Pectic Polysaccharides Research Articles

Physicochemical characterization, antioxidant capacity, total phenolic and proanthocyanidin content of flours prepared from pequi (Caryocar brasilense Camb.) fruit by-products

The potential of pequi by-products as substrates for the production of flours rich in antioxidant dietary fibers was evaluated. Dietary fiber contents ranged from 39.8 to 43.3g/100g with pectic polysaccharide fraction constituted of rhamnogalacturonans and hemicellulose fraction consisted of arabinogalactans, xylans and glucomannans. Total polyphenols, non-extractable proanthocyanidins (NEPA) and carotenoid contents of the flours were determined (respectively, 15.5-17.4g GAE/100g, 215.54-346.84mg/100g and 2116.52-3499.03μg/100g). The antioxidant capacities of pequi by-product flours (986.94-1154.42μM TE/g ABTS; 44.43-48.02g/g DPPH; and 3027.31-3216.27μmol Fe2SO4/g FRAP) were found to be exceptionally higher than those of fruits and fruits by-products reported in the literature. Exocarp removal promoted no significant changes in the technological properties of the flour, except for color. Results showed promising prospects for future exploitation of pequi peel as a potential source of dietary fiber and natural antioxidants.

Эффективность обработки картофеля пектиновыми полисахаридами

The article presents research materials for 2012...2015 on the study of the influence of new growth regulators on precocity, productivity and quality of potato tubers cultivated on sod-podzolic soil in the conditions of the Republic of Komi. Object of research - zoned varieties of potato Nevsky (middle-early) and Gloria (early-ripe). Biopreparation Verva and new pectic polysaccharides Lemnan (LM) - pectin from Lemna minor L. and Silenan (SV) - pectin from callus tissue of Silene vulgaris (M.) G. [Oberna behen (L.) Ikonn] were tested as the growth regulators The experiment scheme included pre-sowing soaking of potato tubers (dilution rate - 100 ml per 10 liters of water, consumption - 10 liters per 1 ton of tubers) and top-dressing of plants at phases of 3.5 leaves and tuber formation (dilution rate - 100 ml per 10 liters of water, consumption of working liquid - 300 liters/ha). Pre-sowing treatment and top-dressing with water was used as control. The use of pectic polysaccharides accelerated the passage of the development phases of potato varieties: the period of emergence of full shoots - by 2.8 days; from shoots to budding - by 2.7 days, from budding to mass flowering - by 4.14 days. Preparations LM, SV, Verva increased the early potato productivity by 51.2; 32.5; 48.8% (variety Nevsky) and 220.5; 261.4; 245.5% (variety Gloria) in comparison with the control variant. The increments of the total yield were according in variety Nevsky 9.3; 7.3; 8.9 t/ha (38.0.48.4%), in variety Gloria 32.7; 23.7; 29.9 t/ha (106.3.146.6%). Treatment with pectic polysaccharides increased the content of dry matter, starch, and vitamin C in tubers of potato respectively by 1.6.2.4; 5.1.6.2; 3.2.3.7% in variety Nevsky, and by 12.1.14.9; 13.1.17.2; 25.7.32.4% in variety Gloria. The use of preparations LM and SV reduced the nitrate content in tubers by 8.22 mg/kg (variety Nevsky) and 83.71 mg/kg (variety Gloria).

Эффективность обработки картофеля пектиновыми полисахаридами

The article presents research materials for 2012...2015 on the study of the influence of new growth regulators on precocity, productivity and quality of potato tubers cultivated on sod-podzolic soil in the conditions of the Republic of Komi. Object of research - zoned varieties of potato Nevsky (middle-early) and Gloria (early-ripe). Biopreparation Verva and new pectic polysaccharides Lemnan (LM) - pectin from Lemna minor L. and Silenan (SV) - pectin from callus tissue of Silene vulgaris (M.) G. [Oberna behen (L.) Ikonn] were tested as the growth regulators The experiment scheme included pre-sowing soaking of potato tubers (dilution rate - 100 ml per 10 liters of water, consumption - 10 liters per 1 ton of tubers) and top-dressing of plants at phases of 3.5 leaves and tuber formation (dilution rate - 100 ml per 10 liters of water, consumption of working liquid - 300 liters/ha). Pre-sowing treatment and top-dressing with water was used as control. The use of pectic polysaccharides accelerated the passage of the development phases of potato varieties: the period of emergence of full shoots - by 2.8 days; from shoots to budding - by 2.7 days, from budding to mass flowering - by 4.14 days. Preparations LM, SV, Verva increased the early potato productivity by 51.2; 32.5; 48.8% (variety Nevsky) and 220.5; 261.4; 245.5% (variety Gloria) in comparison with the control variant. The increments of the total yield were according in variety Nevsky 9.3; 7.3; 8.9 t/ha (38.0.48.4%), in variety Gloria 32.7; 23.7; 29.9 t/ha (106.3.146.6%). Treatment with pectic polysaccharides increased the content of dry matter, starch, and vitamin C in tubers of potato respectively by 1.6.2.4; 5.1.6.2; 3.2.3.7% in variety Nevsky, and by 12.1.14.9; 13.1.17.2; 25.7.32.4% in variety Gloria. The use of preparations LM and SV reduced the nitrate content in tubers by 8.22 mg/kg (variety Nevsky) and 83.71 mg/kg (variety Gloria).

The Antioxidant Properties of Pectin Fractions Isolated from Vegetables Using a Simulated Gastric Fluid

The antioxidant properties of vegetable pectin fractions against intraluminal reactive oxygen species were elucidated in vitro in conjunction with their structural features. The pectin fractions were isolated using a simulated gastric fluid (pH 1.5, pepsin 0.5 g/L, 37°C, 4 h) from fresh white cabbage, carrot, onion, and sweet pepper. The fraction from onion was found to inhibit the production of superoxide radicals by inhibiting the xanthine oxidase. The high molecular weight of onion pectin and a large number of galactose residues in its side chains appeared to participate in interaction with xanthine oxidase. All the isolated pectic polysaccharides were found to be associated with protein (2–9%) and phenolics (0.5–0.7%) as contaminants; these contaminants were shown to be responsible for the antioxidant effect of vegetable pectin fractions against the hydroxyl and 1,1-diphenyl-2-picrylhydrazyl radicals.

Green recovery of pectic polysaccharides from citrus canning processing water

Canned citrus segments are popularly consumed worldwide with a large global market. However, the production needs chemical treatment to remove segments membranes, producing a large amount of acidic and basic effluents with very high chemical oxygen demand (COD), causing serious environmental problems. This research is focused on the plant scale recovery of pectic polysaccharides from the above acidic and basic processing water to decrease COD and develop a new product, through steps including water reuse (alternative), two-step filtration, concentration, ethanol precipitation and ethanol recovery. The yields of polysaccharides were 0.30% and 0.45% (w/v) from reused acidic and basic water, respectively, dramatically decreasing the COD by ∼75% from ∼10,000 mg/L, and having a great estimated output value of ∼$1.8 million annually for each factory. Polysaccharides from acidic water mainly contains homogalacturonan regions with ∼50% degree of esterification, whereas that from basic water was dominated with rhamnogalacturonan I regions with almost no esterification. The high viscosity of these branching polysaccharides, combined with gelling experiment results, suggested that both polysaccharides might be potential food thickening and gelling agents with large benefits to both the environment and the economy.

Pectic Oligosaccharide from tomato exhibiting anticancer potential on a gastric cancer cell line: Structure-function relationship

Pectic Polysaccharide (PP) from dietary sources has been known to prevent cancer growth and hence impede cancer progression. We evaluated anticancer effect of Pectic-Oligosaccharide isolated from Sour Raw Tomato (SrTPO); its bioavailability and structure elucidated from purified fraction (SrTPO1). SrTPO1 inhibited galectin-3 activity with MIC of 0.25 ug/mL (100 fold better than standard galactose), inhibited the growth of AGS cells (IC50 3.4μg/mL) and induced apoptosis (70% inhibition at 30μg/mL concentration). Normal– NIH 3T3 cells were not affected by SrTPO as opposed to doxorubicin, a known anticancer drug, which reduced 76% viability at equivalent dose. SrTPO1 was identified as RhamnogalacturonanI-arabinogalactan (RGI-AG), where repeated alternative rhamnose and galacturonic acid residues were observed while arabinose in the branch point and β-1,4 linked galactose in the linear chain form. SrTPO was found to be bioavailable as evaluated by FITC labelled oligos inside the cell, which was in reciprocal proportion with apoptosis.

Identification of a Novel L-rhamnose Uptake Transporter in the Filamentous Fungus Aspergillus niger.

The study of plant biomass utilization by fungi is a research field of great interest due to its many implications in ecology, agriculture and biotechnology. Most of the efforts done to increase the understanding of the use of plant cell walls by fungi have been focused on the degradation of cellulose and hemicellulose, and transport and metabolism of their constituent monosaccharides. Pectin is another important constituent of plant cell walls, but has received less attention. In relation to the uptake of pectic building blocks, fungal transporters for the uptake of galacturonic acid recently have been reported in Aspergillus niger and Neurospora crassa. However, not a single L-rhamnose (6-deoxy-L-mannose) transporter has been identified yet in fungi or in other eukaryotic organisms. L-rhamnose is a deoxy-sugar present in plant cell wall pectic polysaccharides (mainly rhamnogalacturonan I and rhamnogalacturonan II), but is also found in diverse plant secondary metabolites (e.g. anthocyanins, flavonoids and triterpenoids), in the green seaweed sulfated polysaccharide ulvan, and in glycan structures from viruses and bacteria. Here, a comparative plasmalemma proteomic analysis was used to identify candidate L-rhamnose transporters in A. niger. Further analysis was focused on protein ID 1119135 (RhtA) (JGI A. niger ATCC 1015 genome database). RhtA was classified as a Family 7 Fucose: H+ Symporter (FHS) within the Major Facilitator Superfamily. Family 7 currently includes exclusively bacterial transporters able to use different sugars. Strong indications for its role in L-rhamnose transport were obtained by functional complementation of the Saccharomyces cerevisiae EBY.VW.4000 strain in growth studies with a range of potential substrates. Biochemical analysis using L-[3H(G)]-rhamnose confirmed that RhtA is a L-rhamnose transporter. The RhtA gene is located in tandem with a hypothetical alpha-L-rhamnosidase gene (rhaB). Transcriptional analysis of rhtA and rhaB confirmed that both genes have a coordinated expression, being strongly and specifically induced by L-rhamnose, and controlled by RhaR, a transcriptional regulator involved in the release and catabolism of the methyl-pentose. RhtA is the first eukaryotic L-rhamnose transporter identified and functionally validated to date.

β-Glucans and Resistant Starch Alter the Fermentation of Recalcitrant Fibers in Growing Pigs.

Interactions among dietary ingredients are often assumed non-existent when evaluating the nutritive value and health effects of dietary fiber. Specific fibers can distinctly affect digestive processes; therefore, digestibility and fermentability of the complete diet may depend on fiber types present. This study aimed to evaluate the effects of readily fermentable fibers (β-glucans and resistant starch) on the degradation of feed ingredients containing more persistent, recalcitrant, fibers. Six semi-synthetic diets with recalcitrant fibers from rapeseed meal (pectic polysaccharides, xyloglucans, and cellulose) or corn distillers dried grain with solubles (DDGS; (glucurono)arabinoxylans and cellulose) with or without inclusion of β-glucans (6%) or retrograded tapioca (40%) substituted for corn starch were formulated. Six ileal-cannulated pigs (BW 28±1.4 kg) were assigned to the diets according to a 6×6 Latin square. β-glucan-extract increased apparent total tract digestibility (ATTD) of non-glucosyl polysaccharides (accounting for ~40% of the fiber-fraction) from rapeseed meal (6%-units, P<0.001), but did not affect non-glucosyl polysaccharides from DDGS. Retrograded tapioca reduced ATTD of non-glucosyl polysaccharides from rapeseed meal and DDGS (>10%-units, P<0.001), indicating that the large amount of resistant starch entering the hindgut was preferentially degraded over recalcitrant fibers from rapeseed meal and DDGS, possibly related to reduced hindgut-retention time following the increased intestinal bulk. Fermentation of fiber sources was not only dependent on fiber characteristics, but also on the presence of other fibers in the diet. Hence, interactions in the gastrointestinal tract among fibrous feed ingredients should be considered when evaluating their nutritive value.

Extraction and characterization of pectins from primary cell walls of edible açaí (Euterpe oleraceae) berries, fruits of a monocotyledon palm

Açaí berries (Euterpe oleracea) are greatly consumed in Brazil and exported to other countries as a nutritional supplement, due to health benefits attributed to its consumption. However, the complete chemical structure of bioactive polysaccharides was not fully elucidated yet. In this work, we characterize pectic polysaccharides from açaí berries through monosaccharide composition, HPSEC, methylation and 13C and 1H/13C HSQC-DEPT-NMR analyses. A highly methoxylated homogalacturonan with a DM of 88% and Mw of 22kDa together with small amounts of a mannoglucan were found. Moreover, a type II arabinogalactan (Mw=45kDa) containing a backbone with high portions of 6-O-linked and 3,6-O-linked Galp chains rather than 3-O-linked Galp was also isolated and structurally characterized. The type II arabinogalactan was found as a side chain of a type I rhamnogalacturonan. These findings contribute to correlate the fine chemical structure with the previously reported action of açaí polysaccharides on innate immune response. Moreover, from the taxonomic point of view, the results bring new information about polysaccharide composition of primary cell walls of palms (Arecaceae), that despite being commelinid monocots, have a distinct cell wall composition.

Understanding of plant cell wall biosynthesis for utilization of lignocellulosic biomass resources

How do plants make cell walls? How can the cell wall biomass be turned into fuel energy? These questions are still unsolved puzzles that have attracted a great deal of interest in scientific community as well as in industrial and political worlds. Different from animal cells, plant cells develop characteristic structures of cell walls, which play crucial roles in planting growth and response to environments. As cell walls accumulate approximately seventy percent of the land pant photosynthesized products on the globe, cell wall biomass is the most abundant renewable resource for production of bioenergy and biomaterials. However, only a small portion (~2%) of the plant cell wall resource has been used by human society so far. More efficient utilization of lignocellulosic cell wall biomass is highly desired. Great effort has been invested in understanding of how cell walls are formed in plant in recent years. Plants cell walls contain cellulose, hemicelluloses, pectic polysaccharides and lignin. These polysaccharides and phenolic polymers are constructed in concrete cell walls for supporting plant growth and development. Cellulose is composed of β-1,4-linked glucose units and a bundle of multiple -1,4-glucan chains together form microfibrils, providing a skeleton of cell wall structures. Cellulose is synthesized in plants by cellulose synthase (CesA) complexes which are integrated and localized in plasma membrane. There are a family of CesA genes in plants which direct cellulose synthesis in different layer of cell walls or regulate cellulose microfibril structures. Although cellulose has been used in many aspects of human life, such as fiber cloth, paper, and modified cellulosic products, Cellulose, the most abundant biopolymer on the Earth, promises more utilization in supporting for sustainability of human society development. Hemicellulose is a group of diverse polysaccharides, such as xyloglucan, heteromannans, heteroxylans and mixed- linkage glucan. Their diverse structure and sugar composition varies in plant species, tissues, even cell types. Hemicellulose polysaccharides, amorphous and soluble in aqueous solutions, are composed of heterogeneous monosaccharide units or linkages in their backbone and branched side chains. Hemicelluloses are usually covalently linked to cellulose and lignin in cell wall matrix. Hemicellulose has been used in many applications such as food products and nutritional supplements. How is hemicellulose synthesized? How do the diverse hemicelluloses function in plant development? How can the abundant hemicellulose sugars be used? Many questions remain to be investigated. Lignin is polymerized from phenolic monolignols and mainly deposited in the secondary cell walls of vascular plants. Evolved in higher plants, lignin is essential for long distance water transport, mechanical support of up-growth, pathogen defense and for other stress responses. In the cell walls, lignin is usually cross-linked with cellulose and hemicellulose. Although biosynthesis of monolignols including p-hydroxyphenyl (H), guaiacyl (G) and syringyl (S) monolignols has been elucidated genetically and biochemically in various plant species, regulation of monolignol formation in different species, tissues and cell types is still unclear. As the second most abundant plant biopolymer after cellulose on the globe, utilization of lignin is highly attended. Lignin is considered as a main recalcitrance during cell wall biomass conversion, therefore modification of lignin biosynthesis is of great interest in engineering plant cell walls for efficient biomass utilization. Laboratory research has showed potential benefits of lignin engineering for lignocellulosic biomass conversion, while application of the technology in the field requires more evaluation. This review summarizes recent studies of the biosynthesis of plant cell wall components such as cellulose, hemicelluloses and lignin as well as the modification of cell walls for the improvement of lignocellulosic biomass utilization.

A pectic polysaccharide from peach palm fruits (Bactris gasipaes) and its fermentation profile by the human gut microbiota in vitro

Depending on their chemical structure, pectic polymers may be fermented by different bacteria in the human gut and, therefore, display a different metabolite profile. We aimed to investigate the chemical structure of pectins from peach palm fruits and to evaluate their in vitro fecal fermentation profiles. A fraction (PW-AP) containing a linear highly methyl esterified homogalacturonan (degree of esterification of 70%) with minor portions of xylogalacturonan and type I rhamnogalacturonan was submitted to fermentation by the human gut microbiota. It produced significantly less gas than fructooligosaccharides (FOS) at all evaluated time points, and in 24h presented a cumulative gas production ~27% lower than FOS. Drops in pH could be observed during fermentation of both FOS and PW-AP. Moreover, the pectin was slower fermented than FOS, though with a similar production of total short chain fatty acids (SCFA) and a lower production of branched chain fatty acids. The amounts of specific SCFA differed from that of FOS, with higher production of acetate (16.2%) and propionate (6.2%) and lower production butyrate (112%). The ratio of total SCFA production to gas production was 4.0mL/µmol and 5.5mL/µmol for FOS and PW-AP, respectively, indicating that the latter leads to less gas formation per µmol of produced SCFA. Overall, the understanding of how pectic structures are fermented brings new insights into the fiber utilization by the human gut microbiota and its relation to biological outcomes.

KNS4/UPEX1: A Type II Arabinogalactan β-(1,3)-Galactosyltransferase Required for Pollen Exine Development.

Pollen exine is essential for protection from the environment of the male gametes of seed-producing plants, but its assembly and composition remain poorly understood. We previously characterized Arabidopsis (Arabidopsis thaliana) mutants with abnormal pollen exine structure and morphology that we named kaonashi (kns). Here we describe the identification of the causal gene of kns4 that was found to be a member of the CAZy glycosyltransferase 31 gene family, identical to UNEVEN PATTERN OF EXINE1, and the biochemical characterization of the encoded protein. The characteristic exine phenotype in the kns4 mutant is related to an abnormality of the primexine matrix laid on the surface of developing microspores. Using light microscopy with a combination of type II arabinogalactan (AG) antibodies and staining with the arabinogalactan-protein (AGP)-specific β-Glc Yariv reagent, we show that the levels of AGPs in the kns4 microspore primexine are considerably diminished, and their location differs from that of wild type, as does the distribution of pectin labeling. Furthermore, kns4 mutants exhibit reduced fertility as indicated by shorter fruit lengths and lower seed set compared to the wild type, confirming that KNS4 is critical for pollen viability and development. KNS4 was heterologously expressed in Nicotiana benthamiana, and was shown to possess β-(1,3)-galactosyltransferase activity responsible for the synthesis of AG glycans that are present on both AGPs and/or the pectic polysaccharide rhamnogalacturonan I. These data demonstrate that defects in AGP/pectic glycans, caused by disruption of KNS4 function, impact pollen development and viability in Arabidopsis.

Seasonal dynamics of polysaccharides in Norway spruce (Picea abies)

Annual dynamics of accumulation and changes in the monosaccharide composition of pectin-, arabinan- and galactan-containing polysaccharides and binding glycans isolated from greenery (thin branches with needles) of Norway spruce were investigated in this study. The polysaccharides were compared with polysaccharides of Siberian fir according to the yields, composition and content of typical components. It was shown that Norway spruce greenery contains lowly methyl-esterified pectin extracted with ammonium oxalate, which is a part of protopectic complex and is bound with components of cell walls via ionic bonds. In contrast, Siberian fir greenery contains mainly water-extracted highly methyl-esterified pectin, weakly bound to cell wall components. It was concluded that an autumn-winter period is the optimal time for harvesting Norway spruce and Siberian fir greenery for isolation of the pectic polysaccharides. The revealed regularities indicate that there is a certain biorhythm of accumulation of the compounds, probably determined by genetic factors.

Proton-conducting biopolymer electrolytes based on pectin doped with NH4X (X=Cl, Br)

Research has been undertaken to develop polymer electrolytes based on biodegradable natural polymers such as cellulose acetate, starch, gelatin, and chitosan, which are being used as polymer hosts for obtaining new polymer electrolytes for their applications in various electrochemical devices such as batteries, sensors, and electrochromic windows. Pectin is a naturally available material which is extracted from the skin of citrus fruits. Pectins, also known as pectic polysaccharides, are rich in galacturonic acid. The present study focuses on the proton-conducting polymer electrolytes based on the biopolymer pectin doped with ammonium chloride (NH4Cl) and ammonium bromide (NH4Br) prepared by solution casting technique. The prepared membranes are characterized using XRD, FTIR, and AC impedance techniques to study their complexation behavior, amorphous nature, and electrical properties. The conductivity of pure pectin membrane has been found to be 9.41 × 10−7 S cm−1. The polymer systems with 30 mol% NH4Cl-doped pectin and 40 mol% NH4Br-doped pectin have been found to have maximum ionic conductivity of 4.52 × 10−4 and 1.07 × 10−3 S cm−1, respectively. The conductivity value has increased by three orders of magnitude compared to pure pectin membrane. The dielectric behavior of both the systems has been explained using dielectric permittivity and electric modulus spectra.

Effect of Ethanol Addition on Subcritical Water Extraction of Pectic Polysaccharides from Passion Fruit Peel

The effect of ethanol addition (0 − 30% v/v) on subcritical water extraction (SCWE) of pectic polysaccharides from passion fruit peel was investigated. The peel was extracted in a batch-type reactor at the treatment temperatures range of 100 − 160C. As a result, low molecular weight pectic polysaccharides in a range of 15.4 − 38.5 kDa were obtained. Higher treatment temperatures tended to give higher yields while the addition of ethanol gave adverse effect, except for adding small amount at high temperatures. The maximum yield (12.28% dry matter basis) was obtained from the treatment at 140C using 10% ethanol. The major composition of extracted pectic polysaccharides was galacturonic acid (72.11 − 94.76%). Additionally, this study demonstrated that the addition of ethanol resulted in pectic polysaccharides that possessed higher 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and total phenolic content (TPC). Practical Applications Subcritical water extraction (SCWE) is an environmentally friendly method that can be used for extraction of pectic polysaccharides from passion fruit peel, which is a major waste from juice production. Addition of ethanol was successful to enhance the extractability of some bioactive compounds in the peel and resulted in pectic polysaccharides with higher total phenolic content (TPC) and free radical scavenging activity, which might be useful as functional food ingredients.

Revelation of β-sitosterol from Benincasa hispida Seeds, Carissa congesta Roots and Polyalthia longifolia Leaves by High Performance Liquid Chromatography

Background: Fruit juice of Benincasa hispida (BH) is regarded as Vrindamadhava that is recommended for internal use in snake’s bites. The fruits have been reported to contain good amount of proteins, enzymes, Vitamin B1 and C1 flavonoid C-glycoside, terpenes, phenolic acids and free sugars such as glucose, rhamnose, mannitol, uronic acid, astilbin, catechin, naringenin, pectic polysaccharides and even some trace metals. Polyalthia longifolia (PL) has been well known for its ayurvedic preparations such as Sitaphala kula, Kaphapitashama, Anulomak and Krimighna. PL leaves has been reported to contain phytoconstituents like polylongine, Aporphine-Noxide alkaloids, allo-aromadendrene, caryophyllene oxide, β-caryophyllene, β-selinene, α-humulene, α-pinene and camphene. Carissa congesta (CC), known as Bengal currant, have yielded 2-acetyl phenol, carissone, carindone and Des-n-methylnoracronycine. β-sitosterol, an important phytoconstituent recognized from all these selected plants has been well known for its ethnopharmacological importance. In this new study, the research team members has focused on determining the percentage of the β-sitosterol present in the BH seeds, CC roots and PL leaves by subjecting the extract to High Performance Liquid Chromatography (HPLC). Materials and Methods: BH, CC and PL plants were shade-dried and extracted by suitable extraction methods. In HPLC, peaks obtained in the extracts were compared with the standard by matching their retention time. Results: The amounts of β-sitosterol present in the BH seeds, CC roots and PL leaves extracts obtained at 254 nm were found to be 36.00, 7.46 and 3.21% w/w respectively. Conclusion: Thus, BH, PL and CC extracts were said to contain β-sitosterol as a key constituent.

Functional Characterization of UDP-apiose Synthases from Bryophytes and Green Algae Provides Insight into the Appearance of Apiose-containing Glycans during Plant Evolution

Apiose is a branched monosaccharide that is present in the cell wall pectic polysaccharides rhamnogalacturonan II and apiogalacturonan and in numerous plant secondary metabolites. These apiose-containing glycans are synthesized using UDP-apiose as the donor. UDP-apiose (UDP-Api) together with UDP-xylose is formed from UDP-glucuronic acid (UDP-GlcA) by UDP-Api synthase (UAS). It was hypothesized that the ability to form Api distinguishes vascular plants from the avascular plants and green algae. UAS from several dicotyledonous plants has been characterized; however, it is not known if avascular plants or green algae produce this enzyme. Here we report the identification and functional characterization of UAS homologs from avascular plants (mosses, liverwort, and hornwort), from streptophyte green algae, and from a monocot (duckweed). The recombinant UAS homologs all form UDP-Api from UDP-glucuronic acid albeit in different amounts. Apiose was detected in aqueous methanolic extracts of these plants. Apiose was detected in duckweed cell walls but not in the walls of the avascular plants and algae. Overexpressing duckweed UAS in the moss Physcomitrella patens led to an increase in the amounts of aqueous methanol-acetonitrile-soluble apiose but did not result in discernible amounts of cell wall-associated apiose. Thus, bryophytes and algae likely lack the glycosyltransferase machinery required to synthesize apiose-containing cell wall glycans. Nevertheless, these plants may have the ability to form apiosylated secondary metabolites. Our data are the first to provide evidence that the ability to form apiose existed prior to the appearance of rhamnogalacturonan II and apiogalacturonan and provide new insights into the evolution of apiose-containing glycans.

In vitro macrophage nitric oxide production by Pterospartum tridentatum (L.) Willk. inflorescence polysaccharides

Pterospartum tridentatum (L.) Willk. decoctions of dried inflorescences are used in Portugal due to their claimed beneficial properties for various health disorders. To disclose the potential contribution of its polysaccharides to health benefits, in this work, hot water extracts from P. tridentatum inflorescences were prepared and fractionated by ethanol precipitation and anion exchange chromatography. The fraction rich in acetylated galactomannans evidenced an increase in nitric oxide (NO) production by macrophages. This activity decreased 60–75% after saponification, confirming that acetylation is an important structural feature for this biological property. In addition, the treatment of pectic polysaccharides with endo-polygalacturonase showed that type-I and type-II arabinogalactans, as well as low molecular weight galacturonans and xyloglucans, may also contribute to macrophage NO production. Thus, the polysaccharides present in P. tridentatum dried inflorescences may contribute to the health beneficial properties frequently attributed to the decoctions of this plant.

Draft genome sequence of pectic polysaccharide-degrading moderate thermophilic bacterium Geobacillus thermodenitrificans DSM 101594.

Geobacillus thermodenitrificans DSM 101594 was isolated as a producer of extracellular thermostable pectic polysaccharide degrading enzymes. The completely sequenced genome was 3.6 Mb in length with GC content of 48.86%. A number of genes encoding enzymatic active against the high molecular weight polysaccharides of potential biotechnological importance were identified in the genome.

Detection of Inulin, a Prebiotic Polysaccharide, in Maple Syrup.

Maple syrup is a widely consumed plant-derived natural sweetener produced by concentrating xylem sap collected from certain maple (Acer) species. During thermal evaporation of water, natural phytochemical components are concentrated in maple syrup. The polymeric components from maple syrup were isolated by ethanol precipitation, dialysis, and anion exchange chromatography and structurally characterized by glycosyl composition analysis, glycosyl linkage analysis, and nuclear magnetic resonance spectroscopy. Among the maple syrup polysaccharides, one neutral polysaccharide was characterized as inulin with a broad molecular weight distribution, representing the first isolation of this prebiotic carbohydrate from a xylem sap. In addition, two acidic polysaccharides with structural similarity were identified as arabinogalactans derived from rhamnogalacturonan type I pectic polysaccharides.