Suberin of Potato (Solanum tuberosum Var. Nikola): Comparison of the Effect of Cutinase CcCut1 with Chemical Depolymerization

Chemical and enzymatic depolymerizations of suberin isolated from potato peel (Solanum tuberosum var. Nikola) were performed under various conditions. Enzymatic hydrolysis with cutinase CcCut1 and chemical methanolysis with NaOMe of suberin yielded monomeric fragments, which were identified as TMS derivatives with GC-MS and GC-FID. The solid, hydrolysis-resistant residues were analyzed with solid state (13)C CPMAS NMR, FT-IR, and microscopic methods. Methanolysis released more CHCl(13)-soluble, material than the cutinase treatment when determined gravimetrically. Interestingly, cutinase-catalyzed hydrolysis produced higher proportions of aliphatic monomers than hydrolysis with the NaOMe procedure when analyzed by GC in the form of TMS derivatives. Monomers released by the two methods were mainly alpha,omega-dioic acids and omega-hydroxy acids, but the ratios of the detected monomers were different, at 40.0 and 32.7% for methanolysis and 64.6 and 8.2% for cutinase, respectively. Thus, cutinase CcCut1 showed higher activity toward ester bonds of alpha,omega-dioic acids than toward the bonds of omega-hydroxy acids. The most abundant monomeric compounds were octadec-9-ene-1,18-dioic acid and 18-hydroxyoctadec-9-enoic acid, which accounted for ca. 37 and 28% of all monomers, respectively. The results of the analyses of the chemical and enzymatic hydrolysis products were supported by the spectroscopic analyses with FT-IR and CPMAS (13)C NMR together with the analysis of the microstructures of the hydrolysis residues by light and confocal microscopy

Solid state (13)C CP-MAS NMR and FT-IR spectroscopic analysis of cuticular fractions of berries and suberized membranes of potato

Cuticular fractions of the important northern berries sea buckthorn (Hippophae rhamnoides) and black currant (Ribes nigrum), and the suberized membrane of red peel potato (Solanum tuberosum var. Asterix), were investigated for the first time with solid state spectroscopic methods. In addition, the ester-bonded aliphatic monomers were analyzed as TMS derivatives by GC-MS after depolymerization with NaOMe catalyzed methanolysis. The fractions inspected by solid state (13)C CP-MAS NMR and FT-IR spectroscopy included isolated cuticular and suberin-enriched membranes, i.e. raw cutin and suberin, the non-depolymerizable fractions and further cellulase- and pectinase-resistant fractions. Spectroscopic results supported the findings of the monomeric composition of ester-bound cutin, confirmed the presence of polysaccharides and an aromatic, possibly lignin-like, fraction and also suggested the presence of a nondegradable cutan-type polymer in the berry cuticular fraction. Black currant peel cutin and receptacle cutin were found to differ from each other in composition, notably in terms of the abundance of monomeric, aromatic and polysaccharide fractions. Some effect of latitudinal growth on the composition of cuticular fractions was observed for black currants grown in northern and southern Finland. The spectra of potato suberin were similar to the spectra of black currant receptacles, but the berry had even higher proportio'ns of aromatic components. (C) 2010 Elsevier Inc. All rights reserved.ABS Graduate SchoolTEKESLIPFUN projectCOST Action 928 projectTurku University FoundationAssociation of Finnish Chemical Societie

Postprandial response on fatty meal is affected by sea buckthorn (Hippophae rhamnoides) supplementation: NMR metabolomics study

Nuclear magnetic resonance fingerprinting (H-1 NMR) combined with different statistical tools was used to assess the effect of phenolics-rich sea buckthorn berries on postprandial plasma and urine after consumption of a fatty meal and to obtain information about the absorption and excretion of ethyl-O-beta-D-glucopyranoside and various inositols in sea buckthorn berries. Analyses of plasma samples indicated the delayed postprandial increase of lipid levels and the restrained increase of 3-hydroxy butanoic acid and N-acetyl glycoproteins when sea buckthorn meal was compared to control. The rise of acetic acid concentration and the occurrence of methyl-O-beta-D-glucopyranoside and ethyl-O-beta-D-glucopyranoside, but no inositols, were noticed after sea buckthorn meal in plasma. The methylglucoside was detected for the first time in plasma in relation to sea buckthorn containing diet, and the compound has subsequently been identified for the first time in sea buckthorn. Analyses of postprandial urine samples revealed a lower creatinine and dimethylamine concentrations and a higher hippuric acid concentration in urine after the berry meal when compared to the control. Excretion of the ethylglucoside in urine was detected after the sea buckthorn meal which indicates that this alkyl sugar is not efficiently metabolized by human body. (C) 2013 Elsevier Ltd. All rights reserved

H-1 NMR-based metabolic fingerprinting of urine metabolites after consumption of lingonberries (Vaccinium vitis-idaea) with a high-fat meal

The use of NMR metabolomics in clinical trials is growing; however, reports of postprandial experiments in humans are scarce. The present study investigated whether consumption of lingonberries as a supplement to an oil-rich meal modifies the postprandial fingerprints of human urine. Urine samples were analysed by H-1 NMR, and untargeted multivariate analysis was applied to the data for comprehensive fingerprinting. A clear separation of postprandial lingonberry meal samples was revealed. To evaluate statistical differences, a targeted approach was applied for the informative spectral areas. Significantly (p < 0.05) increased levels of polyphenol metabolites, hippuric acid and 4-hydroxyhippuric acid, and decreased creatinine and dimethylamine levels were the major explanations for the grouping of the postprandial samples after the different meals. Thus, inclusion of polyphenol-rich lingonberry powder in a rapeseed oil-rich meal modifies the metabolic profile of urine which may be used to reveal both consumption of berries and health-promoting changes in the common metabolism. (C) 2012 Elsevier Ltd. All rights reserved