Comparative study of the phenolic composition of seeds from grapes cv cardinal and alphonse lavallee during last month of ripening

During the last month of ripening, the phenolic composition of seeds from two widely distributed table grapes, cv Cardinal and Alphonse Lavallee, was determined by HPLC/DAD/ESI/MS. Besides, the concentrations of nutrients in leaf blades of grapevine were measured. Generally, the most abundant phenolic in grape seed was gallic acid, followed by methyl gallate and monomeric flavan-3-ols. In comparison to Alphonse Lavallee, the amounts of phenolics were higher in grape seed of Cardinal, in which gallic acid glucoside was not detected. Among analyzed phenolics, the increase of gallic acid was evidenced in grape seed of Cardinal. The most of phenolics decreased during the last month of grape ripening, and some of them had no significantly different content. Results of bivariate correlations showed that the amounts of some phenolics in grape seed of Cardinal increased with increasing of the content of potassium and phosphorus in leaves

Comparative study of the phenolic composition of seeds from grapes cv cardinal and alphonse lavallee during last month of ripening

During the last month of ripening, the phenolic composition of seeds from two widely distributed table grapes, cv Cardinal and Alphonse Lavallee, was determined by HPLC/DAD/ESI/MS. Besides, the concentrations of nutrients in leaf blades of grapevine were measured. Generally, the most abundant phenolic in grape seed was gallic acid, followed by methyl gallate and monomeric flavan-3-ols. In comparison to Alphonse Lavallee, the amounts of phenolics were higher in grape seed of Cardinal, in which gallic acid glucoside was not detected. Among analyzed phenolics, the increase of gallic acid was evidenced in grape seed of Cardinal. The most of phenolics decreased during the last month of grape ripening, and some of them had no significantly different content. Results of bivariate correlations showed that the amounts of some phenolics in grape seed of Cardinal increased with increasing of the content of potassium and phosphorus in leaves

Thermoplastic polyurethanes based on poly(dimethylsiloxane): structure and thermal behavior

Segmented polyurethanes are an important class of thermoplastic elastomers which have potential use as a biomaterial. Biostability, biocompatibility and some other features of polyurethanes can be improved by the introduction of poly(dimethylsiloxane) in the polymer chain. A series of novel thermoplastic polyurethanes was synthesized by two-step polyaddition reaction in solution from 4,4′-diphenylmethane diisocyanate (MDI), 1,4- butanediol (BD) and poly(propylene oxide)-b-poly(dimethylsiloxane)-bpoly(propylene oxide) (PPO-PDMS). The content of PPO-PDMS (i.e. soft segment) was varied between 40 and 90 wt%. The influence of PPO-PDMS content on the structure and thermal properties of copolymers was investigated by FTIR, 1H and 2D NMR spectroscopy, as well as by DSC analysis

Hemijski sastav ekstrakta semenki bele ribizle

From the seeds of white currant (Ribes rubrum, cv. White Champagne), a new sesquiterpenoid glycoside 1 was isolated, along with two known compounds: dihydrophaseic acid 3'-O-beta-D-glucopyranoside (2), and 3-carboxymethyl-indole-1-N-beta-D-glucopyranoside (3). The structure of the new compound was identified as dihydrophaseic acid 3'-O-beta-gentiobioside, based on extensive NMR and MS spectral studies.Iz semena bele ribizle (Ribes rubrum, cv. bela šampanjska) izolovan je novi seskviterpenski glukozid (1), zajedno sa dva poznata jedinjenja: 3'-O-b-D-glukopiranozidom dihidrofazeinske kiseline (2) i 3-karboksimetilindol-1-N-b-D-glukopiranozidom (3). Na osnovu detaljnih NMR i MS studija, struktura novog jedinjenja je određena kao 3'-O-b-genciobiozid dihidrofazeinske kiseline

Detection of biomarkes of adulterated Allium ursinum with Convallaria majalis and Arum maculatum

A. ursinum and poisonous adulterants C. majalis and A. maculatum were used as a model for detection of adulterants in edible plant. A. Ursinum samples were spiked with C. Majalis and A. Maculatum to mimic adulteration. Metabolomic fingerprinting of all samples was performed using 1H NMR spectroscopy (1D zgpr pulse sequence), and the resulting data sets were subjected to multivariate data analysis. As a result of this analysis, signals of adulterants were extracted from the data, and the structures of biomarkers of adulteration from partially purified samples were elucidated using 2D NMR. Thus, isovitexin and vicenin II, azetidine-2-carboxylic acid, and trigonelline indicated adulteration of A. Ursinum samples with C. majalis. Isovitexin was also recognized to be an indicator of adulteration of A. Ursinum with A. maculatum. In conclusion, the case study of A. Ursinum suggested that plant metabolomics approach could be utilized for identification of low molecular weight biomarkers of adulteration in edible plants

Comparative Analysis of Phenolic Compounds in Seven Hypericum Species and Their Antioxidant Properties

A comparative analysis of the phenolic compounds in the 70% EtOH extracts of Hypericum acutum, H. androsaemum, H. barbatum, H hirsutum, H maculatum, and H richeri has been carried out using high-performance liquid chromatography coupled with photodiode array UV detection and high resolution TOF mass spectrometry. Quercetin, astilbin, I3,II8-biapigenin, orientin, 2"-O-acetylorientin, three phenolcarboxylic acids, and eight flavonols 3-O-glycosides were identified in the extracts on the basis of their on-line UV spectra, accurate mass spectral data, and in comparison of retention times with those from the standards. Fingerprint analysis of the extracts revealed significant differences in the qualitative and quantitative chemical composition of the studied species. Antioxidant assays with various reaction mechanisms were used including ferric reducing antioxidant power (FRAP) assay, DPPH, ABTS, superoxide anion radical scavenging capacity and inhibition of liposome peroxidation induced by Fe2+. The most potent were extracts of H acutum and H maculatum indicating this Hypericum species interesting for further research aimed as a potentially new source of biologically active compounds

Supplementary material for the article: Cvetković, M.; Damjanović, A.; Stanojković, T. P.; Đorđević, I.; Tešević, V.; Milosavljević, S.; Gođevac, D. Integration of Dry-Column Flash Chromatography with NMR and FTIR Metabolomics to Reveal Cytotoxic Metabolites from Amphoricarpos Autariatus. Talanta 2020, 206. https://doi.org/10.1016/j.talanta.2019.120248

Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/3348]Supplementary material for: [https://www.sciencedirect.com/science/article/pii/S0039914019308811?via%3Dihub

Flavonoidi iz nadzemnih delova Onobrychis montana subsp. scardica

Rutin (1, main constituent) and two flavone C-glycosides, vitexin (2) and vitexin 2 ''-O-alpha-rhamnopyranoside (3) were isolated from the aerial parts of Onobrychis montana subsp. scardica. They were identified by (1)H-NMR, (13)C-NMR and UV-Vis spectroscopy (procedure with shift reagents), and high resolution ESI-MS. A relatively high content of 1 (5.27 mg/g of dry plant material), measured by HPLC, indicated O. montana subsp. scardica as a new natural source of this biologically active compound. The isolated flavonoid compounds might be of value as chemotaxonomic markers.Iz nadzemnih delova Onobrychis montana subsp. scardica izolovani su rutin (1, glavni sastojak) i dva flavonoidna S-glikozida, viteksin (2) i njegov 2''-O-α-ramnopiranozid (3). Njihova struktura je određena primenom 1H-NMR, 13C-NMR i UV spektroskopije (procedura sa reagensima UV-pomeranja) i masene spektrometrije visokog razlaganja (HR-ESI-MS). Relativno visok sadržaj rutina (5.27 mg/g suvog materijala) određen pomoću tečne hromatografije (HPLC), ukazuje na O. montana subsp. scardica kao nov prirodni izvor ovog biološki aktivnog jedinjenja. Izolovana jedinjenja mogu biti i od vrednosti kao hemotaksonomski markeri