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To evaluate the seeded fruit biomass of the Styrian oil-pumpkin in view of its pectin component, a series of acidic polysaccharides were isolated by a six-step sequential extraction using hot water, EDTA, dilute HCl (twice) and dilute and stronger NaOH solutions. Chemical, physicochemical and spectroscopy analyses revealed that the first four fractions comprised partially methyl-esterified and acetylated pectins with varying proportions of rhamnogalacturonan regions ramified with galactose- and arabinose-containing side chains and showed considerable polymolecularity. The alkali-extracted polysaccharides contained lower amounts of pectins with homogalacturonan and arabinose-rich rhamnogalacturonan regions next to hemicelluloses prevailing in the last polysaccharide. Using (1)H-(13)C HSQC and HMBC spectroscopy, the resonances of free and methylesterified galacturonic acid residues in the purified acid-extracted pectin were unambiguously established and various diads formed by both residues identified. The results might serve as a basis for searching technological conditions to produce pectin from the oil-pumpkin fruit biomass., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Several water-soluble pectic polysaccharides were isolated from the pumpkin fruit biomass and characterized by composition, structural features and molecular properties. The pectic polysaccharides were tested for antitussive activity by studying the effects of citric acid-induced cough reflex in guinea pigs and reactivity of the airway smooth muscle in vivo conditions in comparison to the narcotic drug codeine. Oral administration of all pectic polysaccharides from pumpkin inhibited the number of coughs induced by citric acid in guinea pigs, but to various extents. The results indicated that the antitussive activity of the pectic polysaccharides is affected by their molecular and structural properties, whereby a synergistic action between the polysaccharide and non-carbohydrate components on the biological response has been suggested as well. The cough depressive efficacy of most of the tested polysaccharides was comparable and even higher than that of codeine. Moreover, the application of these polysaccharides provoked any side effects what is their advantage towards the conventional opioid-derived antitussive agents., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Highlights • The hazelnut skin polysaccharides were identified by FTIR and NMR. • The unsaturated galacturonic acid confirmed the pectin degradation during roasting. • Methylesterified pectin and arabinan were dominant in the water fraction. • Deesterified pectin, arabinan and xylans formed the alkali fraction. Abstract Two polysaccharide fractions sequentially extracted with water 1W and alkali 1A, were isolated from the hazelnut skins. The monosaccharide composition together with the FTIR and NMR analyses, indicated that both fractions are formed from a mixture of polysaccharides. The fraction 1W consists of methyl-esterified pectic polysaccharide with rhamnogalacturonan I blocks, branching with arabinose side chains, and with 1,5-, 1,3,5-arabinan and galactan polysaccharides. The fraction 1A is a mixture of deesterified rhamnogalacturonan I and 1,5-, 1,3,5-arabinan and 4- O -Me-glucuronoxylan polysaccharides. The presence of unsaturated galacturonic acid and the heterogeneity of the molecular weights, which M w ranged between 3.6 and 39 kg mol−1, indicated the pectin degradation during roasting. [ABSTRACT FROM AUTHOR]

Highlights: [•] Pre-extracted Impatiens parviflora DC. leaves were subjected to five-step extraction. [•] The methanol extract contains caffeic acid, ferulic acid, and kaempferol derivatives. [•] Several non-cellulosic polysaccharides and phenolics were isolated. [•] A low methoxyl pectin and β-1,4-galactan were extracted by EDTA. [•] Methylglucuronoxylan and 3,6-arabinogalactan were isolated by 5% NaOH. [Copyright &y& Elsevier]

Abstract: Seeded fruit of oil pumpkin (Cucurbita pepo L. var. Styriaca) represents a rich source of pectic polysaccharides. Pectic polysaccharides were isolated by a three-step extraction procedure at various reaction conditions, where 0.01M ethylendiaminotetraacetic acid was used as extractant in the first step and 1% and 5% NaOH in the second and third steps. A classical extraction procedure (60min) or and two procedures (U- and UP-experiments) with short applications of ultrasound (5–10min) were used in the first extraction step. In comparison to the classical extraction, higher or similar yields of low-esterified pectic polysaccharide fractions were obtained from the short ultrasound-assisted extraction, where after sonication the extraction process in the first step was stopped (U-experiments). Prolongation of the extraction time after sonication in the first step to 60min (UP-experiments) resulted in more than 2% higher yields of polysaccharides from the first and second steps, the last representing non-esterified pectic polysaccharides. The major portion of polysaccharides was obtained in the first and second steps, representing 80–89% of the total isolated polysaccharides. In the third step, pectic polysaccharides containing considerable amounts of hemicelluloses were isolated. All polysaccharide fractions were contaminated to various extents with protein. The sonication treatment had no effect on the total phenolics content (0.6–2.0%). The overall antioxidant activity in the 2,2-diphenyl-1-picrylhydrazyl (DPPHf fractions from first and second steps of the classical and ultrasound-assisted extractions was very low. In contrast, the pectin/hemicellulose fractions from the third step, particularly of the U-experiment, exhibited considerable “efficient concentrations” (EC50) ranged from 14 to 21 when compared to that of quercetin (EC50 =0.14) used as positive control. EC50 is defined as the concentration of substrate that causes 50% loss of the DPPH activity. The results suggested that the pumpkin polysaccharide fractions represent dietary fibers with a high content of pectin and/or beneficial antioxidant properties, which might be suitable for functional food applications. [Copyright &y& Elsevier]