An R30 fraction from the growth medium of Aeropyrum pernix was analyzed for the protease that can digest the pathological prion protein isoform (PrPSc) from different species (human, bovine, deer and mouse). Our study has identified and characterized pernisine as a thermostable serine metalloprotease that is secreted from A. pernix and that can digest the pathological prion protein PrPSc.
COBISS.SI-ID: 4107640
In this work, quantitative correlations between the antioxidant properties and the total phenolic content (TPC) of different oil cake extracts were studied. The oil cakes from camelina (Camelina sativa), linseed (Linum usitatissimum), rapeseed (Brassica napus), and two varieties of white mustard (Sinapis alba) were analysed as potential sources of antioxidant compounds. Two solvents of different polarity were used to obtain the extracts, resulting in great variation in antioxidant activity. The highest phenolic content was observed for white mustard, followed by camelina, rapeseed and linseed. The methanolic extracts exhibited higher reducing power (max. rapeseed), 2,2-diphenyl-1-picrylhydrazyl scavenging activity (max. rapeseed) and chelating ability (max. linseed), while the extracts obtained by use of less polar solvent (ethanol) were more efficient in emulsion (max. camelina). White mustard extracts inhibited conjugate diene and triene formation in the lipid homogenous system the most. These antioxidant activities of extracts were comparable to the synthetic antioxidant butylated hydroxytoluene. A lack of positive correlations among the different antioxidant activity assays and total phenolic contents was observed.
COBISS.SI-ID: 4048248
Stability of ascorbic acid (AK) in model systems and food products can be also increased by inclusion into liposomes. Encapsulation of AK into various liposomes stabilizes AK up to 300-fold in model systems containing catalytic concentrations of copper ions in comparison to free AK. Incorporation of cholesterol (chol) into membranes resulted in better thermal stability at higher temperatures than pure dipalmitoylphosphatidylcholine (DPPC) liposomes. The rate of AK oxidation in apple juice, relative to that of free AK, was decreased by two orders of magnitude when encapsulated in DPPC liposomes and by more than one order of magnitude in DPPC/chol liposomes.
COBISS.SI-ID: 3939448
In this study, the antioxidant activities of Camelina sativa methanolic extracts were evaluated by different chemical assays: reducing power, 2,2-diphenyl-1-picrylhydrazyl (DPPH•) assay, the β-carotene bleaching method and the metal chelating activity assay. An LC-MS profiling method was used for a comprehensive study of the phenolic compounds and their representation in camelina seeds, cake and oil. For this purpose, 4-vinyl derivatives of hydroxycinnamic acids were synthesized by thermal decarboxylation of the corresponding phenolic acids and sinapine was isolated from kale (Brassica oleracea) applying a new method and confirmed by NMR. The results revealed that besides the total phenolic content and antioxidant activity, seeds and cake also possess a similar phenolic profile. In addition to sinapine and 4-vinyl derivatives, other antioxidants were successfully identified: ellagic acid, protocatechuic acid, p-hydroxybenzoic acid, sinapic acid, salicylic acid, catechin, rutin, quercetin and quercetin glucoside. Since after oil pressing most of the phenolic compounds remain in the seed residues, only a few compounds were identified in oil. Camelina cake was found to have the best reducing power and radical scavenging activity, whereas camelina oil with a relatively low phenolic content exhibited the highest iron-chelating capacity and the best inhibitory action against β-carotene bleaching in an emulsified system.
COBISS.SI-ID: 3944568
We investigated the binding of several polyphenols to bovine serum albumin (BSA) at pH 7.5 and 25 °C: catechins [(−)-epigallocatechin-3-gallate, (−)-epigallocatechin, (−)-epicatechin-3-gallate], flavones (kaempferol, kaempferol-3-glucoside, quercetin, naringenin) and hydroxycinnamic acids (rosmarinic acid, caffeic acid, p-coumaric acid). Fluorescence emission spectrometry and molecular docking were applied to compare experimentally determined binding parameters with molecular modelling. Among these polyphenols, epigallocatechin-3-gallate has the highest binding affinity to BSA among catechines. Structurally simpler hydroxycinnamic acids have a very low binding affinity to BSA.
COBISS.SI-ID: 4113784