2‐Hexadecenal inhibits growth of C6 glioma cells

2‐Hexadecenal (2HD) formation in the organism occurs via irreversible enzymatic degradation of sphingosine‐1‐phosphate or nonenzymatic γ‐, UV‐, or HOCl‐induced destruction of a number of sphingolipids including S1P. The current research focuses on the study of 2HD effects on C6 glioma cells growth. The results obtained show that 2HD causes a dose‐dependent decrease in proliferative and mitotic indices. The change in the mitotic index is due to the redistribution of cells in the different phases of mitosis. These processes are accompanied by cytoskeleton rearrangement and changes in cell morphology, which are expressed in F‐actin redistribution, change in the number and type of filopodia and fibrils, leading to cell shape changes, decrease in intercellular contacts and monolayer rarefaction. Cells treatment with 2HD leads to apoptosis induction and signalling pathways modification, including activation of JNK, p38, and ERK1/2 MAPK but not PI3K. The effects observed are not related to the cytotoxicity of 2HD. Significance of the study: 2HD—an unsaturated aldehyde, which level can rise under conditions of oxidative stress as a result of nonenzymatic sphingolipids' destruction. The mechanisms of 2HD action on various cell types have not been sufficiently studied. Therefore, the study on functional role of this aldehyde in different cell types that may be its target is relevant. This study demonstrated that 2HD inhibits growth of C6 glioma cells due to modification of intracellular processes of signal transduction, cytoskeleton rearrangement, change in the mitotic regimen and apoptosis induction.     

Radical-regulating and antiviral properties of ascorbic acid and its derivatives

The ability of ascorbic acid and a number of its derivatives to suppress replication of Herpes simplex virus type I was investigated in human rhabdomyosarcoma cell line. In parallel, interaction of the test compounds with carbon- and oxygen-centered radicals formed on radiolysis of hydroxyl-containing organic compounds was studied using the steady state radiolysis method. It has been shown that 2-O-glycoside of ascorbic acid, displaying marked antiviral properties against Herpes simplex virus type I, is also capable of inhibiting fragmentation and recombination reactions of α-hydroxyl-containing carbon-centered radicals while not affecting processes involving oxygen-centered radicals.     

Effects of alpha-tocopherol and related compounds on reactions involving various organic radicals

Effects of alpha-tocopherol, PMC, and a number of the respective sulfur-containing analogues on reactions involving various organic radicals were studied. The test compounds were found to interact with alkyl radicals more effectively than with peroxyl radicals. The presence of a sulfur atom in structures of the respective analogues did not produce significant effects on reactivity. Derivatives of 5-hydroxy-1,3-benzoxathiol-2-one and 6-hydroxy-1,4-benzoxathiin-2(3H)-one displayed a high reactivity toward alpha-hydroxyalkyl radicals.     

Effects of vitamins, coenzymes and amino acids on reactions of homolytic cleavage of the O-glycoside bond in carbohydrates

It has been established that vitamins B1, K3 and C, coenzyme Q0 and amino acids cysteine and histidine effectively inhibit reactions of homolytic cleavage of the O-glycoside bond, which are responsible for the destruction of di- and polysaccharides on gamma-irradiation or the action of other reactive radical initiators. This effect was shown to originate from either oxidation or reduction of the radicals of carbohydrates undergoing destruction.     

Evolutionary history of tall fescue morphotypes inferred from molecular phylogenetics of the <Emphasis Type="Italic">Lolium</Emphasis>-<Emphasis Type="Italic">Festuca</Emphasis>species complex

Background  

The agriculturally important pasture grass tall fescue (Festuca arundinacea Schreb. syn. Lolium arundinaceum (Schreb.) Darbysh.) is an outbreeding allohexaploid, that may be more accurately described as a species complex consisting of three major (Continental, Mediterranean and rhizomatous) morphotypes. Observation of hybrid infertility in some crossing combinations between morphotypes suggests the possibility of independent origins from different diploid progenitors. This study aims to clarify the evolutionary relationships between each tall fescue morphotype through phylogenetic analysis using two low-copy nuclear genes (encoding plastid acetyl-CoA carboxylase [Acc1] and centroradialis [CEN]), the nuclear ribosomal DNA internal transcribed spacer (rDNA ITS) and the chloroplast DNA (cpDNA) genome-located matK gene. Other taxa within the closely related Lolium-Festuca species complex were also included in the study, to increase understanding of evolutionary processes in a taxonomic group characterised by multiple inter-specific hybridisation events.     

Comparison of homoeolocus organisation in paired BAC clones from white clover (<Emphasis Type="Italic">Trifolium repens</Emphasis> L.) and microcolinearity with model legume species

Background  

White clover (Trifolium repens L.) is an outbreeding allotetraploid species and an important forage legume in temperate grassland agriculture. Comparison of sub-genome architecture and study of nucleotide sequence diversity within allopolyploids provides insight into evolutionary divergence mechanisms, and is also necessary for the development of whole-genome sequencing strategies. This study aimed to evaluate the degree of divergence between the O and P' sub-genomes of white clover through sequencing of BAC clones containing paired homoeoloci. The microsyntenic relationships between the genomes of white clover and the model legumes Lotus japonicus and Medicago truncatula as well as Arabidopsis thaliana were also characterised.     

Formation of phosphatidic acid, ceramide, and diglyceride on radiolysis of lipids: identification by MALDI-TOF mass spectrometry

By use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, phosphatidic acid was found to be the main product of γ radiolysis of cardiolipin, phosphatidylinositol, and phosphatidylglycerol. It has been shown that γ irradiation of such glycolipids as cerebroside and galactosyl diglyceride leads to formation of ceramide and diglyceride, respectively. These findings, combined with those obtained earlier, allowed an assumption to be made that, owing to radiation-induced free radical fragmentation of lipids in their polar moiety, formation of signaling molecules can occur.     

Novel (3,5-di-tert-butyl-2-hydroxy-phenylcarbamoyl)-alkanoic acids as potent antioxidants

A series of novel phenolic antioxidants of amphiphilic structure has been synthesized. Investigations into the influence of aliphatic spacer length and nature of a hydrophilic anchor on the antioxidant activity allowed elucidating certain structure requirements for the membrane-addressed antioxidant designing.     

Effects of B group vitamins on reactions of various alpha-hydroxyl-containing organic radicals

Effects of vitamins B1, B2, B6, and pyridoxal phosphate (PPh) on final product formation in radiolysis of aqueous solutions of ethanol, ethylene glycol, alpha-methylglycoside, and maltose were studied. It has been found that vitamin B2 and PPh effectively oxidize R*CHOH species, while suppressing their recombination and fragmentation reactions, thereby increasing the yields of the respective oxidation products. Vitamins B1 and B2 are capable of reducing alcohol radicals to the respective initial molecules, decreasing the yields of the radical transformation products.     

Human thyroid peroxidase: Inhibition of the iodide ion and 3,3′,5,5′-tetramethylbenzidine oxidation by phenolic antioxidants

A comparative kinetic study on the poly(gallic acid disulfide) (poly(DSGA)) inhibition of the iodide ion oxidation and on the 2-hydroxy-3,5-di-tert-butyl-N-phenylaniline (butaminophene) inhibition of 3,3′,5,5′-tetramethylbenzidine (TMB) oxidation involving human thyroid peroxidase (hTPO) and horseradish peroxidase (HRP) was performed. The inhibition processes were characterized with the inhibition constantsK _i and stoichiometric inhibition coefficientsf, indicating the number of radical particles perishing on one inhibitor molecule. In the case of poly(DSGA), theK _i values for the I⁻ oxidation were 0.60 and 0.04 μM, and the coefficientsf were 13.6 and 16.5 for hTPO and HRP, respectively, which evidences the regeneration and high effectiveness of the polymeric inhibitor. In the case of butaminophene, theK _i values for TMB oxidation were 38 and 46 μM for hTPO and HRP, respectively. The coefficientsf were 1.33 and 1.47, respectively, to reveal that butaminophene does not regenerate. The inhibition mechanisms for I⁻ and TMB oxidation involving the two peroxidases are discussed.