99%), trans-9-octadecenoic acid (elaidic acid > 99%, Nu-Check Prep, Elsyian, MN) and cis-6-octadecenoic acid (petroselinic acid (>99%, Nu-Check Prep, Elsyian, MN) were found to have identical reactivity using this catalyst in a stainless steel reactor.