Search results for "liquid [scintillation counter]"
showing 10 items of 1764 documents
Anti-Bacterial Activity and Online HPLC-DPPH Based Antiradical Kinetics of Medicinal Plant Extracts of High Relevance for Cosmetics Production
2018
The present study provides an assessment of extracts of six medicinal plants for their applicability in cosmetic formulations aimed at anti-UV protection and anti-acne treatment. Ethanol extracts of Chelidonium majus L., Myrtus communis L., Hamamelis virginiana L., Juniperus communis L., Alchemilla vulgaris and Ilex paraguariensis are analysed for the phytochemical content, antimicrobial activity, antiradical activity and antiradical kinetics. The phytochemical composition of the plants is investigated by LC-MS analysis and the most active antioxidants in plant extracts are determined by online HPLC-DPPH assay. The kinetic parameters of the antiradical reaction are determined both for the s…
Chromatographic separation and partial identification of glycosidically bound volatile components of fruit
1990
Abstract Synthetic monoterpenic and aromatic β- d -glucosides and β- d -rutinosides were separated by Fractogel TSK HW-40 S chromatography according to their molecular size and interactions occurring between the aglycone moiety and the gel matrix. Under these conditions terpenyl rutinosides were eluted before the homologous glucoside derivatives. In the two classes, monoglucosides and rutinosides, aromatic glycosidically bound components had lower retention times than the corresponding terpenyl components. The use of over-pressure layer chromatography (OPLC) allowed the separation of glucoside and rutinoside derivatives, and in these two classes aromatic and several monoterpene compounds we…
Identification of Casein Phosphopeptides in β-casein and Commercial Hydrolysed Casein by Mass Spectrometry
2006
Casein phosphopeptides (CPPs) in commercial hydrolysed casein (CE90CPP) and in β-CN (β-CN) after simulated gastrointestinal digestion (gastric stage pepsin, pH =2, 37°C 2h) and intestinal stage (pancreatic-bile extract, pH =5.2, 37°C 2h) were sequenced by on-line reversed-phase high performance liquid chromatography coupled to electrospray ionisation tandem mass spectrometry (RP-HPLC-ESIMS/MS). In β-CN digest five peptides that contained four to five phosphate groups and the cluster sequence SpSpSpEE (residues 17-21) were identified. All CPPs with one exception β-CN(1-24)4P, had the protein fragment β-CN(1-25)4P, which is one of the main CPPs produced in vivo digestion of casein and the re…
Wild
2021
Graphical abstract
Effect of Sunlight Exposure on Anthocyanin and Non-Anthocyanin Phenolic Levels in Pomegranate Juices by High Resolution Mass Spectrometry Approach
2020
Quali-quantitative analyses of anthocyanins and non-anthocyanin phenolic compounds performed with the use of liquid chromatography coupled with high resolution mass spectrometry, were evaluated in juice of pomegranate fruits (&lsquo
Effect of Seasonal Storage on Single-Stem Bark Extractives of Norway Spruce (Picea abies)
2021
Increasing the net value of forestry side-streams has both ecological as well as economic benefits for emerging biorefining industries. Spruce bark represents one of the nature’s abundant sources of valuable extractives. In this study, the impact of storage on the quality and quantity of Norway spruce (Picea abies) extractives was examined as a function of storage time, environmental conditions and season (i.e., winter or summer). The bark from stored spruce saw logs was extracted with an accelerated solvent extractor (ASE) at 120 °C with hexane and water. The produced extracts were analysed qualitatively and quantitatively by gas chromatography with a flame ionisation detector (GC-FID) and…
Liquid Crystal Phases in Suspensions of Charged Plate-Like Particles
2012
International audience; Anisotropic interactions in colloidal suspensions have recently emerged as a route for the design of new soft materials. Nonisotropic particles can form nematic, smectic, hexatic, and columnar liquid crystals. Although the formation of these phases is well rationalized when excluded volume is solely at play, the role of electrostatic interactions still remains unclear and even less so when particles present a charge heterogeneity, for example, clays. Here, we use Monte Carlo simulations of concentrated suspensions of charged disk-like particles to reveal the role of Coulomb interactions and charge anisotropy underlying liquid crystal formation and structures. We obse…
Simultaneous Determination of Caffeine and Chlorogenic Acids in Green Coffee by UV/Vis Spectroscopy
2017
A simple method for the simultaneous determination of caffeine and chlorogenic acids content in green coffee was reported. The method was based on the use of UV/Vis absorption. It is relevant that the quantification of both caffeine and chlorogenic acids was performed without their preliminary chemical separation despite their spectral overlap in the range 250–350 nm. Green coffee was extracted with 70% ethanol aqueous solution; then the solution was analyzed by spectroscopy. Quantitative determination was obtained analytically through deconvolution of the absorption spectrum and by applying the Lambert-Beer law. The bands used for the deconvolution were the absorption bands of both caffein…
The Bioactive Compounds and Antioxidant Activity of Food Products of Rhizophora stylosa Fruit (Coffee and Tea Mangrove)
2018
The objective of this study is to investigate the bioactive compounds and antioxidant activity of coffee and tea mangrove (locally known in Indonesia) produced from the fruit of Rhizophora stylosa. Furthermore, three raw materials of coffee mangrove were also investigated to clarify their potencies. The crude extracts of five samples were subjected to antioxidant assay using DPPH. The results show that the extract of tea mangrove has the strongest activity; then, it was successfully fractionated using different polarity of solvents and yielded acetone and methanol fractions that had high antioxidant activity. The acetone fraction was purified and gave fractions A1, A2, A3, A4, A5, and A6, b…
Guava: phytochemical composition of a potential source of antioxidants for cosmetic and/or dermatological applications
2017
Made available in DSpace on 2018-11-28T14:21:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-01-01. Added 1 bitstream(s) on 2019-10-09T18:26:25Z : No. of bitstreams: 1 S1984-82502017000200612.pdf: 803011 bytes, checksum: 199524e8d40cccb25490594ec61b3ed8 (MD5) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) PADC-FCF-UNESP Fundação para o Desenvolvimento da UNESP (FUNDUNESP) Guava (Psidium guajava L.) is a native fruit of the American tropics with commercial applications for its taste, flavor and aroma. Numerous pharmacological uses have been described for it, such as the antiseptic effect of it…