V. P. Glazunov

Anthraquinone production by callus cultures of Rubia cordifolia

Abstract Munjistin and purpurin were identified as the major components of anthraquinone pigments produced by callus cultures of R. cordifolia. Anthraquinone content in calluses was 0.62–1.22% (by dry wt.) depending on the source of explants. Selection of coloured aggregates yielded a cell line with twofold increase in anthraquinone production.

Structural peculiarities of polysaccharide from sterile form of Far Eastern red alga Ahnfeltiopsis flabelliformis.

KCl-insoluble sulfated polysaccharide from sterile alga Ahnfeltiopsis flabelliformis was investigated. Partial reductive hydrolysis and NMR spectroscopy showed that the polysaccharide comprises disaccharide units of carrabiose only. According to FT-IR-, 1D, 2D NMR spectroscopies and mass-spectrometry this polysaccharide is kappa/beta-carrageenan with ratio of kappa- and beta-types units 3:1 and contains minor amounts of iota- and gamma-carrageenans (precursor of beta-carrageenan). In addition, ESIMS/MS data suggested that xylose (minor amount) is present in the polysaccharide as a substituent one of hydroxyl group of galactose. According to aPTT and PT assays the studied carrageenan affected mostly intrinsic pathway of coagulation, while it effect on the extrinsic pathway is absent.

A Convenient Method for the Selective Alkylation ofβ-OH Groups of 2(3)-Hydroxyjuglones and Hydroxynaphthazarines

Abstract Trimethyl-and triethylorthoformates have been used for the selective alkylation of β-OH groups of 2(3)-hydroxy-3(2)-alkyljuglones, 2-hydroxy-3-alkyl-, 2-hydroxy-3-chloro-, and 2,3-dihydroxynaphthazarines (1a-o,3,4). In most cases the corresponding alkoxy compounds (2a-q,5,6) were obtained in good yields. However, when 2-hydroxynaphthazarine (1p) was used, the formation of monomethineoxonol derivative (9) as the principal product took place.

Structural analysis and cytokine-induced activity of gelling sulfated polysaccharide from the cystocarpic plants of Ahnfeltiopsis flabelliformis.

Gelling sulfated polysaccharide from the cystocarpic plants of Ahnfeltiopsis flabelliformis was studied. According to FT-IR and NMR spectroscopy data, the polysaccharide was found to be iota/kappa-carrageenan with iota- and kappa-type units in a 2:1 ratio containing beta-carrageenan units and minor amounts of nu- and mu-carrageenans. The HPLC and ESI MS/MS data of enzymatic hydrolysis products revealed that the main components of the polymer chain are iota-carrabiose, iota-carratetraose and hybrid tetra- and hexasaccharides consisting of kappa- and iota-units. Xylose was a substituent of a hydroxyl group at C-6 of 1,3-linked β-d-galactose in the total polysaccharides. It was shown that the ability of carrageenans to increase the synthesis of cytokines depended on their molecular weight. The polysaccharide induced the synthesis of the anti-inflammatory cytokine IL-10, whereas oligosaccharides increased the synthesis of both pro- and anti-inflammatory cytokines at high concentrations.

Polysaccharide structure of tetrasporic red seaweed Tichocarpus crinitus

Sulfated polysaccharide isolated from tetrasporic plants of Tichocarpus crinitus was investigated. The polysaccharide was isolated by two methods: with water extraction at 80 °C (HT) and with a mild alkaline extraction (AE). The extracted polysaccharides were presented by non-gelling ones only, while galactose and 3,6-AG were the main monosaccharides, at the same time amount of 3,6-AG in AE polysaccharides was the similar to that of HT. According to methods of spectroscopy and mass spectrometry, the polysaccharide from tetrasporic T. crinitus contains main blocks of 1,3-linked β-D-galactopyranosyl-2,4-disulfates and 1,4-linked 3,6-anhydro-α-D-galactopyranosyl while 6-sulfated 4-linked galactopyranosyl resudies are randomly distributed along the polysaccharide chain. The alkaline treatment of HT polysaccharide results in obtaining polysaccharide with regular structure that composed of alternating 1,3-linked β-D-galactopyranosyl-2,4-disulfates and 1,4-linked 3,6-anhydro-α-D-galactopyranosyl residues. Native polysaccharide (HT) possessed both high anticoagulant and antiplatelet activity measured by fibrin clotting and platelet aggregation induced by collagen. This activity could be connected with peculiar chemical structure of HT polysaccharide which has high sulfation degree and contains also 3,6-anhydrogalactose in the polymer chain.

Synthesis and structure elucidation of oxidative coupling products of 2-hydroxy-1,4-naphthoquinones

Abstract2,3-Dihydro-3-O-(1,4-naphthoquinon-2-yl)-2-oxo-1,4-naphthoquinones are the products of oxidative coupling of substituted 2-hydroxy-1,4-naphthoquinones (regardless of the presence of peri-hydroxy groups in their structures) under the action of lead dioxide.

Chemistry of naphthazarin derivatives. 8. Determination of structures of substituted 2-hydroxy-6(7)-methoxynaphthazarins and 7(8)-hydroxypyranonaphthazarins by IR spectroscopy

A set of substituted 2-hydroxy-6(7)-methoxynaphthazarins and 7(8)-hydroxypyranonaphthazarins were synthesized. The IR spectra of 2-hydroxy-6-methoxynaphthazarins and 7-hydroxypyranonaphthazarins, on the one hand, and of 2-hydroxy-7-methoxynaphthazarins and 8-hydroxypyranonaphthazarins, on the other hand, have the characteristic nonoverlapping intervals of stretching vibration frequencies of the β-hydroxy groups. These regularities confirm the structures of cristazarin and 6-methylcristazarin, which are metabolites of lichen Cladonia cristatella.

Selective Chlorination of Hydroxynaphthazarins with Dichlorine Monoxide. Remarkable Stability of some Geminal Diols Derived from 2,3-Dihydro-2-oxonaphthazarin

Abstract The ration of 2-hydroxynaphthazarins with dichlorine monoxide in CC14 affords the stable gem-diols - 3,3-dichloro-2,3-dihydro-2,2-dihydroxy-paphthazarins in quantitative yields. In the case of 2-hydroxy-3-methyl-iiaphthazarins the formation of the mixture of corresponding monochlorinated at 3 position 2,3-dihydro-3-methyl-2-oxonaphthazarins and 2,3-dihydro-3-methyl-2,2-dihydroxynaphthazarins takes place. For these compounds, under certain conditions, the keto - gem-diol equilibrium is observed.

THE CHEMISTRY OF NAPHTHAZARIN DERIVATIVES. 3. SYNTHESIS OF THE DIDEOXY ANALOG OF ISLANDOQUINONE

The 7,7′-dideoxy analog of islandoquinone, binaphthazarin of a new structural type, bearing a 2-oxo-2,3-dihydro-1,4-naphthoquinone moiety was synthesized. The carbonyl group at the C(2) atom of this binaphthazarin easily adds water to give the correspondinggem-diol. Comparison of the spectral characteristics of the prepared diol and islandoquinone made it possible to elucidate more precisely the structure of the latter.

Carrageenans-Sulfated Polysaccharides from Red Seaweeds as Matrices for the Inclusion of Echinochrome

The possibility of using different types of carrageenans (CRG) as matrixes for incorporating of echinochrome A (Ech) was investigated. Ech interacts with carrageenans and is incorporated into the macromolecular structure of the polysaccharide. The inclusion of Ech in carrageenan matrices decreased its oxidative degradation and improved its solubility. The changing in the charge and morphology of CRGs during binding with Ech was observed. The rate of Ech release from CRG matrices depended on the structure of the used polysaccharide and the presence of specific ions. The gastroprotective effect of CRG/Ech complexes was investigated on the model of stomach ulcers induced by indomethacin in rats. Complexes of CRG/Ech exhibited significant gastroprotective activity that exceeded the activity of the reference drug Phosphalugel. The gastroprotective effect of the complexes can be associated with their protective layer on the surface of the mucous membrane of a stomach.