Glycosides and their Derivatives

Na+/K+-ATPase. Figure 5 Cardiac glycosides and their derivatives with anti-cancer action. 

We have studied hemolytic action of a series of triterpene glycosides and their derivatives (3-15) from sea cucumbers belonging to the order Dendrochirotida [33]. 

To investigate the influence of quantity and position of sulfate groups in carbohydrate moieties, we have studied kinetic parameters of hemolysis and loss from erythocytes of another series of triterpene glycosides and their derivatives from sea cucumbers in the order Dendrochirotida [34]. 

Miyamoto et al. have studied the antifungal activity of glycosides and their derivatives from Cucumaria echinata [49]. The results are shown in Table 6. 

Table 6. Minimal growth inhibitory concentration ( lg/ml) for glycoside and their derivatives from Cucumaria echinata...

Holothurinosides A (75), C (76) and D (77) are native substances, whereas (78) - is a derivative, obtained by partial acid hydrolysis of holothurinoside A. The data on cytotoxic activity against tumor cells of these glycosides and their derivatives are shown in the Table 8. 

The generic term monosaccharide (as opposed to oligosaccharide or polysaccharide) denotes a single unit, without glycosidic connection to other such units. It includes aldoses, dialdoses, aldoketoses, ketoses and diketoses, as well as deoxy sugars and amino sugars, and their derivatives, provided that the parent compound has a (potential) carbonyl gTOup. 

Consequences of the conformational anomeric effect are largely expressed in monosaccharides and their derivatives. One recognizes the conformational endo-anomeric effect for pyranosides with a polar X group at C(l) (contrasteric electronic stabilization effect Fig. 7A) and conformational exo-anomeric effect for glycosides (acetals) in which the alkyl group of the exocyclic moiety is synclinal (Fig. 7B, C). 

Reduction of aldonolactones and their derivatives with isotopically modified reducing agents leads to sugars labeled at the anomeric center. Glycosides substituted with deuterium or labeled with tritium are widely employed for kinetic isotope-effect measurements, mechanistic studies, isotope-tracing experiments, and so on. 

Dimeric anthraquinone and their derivatives are also present as aglycones in anthraquinone glycoside found in the plant kingdom. 

Flavonoid glycosides and their esters are an important group of natural compounds isolated from plants. They are widely used in pharmaceutical, cosmetic, and food preparations, and it is therefore not surprising that the search for new derivatives with improved antioxidant and antimicrobial activity, or-more sim-ply-with more suitable physico-chemical properties for specific applications (i.e., increased stability and/or solubility), has identified enzyme-catalyzed regioselective esterification as a particularly promising approach to the target molecules [21a],... 

Much of the interest in alkylation of compounds 4 and 5 and their derivatives is centered on the formation of D-ribofuranosyl derivatives. Compound 4 reacts with formaldehyde to give the 1-hydroxymethyl derivative 223167 and with mercuric chloride and tribenzoyl-D-ribofuranosyl chloride to give the three jV-glycosides 224-226,216 with the N-3 isomer predominating. The... 

Identification, isolation, and removal of (polyhydroxy)benzenes from the environment have received increased attention throughout the 1980s and 1990s. The biochemical activity of the benzenepolyols is at least in part based on their oxidation—reduction potential. Many biochemical studies of these compounds have been made, eg, of enzymic glycoside formation, enzymic hydroxylation and oxidation, biological interactions with biochemically important compounds such as the catecholamines, and humic acid formation. The range of biochemical function of these compounds and their derivatives is not yet fully understood. 

Most of the signals are assigned by comparison of the chemical shifts of analogous series of sugars and their derivatives such as glycosides and nucleosides. 

Tables II to X give the melting points and, where applicable, the optical rotations of the inositols, inososes, inosamines, and quercitols, and of all of their known O-substituted derivatives. Anhydroinositols, although not substitution products in the strict sense, are included, as are the carbonyl-functional derivatives of the inososes. Halogen- and nitro-substituted cyclitols, and the C-methyl-inositols and their derivatives, are not included most of these compounds are referred to in the text. The derivatives are arranged in the following order salts (inosamines) or functional derivatives (inososes), carboxylic esters, borates, nitrates, sulfonic esters, phosphates, glycosides, acetals (and Schiff bases), ethers (and IV-alkyl derivatives), and anhydrides.

---