Spectroscopy studies of interaction hypericin with an anti-cancer therapy drug doxorubicin.

The presented study was designed to estimate the ability of hypericin to interact with the anticancer drug doxorubicin. The hetero-association of hypericin and doxorubicin was investigated with absorption and fluorescence spectroscopy methods in aqueous solution of DMSO in two-component mixtures: doxorubicin-hypericin and three component mixtures: DNA-doxorubicin-hypericin. The data indicate that hypericin forms complexes with doxorubicin and that the association constants are on the order of 300,000 M in a buffer with 30% DMSO content.

Water dynamics in eggs by means of Nuclear Magnetic Resonance relaxometry.

H Nuclear Magnetic Resonance relaxometry has been applied to reveal dynamical properties of water molecules embedded into egg yolk and white of three species: turkey, chicken and quail. Two fractions of water molecules, referred to as confined-water and free-water fractions, have been revealed. It has been demonstrated that translation diffusion of the confined-water fraction is three-dimensional.

Cadmium ion-chlorophyll interaction - Examination of spectral properties and structure of the cadmium-chlorophyll complex and their relevance to photosynthesis inhibition.

Chlorophyll was shown to spontaneously form a complex with cadmium, which is incorporated at the central position of the chlorophyll molecule porphyrin ring, where it replaces magnesium. The rate of complex formation depended on the ratio of Cd2+ ions to chlorophyll concentration in the solution. In solutions with chlorophyll concentration of C = 1 × 10 M and Cd concentrations of C = 1 × 10 M, C = 1 × 10 M and C = 9 × 10 M, Cd-Chl complex formation was completed after 200 h, 50 h and 33 h, respectively.

Evaluation of the characteristics of some plant polyphenols as molecules intercepting mitoxantrone.

This paper contains the results of a study on the interactions between mitoxantrone and some bioactive polyphenols. It has been demonstrated that polyphenols can intercept mitoxantrone. Quercetin shows the highest affinity for complexing with mitoxantrone, in contrast to resveratrol, which shows the lowest affinity.

Acetylpyrene-labelled 7-methylguanine nucleotides: unusual fluorescence properties and application to decapping scavenger activity monitoring.

7-Methylguanosine (m(7)G) nucleotides labelled with acetylpyrene (AcPy) were synthesized as fluorescent mRNA 5' end (cap) analogues. The unique fluorescent properties of m(7)G-AcPy conjugates, different from G-AcPy, can be applied to studying various mRNA cap-related processes including the evaluation of putative inhibitors of DcpS enzyme-a therapeutic target in neuromuscular diseases.

Uptake and phytotoxicity of anthracene and benzo[k]fluoranthene applied to the leaves of celery plants (Apium graveolens var. secalinum L.).

The above-ground parts of celery plants were exposed to two polycyclic aromatic hydrocarbons (PAHs): 3-ring anthracene (ANT) and 5-ring benzo[k]fluoranthene (BkF), and the combination of ANT and BkF. After 43 days of exposure (overall dose of 1325µg/plant), celery plants retained only 1.4% of the total dose of ANT and 17.

Synthesis and evaluation of fluorescent cap analogues for mRNA labelling.

We describe the synthesis and properties of five dinucleotide fluorescent cap analogues labelled at the ribose of the 7-methylguanosine moiety with either anthraniloyl (Ant) or N-methylanthraniloyl (Mant), which have been designed for the preparation of fluorescent mRNAs transcription . Two of the analogues bear a methylene modification in the triphosphate bridge, providing resistance against either the Dcp2 or DcpS decapping enzymes. All these compounds were prepared by ZnCl-mediated coupling of a nucleotide P-imidazolide with a fluorescently labelled mononucleotide.

Nano, micro, and bulk structures in atactic polystyrene-syndiotactic polystyrene blends obtained in situ in presence of the CpTiCl3/SiO2/MAO catalysts (Cp-cyclopentadienyl, MAO-methylaluminoxane).

CpTiCl3/SiO2/MAO (Cp=cyclopentadienyl, MAO - methylaluminoxane) catalysts, where the Al:Ti varies from 20:1 to 500:1, were used in styrene polymerization. Atactic - syndiotactic polystyrene blends (aPS-sPS) were obtained in situ, the morphology of which was investigated by means of scanning electron microscopy. The blends morphology changed according to the kind of catalytic centers: cationic and syndiotactic on the catalyst surface, which create individually atactic or syndiotactic polystyrenes forming specific blends containing nano or micro-forms: when the Al:Ti ranges from 50:1 and to 100:1 in the blends, there occur nano-sPS particles 40-120 nm in size, if the Al:Ti≥300:1, the filament of δ-sPS polymorph, is produced where the filament size ranged from 30 to 10 nm.

The hydrolysis of 5'-CAP dinucleotide analogs: catalysis by bi- and terpyridine complexes of Cu²⁺ and Zn²⁺ ions.

The kinetics of the hydrolysis of P(1)-(7-methylguanosinyl-5') P(3)-(guanosinyl-5') triphosphate (m(7)GpppG), P(1)-(7-methylguanosinyl-5') P(4)-(guanosinyl-5') tetraphosphate (m(7)GppppG), and diadenosine 5', 5'( ')-P(1),P(3) -triphosphate (ApppA) in the presence of several Cu(2+) or Zn(2+) ions complexed with bi- or terpyridine has been studied at pH 8.0 and 60 °C. Time-dependent product distributions at various metal complex concentrations have been determined by capillary zone electrophoresis and reversed-phase high performance liquid chromatography.

Hydrolysis of 5',5'-tri- or tetraphosphate-mRNA 5'-cap analogs promoted by Cu2+ or Zn2+ metal ions.

Kinetics of the hydrolysis of a P(1)-(7-methylguanosinyl-5') P(3)-(guanosinyl-5') triphosphate (m(7)GpppG), P(1)-(7-methylguanosinyl-5') P(4)- (guanosinyl-5') tetraphosphate (m(7)GppppG), diadenosine-5',5'''-P(1),P(3)-triphosphate (ApppA), and diadenosine-5',5'''-P(1),P(4)-tetraphosphate (AppppA) promoted by Cu(2+) or Zn(2+) has been investigated. Time-dependent products distributions at various metal ion concentrations have been determined by CZE and HPLC-RP. The results show that in acidic conditions, in the presence of metal ion, the predominant hydrolytic reaction is the cleavage of 5',5'-oligophosphate bridge.

Determination of lead, cadmium, and persistent organic pollutants in wild and orchard-farm-grown fruit in northeastern Poland.

The concentrations of the heavy metals lead (Pb) and cadmium (Cd) were determined in berries (blackberry, raspberry, bilberry, wild strawberry), and hazelnuts picked from plants in the wild as well as in fruit (blackberry, raspberry, blueberry) and hazelnuts picked from orchard-farmed plants in northeastern Poland. The levels of seven congeners of polychlorinated biphenyls (PCB(7)), gamma isomer of hexachlorocyclohexane (gamma-HCH), and sum of dichlorodiphenyl trichloroethane and its metabolites (SigmaDDT) were also measured in plants and nuts. In addition, the concentrations of Pb, Cd, PCB(7,) gamma-HCH, and SigmaDDT were determined in the surface samples of soil from the sites of fruit picking.

Natural compounds in the human diet and their ability to bind mutagens prevents DNA-mutagen intercalation.

Human diet may contain many mutagenic or carcinogenic aromatic compounds as well as some beneficial physiologically active dietary components, especially plant food phytochemicals, which act as mutagenesis or carcinogenesis inhibitors. This study compared the binding properties of natural compounds in the human diet (caffeine, theophylline, theobromine, and resveratrol) with a water-soluble derivative of chlorophyll to bind to acridine orange, a known mutagen. An analysis was conducted to determine which substances were effective binding agents and may thus be useful in prevention of chemical-induced mutagenesis and carcinogenesis.

Attenuation of acridine mutagen ICR-191--DNA interactions and DNA damage by the mutagen interceptor chlorophyllin.

We have investigated the ability of chlorophyllin (CHL) to interact with acridine mutagen ICR-191 (2-methoxy-6-chloro-9-(3-(2-chloroethyl)aminopropylamino)acridine) and also its ability to decrease binding of ICR-191 to DNA in a simple three-component competition system: CHL-ICR-DNA. Our data indicate a strong association of ICR-191 with CHL, stronger even than the association of ICR-191 with DNA. Calculations based on the measured affinity data show that a two- to three-fold excess of CHL reduces by about two-fold the concentration of the mutagen-DNA complex.

Homo-polymerization of alpha-olefins and co-polymerization of higher alpha-olefins with ethylene in the presence of CpTiCl2(OC6H4X-p)/MAO catalysts (X = CH3, Cl).

Cyclopentadienyl-titanium complexes containing -OC6H4X ligands (X = Cl,CH3) activated with methylaluminoxane (MAO) were used in the homo-polymerization of ethylene, propylene, 1-butene, 1-pentene, 1-butene, and 1-hexene, and also in co-polymerization of ethylene with the alpha-olefins mentioned. The -X substituents exhibit different electron donor-acceptor properties, which is described by Hammett's factor (sigma). The chlorine atom is electron acceptor, while the methyl group is electron donor.

The "interceptor" properties of chlorophyllin measured within the three-component system: intercalator-DNA-chlorophyllin.

In aqueous solutions, in the presence of double-stranded DNA, chlorophyllin (CHL) forms complexes with each of the three DNA intercalators: acridine orange (AO), quinacrine mustard (QM), and doxorubicin (DOX). The evidence for these interactions was obtained by measurement changes in the absorption and fluorescence spectra of the mixtures containing DNA and intercalators during titration with CHL. A model of simple competition between DNA and CHL for the intercalator was used to define the measured interactions.

Phytotoxicity and accumulation of anthracene applied to the foliage and sandy substrate in lettuce and radish plants.

The effects of anthracene (ANT) on the growth of two species of vegetable plants (Lactuca sativa L. and Raphanus sativus L.), which play an important role in the human diet, were studied.

The mimetics of antiadhesive peptides as the inhibitors of Mycobacterium kansasii phagocytosis.

The alpha-guanidino acids derived of 15 proteinaceous amino acids, omega-guanidino acids with gradually increased hydrocarbon chains, and amidinated dipeptides, were tested as the mimetics of antiadhesive peptides in Mycobacteria phagocytosis inhibition. The crystal structure of omega-guanidino acids used was determined by X-ray structural analysis. It follows from our experiments that the proper distance between guanidine and carboxyl groups of effector molecules is of decisive importance for their inhibitory activity.

Immunosuppressory activity of ubiquitin fragments containing retro-RGD sequence.

A peptide fragment corresponding to the ubiquitin(50-59) sequence (LEDGRTLSDY) (U50-59) possesses a very high immunosuppressory activity, comparable to that of cyclosporine, both in the cellular and humoral immune responses. We found that the pentapeptide DGRTL (U52-56) is the shortest, effective immunosuppressory fragment of ubiquitin, although its potency is weaker than that of U50-59. Replacement of each consecutive residue with alanine in U52-56 allowed identification of essential amino acids involved in the immunosuppression.

On the peptide-antipeptide interactions in interleukin-1 receptor system.

Interleukin-1 receptor antagonist (IL-1Ra) and vaccinia virus protein C10L share a VTXFYF motif, with X being Lys or Arg residue, respectively. Peptides of such sequence compete successfully with IL-1 for the cellular receptor. A pair of complementary peptides, based on the Siemion's hypothesis on the periodicity of the genetic code (QWLNIN and QWANIN), and another pair, in which, following the Root- Bernstein theory, Lys was used as complementary amino acid to Phe (QWLKIK and QWAKIK), were investigated for the peptide-antipeptide interactions using mass spectrometry (ESI-MS) and circular dichroism (CD) methods.

Synthesis, conformation, and immunosuppressive activity of CLX and its analogues.

The CLX peptide isolated from flax seed has a sequence cyclo-(PPFFILLX), where X is a nonproteinaceous amino acid residue, (2S,4R) 4-amine-N-methylproline. Picur, B.; Lisowski, M.

Analogs of RGDVY and GRGD peptides inhibit Mycobacterium kansasii phagocytosis.

Continuing our research on Mycobacteria kansasii phagocytosis inhibition, we have examined in that context three series of peptides derived from the RGDVY and GRGD sequences. It was found that the levels of the inhibitory activity depend on the amino acid composition as well as on the particular peptide sequence. Distinct inhibitory activity was found in the case of thymopentin (RKDVY), the active fragment of thymopoietin.

Antiadhesive peptides as the inhibitors of Mycobacterium kansasii phagocytosis.

Initial entry of Mycobacteria into the cells depends upon the formation of a molecular complex between Antigen 85 (Ag85), located on the bacterial cell wall, and serum protein-fibronectin (FN) [Nat. Struct. Biol.

Interactions of chlorophyllin with acridine orange, quinacrine mustard and doxorubicin analyzed by light absorption and fluorescence spectroscopy.

The present study was designed to estimate the ability of chlorophyllin (CHL) to interact with two acridine mutagens, quinacrine mustard (QM) and acridine orange (AO), and with the antitumor anthracycline doxorubicin (Dox). To this end, aqueous solutions of QM, AO or Dox during titration with CHL were subjected to spectrophotometry and spectrofluorimetry to detect possible interactions between these reagents. The data indicate that CHL forms complexes with AO, QM or Dox in these solutions.

[The occurrence of polycyclic aromatic hydrocarbons (PAHs) in infusion of natural coffee, coffee substitute and cocoa].

The content of polycyclic aromatic hydrocarbons (PAHs) in chosen condiments commercially available was investigated. The concentration of these compounds in infusion of natural coffee, coffee ersatz and cocoa was determined by gas chromatography. Fluoranthene, pyrene and benz(a)anthracene were the PAHs, which the most frequently were present in infusions of unfiltered natural coffee.