Seasonal variations of the composition,structural features,and antitumor properties of polysaccharides from <Emphasis Type="Italic">Padina pavonica</Emphasis> (Lebanon) as a function of composition

The variation of the polysaccharide composition of the brown alga Padina pavonica from the Mediterranean Sea was studied as a function of the collection season (April–July). It was shown that the principal polysaccharide (8.0-13.3% of dry alga weight) was alginic acid. Its content did not undergo significant changes from April to July. The content of water-soluble polysaccharides (laminarans and fucoidans) was low (<0.3% of dry alga weight). Water-soluble polysaccharides of the studied alga were practically pure fucoidan. The amount of laminarans was insignificant (<0.01% of dry alga weight). The content of fucoidans increased in alga samples from May through July. It was shown that P. pavonica is a promising source of alginic acids, which have a high capacity for gelation, and fucoidans, which exhibit antitumor action against RPMI-7951 human melanoma cells.     

Fucoidans from Brown Seaweeds <Emphasis Type="Italic">Sargassum hornery</Emphasis>, <Emphasis Type="Italic">Eclonia cava</Emphasis>, <Emphasis Type="Italic">Costaria costata</Emphasis>: Structural Characteristics and Anticancer Activity

Fucoidans were isolated by water extraction and ion-exchange chromatography from brown algae Eclonia cava, Sargassum hornery, and Costaria costata collected near of Korean coasts. The structures of fucoidans were investigated. Fucoidan from E. cava was mixture of sulfated rhamnogalactofucan and galactofucan. Fucoidan from C. costata was a sulfated galactofucan. Fucoidan isolated from S. hornery was separated into three fractions: a homofucan sulfate, a homofucan but without sulfate groups, and a sulfated rhamnofucan. The results clearly showed that fucoidans play an inhibitory role in colony formation in human melanoma and colon cancer cells and may be effective antitumor agents.     

Characteristics of polysaccharides and protein associated with them from dried and freshly collected red alga <Emphasis Type="Italic">Tichocarpus crinitus</Emphasis>

Polysaccharides isolated by successive extraction with water at 20 and 80°C from freshly collected and dried alga T. crinitus were compared. It was shown that the yield of polysaccharides from freshly collected alga was 40–44%; from dried material, less than 25%. It was found that the amount of extracted polysaccharides and their molecular weights decreased upon storage of dried alga for three years. Polysaccharides isolated from freshly collected and dried alga had identical structures and were a mixture of κ/β- and a new X-type of carrageenan. It was shown that protein, the amount of which reached 24% in the extracts obtained at 20°C, was strongly bound to the carrageenan. The amino-acid compositions of the proteins associated with the polysaccharides isolated at 20 and 80°C were identical and had an elevated content of serine, glutamic acid, glycine, and alanine.     

Chemical evaluation of seeded fruit biomass of oil pumpkin (<Emphasis Type="Italic">Cucurbita pepo</Emphasis> L. var. <Emphasis Type="Italic">Styriaca</Emphasis>)

Oil pumpkin (Cucurbita pepo L. var. Styriaca) is an economically important horticultural plant cultivated for oil production. After harvesting seeds, the residual biomass has a limited application and is usually left in the field. An experimental study was performed to evaluate the chemical composition of the seeded fruit oil pumpkin biomass (OP) dried by solvent-exchange using ethanol. The sugar composition of polysaccharides obtained by sequential extraction with water and dilute alkali indicated the prevalence of pectic polysaccharides. Hemicelulloses were released in higher amounts in the alkaline step. The chemical composition of OP and its individual tissues (peel, flesh and hairy flesh) was investigated and compared to the corresponding preparations of standard pumpkin (SP, Cucurbita pepo L.). The content of components (on oven-dry basis), calculated from the analysis data of the individual tissues, was estimated for OP: 7.9 % ash, 7.6 % Klason lignin, 19.3 % pectin (as uronic acids), 34.1 % neutral carbohydrates, and 27.4 % α-cellulose and for SP: 6.4 % ash, 4.0 % Klason lignin, 20.9% pectin (as uronic acids), 38.1% neutral carbohydrates, and 29.2 % α-cellulose, respectively. The OP biomass showed a higher proportion of hemicelluloses.     

Molecular properties of the copolymers of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-diallyl-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethylammonium chloride and maleic acid

The hydrodynamic and conformational properties of molecules of poly(N,N-diallyl-N,N-dimethylammonium chloride) and N,N-diallyl-N,N-dimethylammonium chloride-maleic acid copolymers of different compositions in solutions with various ionic-strength and pH values, as well as of the polyelectrolyte complex based on the copolymer with dodecyl sulfate anions in chloroform, are studied. For poly(N,N-diallyl-N,N-dimethylammonium chloride) molecules in a 1 M NaCl solution, the Kuhn segment length and the hydrodynamic diameter of the chain are estimated as A = 3.9 nm and d = 0.48 nm, respectively. In acidic solutions with pH 3.5, the copolymers demonstrate behavior typical for polyelectrolytes. In an alkaline solution with pH 13, when 1 M NaCl is added to the solution of the copolymer containing 29 mol % maleic acid units, there is an antipolyelectrolyte effect that manifests itself as an increase in the intrinsic viscosity of the copolymer and in the hydrodynamic radius of its molecules. It is found that an increase in the fraction of maleic acid units in the copolymer from 12 to 42 mol % brings about a reduction in the equilibrium rigidity of its macromolecules from 4.1 to 2.2 nm. The equilibrium rigidity of polyelectrolyte-complex molecules is higher than that of initial copolymer molecules owing to steric interactions arising between the aliphatic chains of dodecyl sulfate anions. In an electric field, the molecules of the complex are oriented owing to the induced dipole moment resulting from the displacement of dodecyl sulfate anions along the chain contour.     

Factors Affecting the Adsorption of Bacteriocins to <Emphasis Type="Italic">Lactobacillus sakei</Emphasis> and <Emphasis Type="Italic">Enterococcus</Emphasis> sp.

Bacteriocins bacJW3BZ and bacJW6BZ produced by Lactobacillus plantarum, and bacJW11BZ and bacJW15BZ produced by Lactobacillus fermentum, inhibit Gram-positive and Gram-negative bacteria. Treatment of Enterococcus sp. HKLHS and Lactobacillus sakei DSM 20017 with these bacteriocins deformed the cells and resulted in DNA and β-galactosidase leakage. The bacteriocins adsorbed to sensitive and resistant strains. Optimal adsorption of bacJW3BZ and bacJW6BZ to Enterococcus sp. HKLHS was recorded at pH 10.0, whereas adsorption of bacJW11BZ and bacJW15BZ was favored at pH 4.0–8.0 and 2.0–4.0, respectively. Adsorption to L. sakei DSM 20017 was less influenced by pH. Incubation temperature had a major influence on the adsorption of bacJW6BZ and bacJW11BZ to sensitive cells, with better results recorded below 30°C. Although variable results were recorded for bacJW3BZ and bacJW15BZ, optimal adsorption occurred between 37 and 60°C. Variable levels of adsorption were recorded in the presence of inorganic salts and solvents, and this seems to be species-specific. Maximal adsorption (100%) was recorded for bacJW3BZ and bacJW15BZ to L. sakei DSM 20017 in the presence of most inorganic salts and solvents tested. Maximal adsorption of bacJW6BZ to Enterococcus sp. HKLHS (50%) was recorded in the presence of Triton X-114 and little (17%) or no adsorption in the presence of other reagents.     

Culture of Microalgae <Emphasis Type="Italic">Chlamydomonas reinhardtii</Emphasis> in Wastewater for Biomass Feedstock Production

The objective of this research was to develop large-scale technologies to produce oil-rich algal biomass from wastewater. The experiments were conducted using Erlenmeyer flasks and biocoil photobioreactor. Chlamydomonas reinhardtii was grown in artificial media and wastewaters taken from three different stages of the treatment process, namely, influent, effluent, and centrate. Each of wastewaters contained different levels of nutrients. The specific growth rate of C. reinhardtii in different cultures was monitored over a period of 10 days. The biomass yield of microalgae and associated nitrogen and phosphorous removal were evaluated. Effects of CO₂ and pH on the growth were also studied. The level of nutrients greatly influenced algae growth. High levels of nutrients seem to inhibit algae growth in the beginning, but provided sustained growth to a high degree. The studies have shown that the optimal pH for C. reinhardtii is in the range of 7.5. An injection of air and a moderate amount of CO₂ promoted algae growth. However, too much CO₂ inhibited algae growth due to a significant decrease in pH. The experimental results showed that algal dry biomass yield reached a maximum of 2.0 g L⁻¹ day⁻¹ in the biocoil. The oil content of microalgae of C. reinhardtii was 25.25% (w/w) in dry biomass weight. In the biocoil, 55.8 mg nitrogen and 17.4 mg phosphorus per liter per day were effectively removed from the centrate wastewater. Ferric chloride was found to be an effective flocculent that helps the algae settle for easy harvest and separation from the culture media.     

Infrared spectroscopy study of <Emphasis Type="Italic">Gleditsia macracantha</Emphasis> seeds

Seeds of Gleditsia macracantha were shown to contain a protein—carbohydrate complex using IR spectroscopy. It was found that the carbohydrate composition was heterogeneous and included a neutral polysaccharide and a carboxypolysaccharide containing acetyl, ester, and ionized carboxylic groups.     

Chemical evaluation of <Emphasis Type="Italic">Fallopia</Emphasis> species leaves and antioxidant properties of their non-cellulosic polysaccharides

Utilization of biomass from forest or agricultural crops for the production of energy or chemical products provides environmental advantages. Leaves of the knotweeds Fallopia japonica, Fallopia sachalinensis, and Fallopia × bohemica are rich sources of phenolics and polysaccharides. In view of their potential utilization before the disposal of these invasive plants, their gross composition was investigated. The content of extractives was the highest in F. sachalinensis. Extractive-free leaves of all species showed similar chemical composition. The content of ash, protein, lignin, uronic acids, and α-cellulose in the leaves of F. sachalinensis, F. × bohemica, and F. japonica was 63.3 %, 64.1 %, and 63.4 %, respectively. The rest comprised hemicelluloses and neutral carbohydrate components of pectic polysaccharides. Sequential extraction of F. sachalinensis with water, EDTA, DMSO, 1 % NaOH, and 5 % NaOH yielded fractions accounting together for 27.6 % of polysaccharides. Pectic polysaccharides predominated in the first three fractions, whereas the hemicellulose components — xylan and xyloglucan, prevailed in the two alkaline fractions. The polysaccharides displayed significant radical scavenging activities in the 1,1-diphenyl-2-picrylhydrazyl free radical assay thus indicating their potential application as novel natural antioxidants.     

Screening and Immobilization <Emphasis Type="Italic">Burkholderia</Emphasis> sp. GXU56 Lipase for Enantioselective Resolution of (<Emphasis Type="Italic">R</Emphasis>,<Emphasis Type="Italic">S</Emphasis>)-Methyl Mandelate

Microorganisms producing lipase were isolated from soil and sewage samples and screened for enantioselective resolution of (R,S)-methyl mandelate to (R)-mandelic acid. A strain designated as GXU56 was obtained and identified as Burkholderia sp. Preparing immobilized GXU56 lipase by simple adsorption on octyl sepharose CL-4B, the optimum temperature was shifted from 40 °C (free lipase) to 50 °C (immobilized lipase), and the optimum pH was shifted from 8.0 (free lipase) to 7.2 (immobilized lipase). The immobilized enzyme displayed excellent stability in the pH range of 5.0–8.0, at the temperatures below 50 °C and in organic solvents compared with free enzyme. Enantioselectivity ratio for (R)-mandelic acid (E) was dramatically improved from 29.2 to more than 300 by applying immobilized lipase in the resolution of (R,S)-methyl mandelate. After five cycles of use of immobilized lipase, conversion and enantiomeric excess of (R)-mandelic acid were 34.5% and 98.5%, respectively, with enantioselectivity ratio for (R)-mandelic acid (E) of 230. Thus, octyl-sepharose-immobilized GXU56 lipase can be used as a bio-resolution reagent for producing (R)-mandelic acid.     

<Emphasis Type="Italic">Z</Emphasis>-and <Emphasis Type="Italic">E</Emphasis>-conformers of <Emphasis Type="Italic">N</Emphasis>-chloroacetylcytisine

N-Chloroacetylcytisine was synthesized by acylation of (–)-cytisine. Stable Z- and E-conformers with respect to rotational isomerism around the N-12–CO bond were found in PMR spectra at room temperature. The point at which PMR resonances of the Z- and E-conformers coalesced upon heating was measured. The transition barrier between the conformers was estimated.     

A new ten-membered lactone from <Emphasis Type="Italic">Tubercularia</Emphasis> sp<Emphasis Type="Italic">.</Emphasis> TF5, an endophytic fungus of <Emphasis Type="Italic">Taxus mairei</Emphasis>

One new ten-membered lactone (1) named (Z)-4,6,9-trihydroxy-10-nonyl-3,4,5,6,9,10-hexahydrooxecin-2-one along with 5-methoxycarbonylmellein (2) and cytochalasin D (3) were isolated from the culture of the endophytic fungus strain Tubercularia sp. TF5, originally separated from the inner bark of Taxus mairei obtained in Fujian Province, Southeast China. The structures of compounds 1–3 were elucidated by spectroscopic methods. The antimicrobial and cytotoxic activities of 1 were analyzed but it showed no significant activities.     

Phenylpropanoids and polysaccharides from <Emphasis Type="Italic">Plantago depressa</Emphasis> and <Emphasis Type="Italic">P. media</Emphasis> growing in Buryatia

The composition of phenylpropanoids and polysaccharides from leaves of Plantago depressa and P. media (Plantaginaceae) growing in Buryatia was studied. Caffeic and chlorogenic acids and acteoside were found in the studied plants; isoacteoside and plantamajoside, in P. media. The dominant compound in P. depressa was acteoside (8.72 mg/g); in P. media, plantamajoside (7.69 mg/g). These were responsible for the pronounced antiradical activity. Polysaccharide components that were extracted by water and an oxalate mixture were highly esterified pectinic substances with anti-atherogenic activity.     

Lipids from <Emphasis Type="Italic">Crambe amabilis</Emphasis> and <Emphasis Type="Italic">C. kotschyana</Emphasis> seeds grown with saline irrigation water

Lipids from Crambe amabilis Butk. et Majlun and C. kotschyana Boiss. grown in the open in Uzbekistan in soil imported from the Aral Sea region were studied. It was found that the seed oil content decreased with increasing salinity of irrigation water with EC 1.5 up to 9.0 dS/m. The content of polar lipids increased. The content of unsaturated acids from C. amabilis neutral lipids was 94.74–97.46%; C. kotschyana, 95.76– 96.78%.     

Lipids and flavolignans from <Emphasis Type="Italic">Silybum marianum</Emphasis>

Lipids from the air-dried aerial part (AP) and seeds of Silybum marianum (L.) Gaerth. (Asteraceae) were studied. The class and fatty acid compositions of neutral lipids (AP, seeds) and glyco- and phospholipids (AP) were determined. Neutral lipids (NL) with a complicated set of lipophilic components, mainly triterpenols, sterols, and their esters predominated in the AP. The fatty acids of the AP were dominated by 16:0, 18:2 (glycolipids), and 18:3 (neutral lipids, phospholipids); of seed NL, by 18:2 and 18:1. The content and composition of flavolignans isolated from defatted seeds and the content of total protein in the meal were found.     

Copolymer of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-diallyl-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethylammonium chloride with maleic acid as drug carrier

A copolymer of N,N-diallyl-N,N-dimethylammonium chloride with maleic acid of constant composition was prepared under the conditions of radical initiation. The possibility of the functionalization of the copolymer with drugs containing amino groups by polymer-analogous transformations was examined. Conditions were found for preparing conjugates of the copolymer with isoniazid. The structures and the quantitative compositions of the conjugates were determined by ¹³С NMR spectroscopy, and the possibility of preparing conjugates with controlled drug content was demonstrated.     

<Emphasis Type="Italic">Stachys lavandulifolia</Emphasis> and <Emphasis Type="Italic">Lathyrus</Emphasis> sp. Mediated for Green Synthesis of Silver Nanoparticles and Evaluation Its Antifungal Activity Against <Emphasis Type="Italic">Dothiorella sarmentorum</Emphasis>

In this study, silver nanoparticles (AgNPs) were biosynthesized using Stachys lavandulifolia and Lathyrus sp. The first sign of the reduction of silver ions to AgNPs was the change in color of S. lavandulifolia and Lathyrus sp. extracts changed into dark brown and auburn after treating with silver nitrate, respectively. The UV–Vis spectroscopy of reaction mixture (extract+silver nitrate) produced by S. lavandulifolia and Lathyrus sp. showed the strong adsorption peaks at ?440 and 420 nm, respectively. The transmission electron microscope images showed the synthesis of AgNPs using S. lavandulifolia and Lathyrus sp. with an average size of 7 and 11 nm, respectively. The result of X-ray diffraction pattern showed four diffraction peaks at 38°, 44°, 64°, and 77° for both types of biosynthesized AgNPs. Fourier transform infrared spectroscopy showed the possible role of involved proteins and polyhydroxyl functional groups in the synthesis process of AgNPs. Inductively coupled plasma analysis determined the conversion rate (percentage) of silver ions to silver nanoparticles in reaction mixtures of S. lavandulifolia and Lathyrus sp. 99.73 and 99.67 %, respectively. In addition, antifungal effect of AgNPs, synthesized by both extracts, was studied separately on mycelial growth of Dothiorella sarmentorum, in a completely randomized design on potato dextrose agar (PDA) medium. The inhibition rate of mycelial growth was strongly depended on the density of AgNPs and it strongly increased with increasing the density of AgNPs in the PDA medium. AgNPs more than 90 % of them inhibited from the mycelia growth of the fungus at the concentration of 40 µg/mL and higher.     

Arabinogalactomannan from <Emphasis Type="Italic">Gleditsia macracantha</Emphasis> seeds

A polysaccharide with MW 25,000 consisting of arabinose, galactose, and mannose units in a 1:2.8:3.2 ratio was isolated from Gleditsia macracantha seeds. Chemical and spectral methods established that the polysaccharide was a branched galactomannan with side branches consisting of arabinose units. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 128-130, March-April, 2009.     

Lipids from <Emphasis Type="Italic">Halostachys caspica</Emphasis> and <Emphasis Type="Italic">Halocharis hispida</Emphasis>

The composition of lipids from the aerial parts of two species of halophytes from the family Chenopodiaceae, Halostachys caspica C. A. Mey. and Halocharis hispida Bge. was determined. Neutral lipids (NL, 62.1 and 54.2%, respectively) dominated the total lipids (TL) of these plants. More than a third of the NL were esters of aliphatic alcohols and phytosterols (FAE). Fatty acids 16:0, 18:1, and 18:2 dominated the acids of FAE; 16:0, 18:1, and 18:3, the phospholipids. The principal fatty acids of glycolipids were unsaturated acids (68.3 and 75.1%) with linolenic acid dominating (44.9 and 43.5%). Presented at the 7th International Symposium on the Chemistry of Natural Compounds, Tashkent, October 16–18, 2007. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 276–278, May–June, 2009.     

Determination of epoxides by high-performance liquid chromatography following derivatization with <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-diethyldithiocarbamate

A reversed-phase, high-performance liquid chromatography (RP-HPLC) method that allows quantitation of low levels of epoxides has been described. The method involved derivatization of epoxides using 100- to 1,000-fold excess N,N-diethyldithiocarbamate (DTC) at 60 °C for 20 min at neutral pH. The unreacted DTC was then decomposed to CS₂ and diethyl amine by acidification of the reaction mixture to pH 2 using orthophosphoric acid. The first two steps could be performed in the same reaction vessel by sequential addition of reagents. In the final step, an aliquot (20 μL) of the derivatized sample was analyzed for the presence of stable esters of DTC by RP-HPLC using a Supelcosil LC-18-S (150 × 4.6-mm) column and a mobile phase consisting of 40% (v/v) acetonitrile in water at a flow of 1 mL min⁻¹. Using UV detection at 278 nm, the epoxides gave linear responses in the concentration range of 0.25 to 50 μM. The method is robust, and as low as 5 pmol of the analyte could be successfully detected and quantified with recoveries of ≥94%. Following a minimal pretreatment such as ultrafiltration (molecular weight cutoff 5,000 Da), the method is suitable for analysis of epoxides in complex physiological fluids (e.g., fetal bovine serum). The method has been rigorously evaluated and adapted in our laboratory for routine analysis and determination of stability of epoxides of 1,3-butadiene and other alkenes added to cell cultures.