title: Structural diversity of pectins isolated from the Styrian oil-pumpkin (Cucurbita pepo var. styriaca) fruit.
abstract: 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.
authors: Institute of Chemistry, Center for Glycomics, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 38 Bratislava, Slovak Republic. chemzuko@savba.sk
authors: Zuzana
authors: Z
authors: Košťálová
authors: Zdenka
authors: Z
authors: Hromádková
authors: Anna
authors: A
authors: Ebringerová
mesh_terms: D000107:Acetylation; D000143:Acids / Q000737:chemistry; D001089:Arabinose / Q000737:chemistry; D005591:Chemical Fractionation / Q000379:methods; D028464:Cucurbita / Q000737:chemistry*; D004492:Edetic Acid / Q000737:chemistry; D005638:Fruit / Q000737:chemistry*; D005690:Galactose / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006851:Hydrochloric Acid / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010368:Pectins / Q000737:chemistry / Q000302:isolation & purification*; D012972:Sodium Hydroxide / Q000737:chemistry; D012995:Solubility; D014867:Water / Q000737:chemistry
chemical_list: D000143:Acids; D006603:Hexuronic Acids; D014867:Water; C007819:galacturonic acid; D012972:Sodium Hydroxide; D010368:Pectins; D004492:Edetic Acid; D001089:Arabinose; D006851:Hydrochloric Acid; D005690:Galactose