Study on Biochemical Preparation of Natural and Rare Carbohydrate (Pentoses) (original) (raw)
Related papers
Production of natural and rare pentoses using microorganisms and their enzymes
Electronic Journal of Biotechnology, 2001
Biochemical methods, usually microbial or enzymatic, are suitable for the production of unnatural or rare monosaccharides. D-Arabitol was produced from Dglucose by fermentation with Candida famata R28. Dxylulose can also be produced from D-arabitol using Acetobacter aceti IFO 3281 and D-lyxose was produced enzymatically from D-xylulose using L-ribose isomerase (L-RI). Ribitol was oxidized to L-ribulose by microbial bioconversion with Acetobacter aceti IFO 3281; Lribulose was epimerized to L-xylulose by the enzyme Dtagatose 3-epimerase and L-lyxose was produced by isomerization of L-RI. L-ribose and L-arabinose were prepared biochemically from ribitol by oxidation using Acetobacter aceti IFO 3281 and isomerization using L-RI and L-arabinose isomerase (L-AI), respectively. Other pentoses can be produced as well by cell or enzyme bioconversions.
My Journey into the World of Carbohydrate Chemistry
My long journey in search of education and research in the realms of the chemistry of carbohydrates, such as sucrose and hyaluronic acid, took me through many parts of the world such as Bangladesh,. A brief description of the same is furnished hereunder. The two principal objectives of our research on carbohydrates were: (a) to understand the mechanism towards various chemical and enzymatic reactions and (b) to explore the commercial potential of the resulting carbohydrate derivatives. In this review, emphasis will mainly be placed on the second objective; and the inventions that followed as a result of the basic chemical and biochemical research on carbohydrates leading to the products of commercial significance, such as Sucralose ® (Splenda ®), a high-intensity sweetener.
Topics in Current Chemistry, 2010
This review is dedicated to wheat hemicelluloses and its main components D-xylose and L-arabinose as raw materials for fine organic chemistry. The context of the wheat agro-industry, its by-products, and extraction and hydrolysis of hemicelluloses to produce the pentoses are considered. The straightforward preparation of pentose-based surfactants, their properties, and their situation in the field of carbohydrate-based surfactants are addressed. Multistep transformations of pentoses are also described, first from a methodology point of view, with the aim of producing multifunctional enantiopure building-blocks, then considering targeted natural and/or bioactive products. Selected reactions of furfural, an important dehydration product of pentoses, are also presented.
ChemInform, 2011
The domain of bioactive natural products contains many oligosaccharides and aglycones decorated with various sugars. Glycan moieties influence essential aspects of biology of small molecules, such as mode of action, target recognition, pharmacokinetics, stability, and others. Methods of generation of novel glycosylated natural products are therefore of great value, as they, for example, may help fight human diseases more efficiently or provide healthier diet. This review covers the existing literature published mainly over the last decade that deals with biologybased approaches to novel glycoforms. Both genetic manipulations of biosynthesis of glycoconjugates and chemoenzymatic synthesis of novel "sweet" molecules are reviewed here. Wherever available, relationships between carbohydrate portions of the natural products and their biological activities are highlighted.
Some Disaccharide-derived Building Blocks of Potential Industrial Utility
Starch - Stärke, 1992
The utilization of inexpensive, bulk-scale accessible, renewable disaccharides as organic raw materials necessitates their practice-oriented conversion into products with different functional groups and, hence, broader application profiles. The backlog for the development of practical reaction channels to versatile building blocks from disaccharides being particularly obvious. Correspondingly, this account describes a series of examples by which the reaction potential inherent in disaccharides such as sucrose. lactose, maltose and isomaltulose is utilized towards the acquisition of versatile building blocks without cleaving the intersaccharidic linkage. -The glucose portion of sucrose, e.g. can be converted into dihydropyranones with the carbonyl function at C-2 or C-4, the reducing glucose parts of maltose and lactose may be transformed into enediolone, enelactone, or enollactone structures, whilst the fructose moiety of isomaltulose elaborates a furan ring by threefold, acid-induced elimination of water to yield the terminally 0-glucosylated HMF, i.e. glucosyloxymethyl-furan-2-carboxaldehyde. -All reaction sequences comply with criteria of practicallity and therefore being transformable to large scale without major changes. Another novel entry reaction into 0-functionabed disaccharide derivatives, the cathodic deprotonation and subsequent trapping of the mono-anion with suitable reagents according to Hamann. was evaluated in terms of understanding the regioselectivity attainable through computer simulations of relevant conformers of sucrose in solution, and the corresponding molecular electrostatic potential (MEP) profiles.
Chemoenzymatic and bioenzymatic synthesis of carbohydrate containing natural products
Topics in Current Chemistry, 2010
The domain of bioactive natural products contains many oligosaccharides and aglycones decorated with various sugars. Glycan moieties influence essential aspects of biology of small molecules, such as mode of action, target recognition, pharmacokinetics, stability, and others. Methods of generation of novel glycosylated natural products are therefore of great value, as they, for example, may help fight human diseases more efficiently or provide healthier diet. This review covers the existing literature published mainly over the last decade that deals with biologybased approaches to novel glycoforms. Both genetic manipulations of biosynthesis of glycoconjugates and chemoenzymatic synthesis of novel "sweet" molecules are reviewed here. Wherever available, relationships between carbohydrate portions of the natural products and their biological activities are highlighted.
Carbohydrate-Based Bioactive Compounds for Medicinal Chemistry Applications
Mini-Reviews in Medicinal Chemistry
In this article we review our work over the years on carbohydrates and carbohydrate mimetics and their applications in medicinal chemistry. In the first part of the review innovative synthetic methods, such as the chemoselective glycosylation method originally developed by our group and its applications to the synthesis of neoglycoconjugates (neoglycopeptides, oligosaccharide mimetics, neoglycolipids, etc … ) will be presented. The high density of functional groups (hydroxyls) on the monosaccharides and the structural role of sugars forming the core of complex glycans in scaffolding and orienting the external sugar units for the interaction with receptors, inspired us and others to use sugars as scaffolds for the construction of pharmacologically active compounds. In the second part of this review, we will present some examples of bioactive and pharmacologically active compounds obtained by decorating monosaccharide scaffolds with pharmacophore groups. Sugar-derived protein ligands were also used as chemical probes to study the interaction of their target with other proteins in the cell. In this context, sugar mimetics and sugar-derived compounds have been employed as tools for exploring biology according to the “chemical genetic” approach.
Carbohydrates as organic raw materials III
Carbohydrate Polymers, 1997
This book was carefully produced. Nevertheless. authors. editors. and publisher do not warrant the information contained therein to be free of errors. Readers are advised to keep in mind that statements. data, illustrations, procedural details or other items may inadvertently be inaccurate.