Separation Strategies for Isoprenoids from Aqueous Solutions Term Paper

Separation Strategies for Isoprenoids from Aqueous Solutions - Term Paper Example The simplicity, cost and energy efficiencies as well as the separation capability of solvent extraction, make it the best among these techniques. Introduction Found in all classes of living organisms, isoprenoids are the largest and a diverse group of biomolecules. Also known as terpenoid, isoprenoids are derived from five-carbon isoprene units (2-methyl-1,3-butadiene) assembled and modified in thousands of ways (Encyclop?dia Britannica). In isoprenoids, two to thousands of the isoprene units, through one or neither of its double bonds, are linked into larger molecules to form linear or ring structures. As biomolecules, isoprenoids play a wide variety of roles in plant and animal physiological processes and as intermediates in the biological synthesis of other important biomolecules. The flavors, fragrances of essential oils and other plant-derived substances are due to these molecules. Geraniol, an isoprenoid, is a contributor to the fragrance of rose perfume. These molecules are al so extracted from plants or chemically synthesized to be used as pharmaceuticals (e.g. taxol, bisabolol, lycopene, artemisinin), animal feed supplements and food colorants (various carotenoids) For instance, lycopene is the red pigment in tomatoes while carotene, an isoprenoid and precursor of vitamin A, is responsible for the pigment in carrots. Given the biological importance and applications of these molecules, numerous chemical techniques have been developed for their isolation from their natural sources, which inevitably contains some amount of water. Conventional separation techniques such as distillation, fractional distillation, stream distillation, crystallization, solvent extraction, enfleurage, and chromatography are used. The chemical and physical properties of the compound as well as its abundance and distribution in nature, influenced the choice of technique. For instance, while volatile and plentiful isoprenoids such as turpentine are isolated by distillation of oleor esins, extremely rare compounds such as insect’s hormones are separated from the substrate by chromatography. Currently, fundamental research has been directed towards extraction of these molecules from their natural source by bioaccumulation in microorganism, from which these isoprenoids can be extracted (Clark, Maury and Asadollahi 29). This article seeks to discuss the various conventional and emerging separation techniques used for the separation of isoprenoids from aqueous substrate. This discussion will include overview of the underlying principle involved in the process, design considerations with respect to the technique, fundamental challenges associated with the technique and suggestion of the best technique with respect to performance, safety, cost, and energy efficiency. In addition, specific applications of the best technique will be given. Conventional separation techniques for the isolation of isoprenoids Conventional technologies employed include, simple disti llation, fractional distillation, stream distillation, vacuum distillation, solvent extraction, crystallization, and chromatographic techniques. Simple distillation Distillation involves the conversion of a liquid into vapor and the subsequent condensation of the vapor to back to liquid form. Distillation, as performed in the industry or laboratory is based differences in their volatilities (boiling point) of the mixture. Thus distillation is a physical separation process, and not a chemical reaction.