Carbohydrates, acidic derivatives

In 1941 Gakhokidze40 realized a different type of Grignard synthesis on a carbohydrate acid derivative. Methyl L-ery(liro-3,4,5-trimethoxy-2-oxovalerate (XXXII), was treated with one mole of methylmagnesium iodide to produce methyl 2-methyl-2-hydroxy-L-er /(firo-3,4,5-trimethoxy-valerate (XXXIII). The configuration of the second carbon atom in... 

Stacey started research in an inspiring and stimulating atmosphere that he strove to maintain, add to, and develop when it became his turn to lead the department. His earliest research was with Haworth and his key partner E. L. Hirst [Adv. Carbohydr. Chem. Biochem., 35 (1978) 1 -29] on aspects of the chemistry of glucoheptose. His first publication with them in 1931 was entitled Walden Inversion in the a-Glucoheptose Series, followed in the next year by a report on the methylation of monocarboxylic acids derived from aldoses and the structure of pentamethyl a-gluco-heptonolactone. He found this to be a difficult project because, initially, he could not crystallize his stock of glucoheptose. Then, as later, he found crystallization to be a challenging problem. 

Note 2. To maintain integrity of carbohydrate names, it is sometimes helpful to overstep the strict order of principal group preference specified in general organic nomenclature [13,14]. For example, a carboxymethyl-substituted sugar can be named as such, rather than as an acetic acid derivative (see 2-Carb-31.2). 

Plants were probably the first to have polyester outerwear, as the aerial parts of higher plants are covered with a cuticle whose structural component is a polyester called cutin. Even plants that live under water in the oceans, such as Zoestra marina, are covered with cutin. This lipid-derived polyester covering is unique to plants, as animals use carbohydrate or protein polymers as their outer covering. Cutin, the insoluble cuticular polymer of plants, is composed of inter-esterified hydroxy and hydroxy epoxy fatty acids derived from the common cellular fatty acids and is attached to the outer epidermal layer of cells by a pectinaceous layer (Fig. 1). The insoluble polymer is embedded in a complex mixture of soluble lipids collectively called waxes [1], Electron microscopic examination of the cuticle usually shows an amorphous appearance but in some plants the cuticle has a lamellar appearance (Fig. 2). 

Click chemistry has been particularly active in various fields this year. For example, ample applications of click chemistry have been seen in carbohydrate chemistry. Various /weiido-oligosacchardies and amino acid glycoconjugates were synthesized via an intermolecular 1,3-dipolar cycloaddition reaction using easily accessible carbohydrate and amino acid derived azides and alkynes as building blocks <06JOC364>. The iterative copper(I)-catalyzed... 

Nobmann P, Smith A, Dunne J, Henehan G and Bourke P. 2009. The antimicrobial efficacy and structure activity relationship of novel carbohydrate fatty acid derivatives against Listeria spp. and food spoilage microorganisms. Int J Food Microbiol 128(3) 440—445. 

The common methods of esterification utilize an acid chloride or an acid anhydride as the reagent, but other acid derivatives often show different selectivities, and these are also considered here. In view of the extensive articles on sulfonic esters of carbohydrates,2 4... 

The binding affinity of carbohydrate-mimetic peptides can be quite high, often higher than the natural carbohydrate ligand. Carbohydrate-mimetic peptides do not share any general chemical features, and all amino acid residues are represented there is no evidence for an unusual importance of aromatic residues in mimicry. In several cases, o-amino acids have been incorporated, and unusual amino acids (derived from nonribosomal peptide synthesis) have been found in naturally occurring carbohydrate-mimetic peptides. 

Carbohydrates are certainly important in their own right as key intermediates in cellular metabolism as an essential stractural feature of the nucleic acids as sources of energy as energy reserves for maintenance of structure for lubrication of joints and for other purposes. However, carbohydrates are neither limited to these functions nor confined to the stractures we have developed thus far. Indeed, many of their roles, and much of the excitement associated with carbohydrate chemistry, derives from the properties of their conjugates with other classes of molecules, notably those with lipids and those with proteins. 

Carbohydrate detection is important for applications such as glucose monitors these are arguably one of the most successful and relevant biosensors. An interesting fluorescence recovery-type saccharide sensor based on the reactivity of carbohydrates with boronic acids was reported in 2002 [36]. Specifically, modification of the cationic viologen-linked boronic acid derivative 40 to a zwitterionic species 41 upon covalent and reversible reaction of boronic acid with monosaccharides (Scheme 1) can cause the dissociation of the ion-pair in-... 

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