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The (4-amino-2,6-dichlorophenyl)-bis(2,4,6-trichlorophenyl)methyl amino radical was prepared from a solution of ammonia gas and tris(2,4,6-trichlorophenyl)carbenium hexachloroantimoniate in CH2Cl2. Electron spin resonance revealed a small spin-orbit coupling. Electrochemical measurements indicated the compound undergoes condensation reactions without impairing its radical character.

A study was conducted on the chlorocarbon perchloro-2-methylnaphthalene. The chlorocarbon was prepared through the treatment of 2H-heptachloronaphthalene with CCl3F in the presence of AlCl3, yielding heptachloro-7-(trifluoromethyl)-naphthalene, which in CS2 and with an excess of AlCl3 yields the target chlorocarbon. Elemental analysis, 13C nuclear magnetic resonance and infrared spectra were used to characterize the chlorocarbon, while the electronic spectrum and x-ray analysis were used to observe its molecular structure.

3,4,5-trichloro-2-6-bis(bis(pentachlorophenyl)methyl)pyridine reacts with the basic reagent BCR to produce a red solution that yields the perchloro-2,6-bis-(diphenylmethyl)pyridine-alpha,alpha'-ylene biradical and monoradical impurities on oxidation. A ferromagnetic coupling unit, the trichloro-m-pyridylene spacer, connects two trivalent carbon atoms of the biradical. Magnetic susceptibility measurements show the triplet nature of the ground state of the biradical. Cyclic voltammogram reveals reversible and irreversible peaks due to the formation of anion and dianion, respectively.

The chlorination of 1- and 2-methylnaphthalenes with Silberrad's reagent (SO2Cl, S2Cl2 and AlCl3) providesa host of polychlorinated naphthalenes and indanes. Of these, 7- and 8-(chloromethyl)heptachloronaphthalenes are used to alkylate pentachlorobenzenevia an AlCl3-catalyzed Friedel-Crafts reaction. The product, 2-(pentachlorobenzyl)heptachloronaphthalene, yields diphenyl methane and 1H-heptachloronaphthalene when heated with pentachlorobenzene and AlCl3. The original target, 2H-heptachloronaphthalene, is obtained instead via a differentroute using 7-(chloromethyl)heptachloronaphthalene.

The condensation reactions between (4-amino-2,6-dichlorophenyl)bis(2,4,6-tricholorophenyl) methyl radical and acetylacetone or 1,4-bis(5-methyl-2-thienyl)1,4-butanedione yield [2,6-dichloro-4-[2,5-bis(5-methyl-2-thienyl)-1-pyrrolyl]phenyl]bis(2,4,6-trichlorophenyl)methyl radical is investigated. An example of violation of the topology rule concerning disjoint rho-phenylene-bridged homospin diradicals in which the triplet is the ground state is reported.

The present study was undertaken to examine the physicochemical properties of three overlapping peptides belonging to the E2 envelope protein of Hepatitis G virus (GBV-C/HGV) and its interaction with phospholipid biomembrane models using biophysical techniques. We describe our findings concerning the surface activity and the interaction of the peptides with monolayers and liposomes composed of the zwitterionic phospholipids dipalmitoylphosphatidylcholine and dimyristoylphosphatidylcholine (DMPC) and a mixture of DMPC with the anionic phospholipid dimyristoylphosphatidylglycerol. The results inform about the effect of the chain length on their interaction with biomembrane models. The longest chain peptide interacts in a higher extent with all the phospholipid studied as a result of a combination of hydrophobic and electrostatic forces.

The present work examines the relationship between the antimicrobial activity of novel arginine-based cationic surfactants and the physicochemical process involved in the perturbation of the cell membrane. To this end, the interaction of these surfactants with two biomembrane models, namely, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) multilamellar lipid vesicles (MLVs) and monolayers of DPPC, 1,2-dipalmitoyl-sn-glycero-3-[phospho-rac-(1-glycerol)] sodium salt (DPPG), and Escherichia coli total lipid extract, was investigated. For the sake of comparison, this study included two commercial antimicrobial agents, hexadecyltrimethylammonium bromide and chlorhexidine dihydrochloride. Changes in the thermotropic phase transition parameters of DPPC MLVs in the presence of the compounds were studied by differential scanning calorimetry analysis. The results show that variations in both the transition temperature (Tm) and the transition width at half-height of the heat absorption peak (deltaT1/2) were consistent with the antimicrobial activity of the compounds. Penetration kinetics and compression isotherm studies performed with DPPC, DPPG, and E. coli total lipid extract monolayers indicated that both steric hindrance effects and electrostatic forces explained the antimicrobial agent-lipid interaction. Overall, in DPPC monolayers single-chain surfactants had the highest penetration capacity, whereas gemini surfactants were the most active in DPPG systems. The compression isotherms showed an expansion of the monolayers compared with that of pure lipids, indicating an insertion of the compounds into the lipid molecules. Owing to their cationic character, they are incorporated better into the negatively charged DPPG than into zwitterionic DPPC lipid monolayers.

Many byproducts and wastes generated by agroindustries contain polyphenols with potential application as food antioxidants and preventive agents against skin cancer and other diseases. The performance of polyphenolic fractions from Parellada grape (Vitis vinifera) pomace as antioxidants in different physicochemical environments was tested. Fractions containing oligomers with mean degree of polymerization between 3 and 4 and percentage galloylation ca. 30% were the most potent free radical scavengers and efficient antioxidants in an oil-in-water emulsion. A fraction including glycosylated flavonols was also efficient in the emulsion. All the fractions showed low aquatic toxicity and weak influence on proliferation of human melanoma cells.

The condensation reactions between (4-amino-2,6-dichlorophenyl)bis(2, 4,6-trichlorophenyl)methyl radical and acetylacetone or 1, 4-bis(5-methyl-2-thienyl)-1,4-butanedione yield [2,6-dichloro-4-(2, 5-dimethyl-1-pyrrolyl)phenyl]bis(2,4,6-trichlorophenyl)methyl radical (3(*)()) and [2,6-dichloro-4-[2, 5-bis(5-methyl-2-thienyl)-1-pyrrolyl]phenyl]bis(2,4, 6-trichlorophenyl)methyl radical (4(*)()), respectively. EPR studies of both radicals 3(*)() and 4(*)() in CH(2)Cl(2) solution suggest a weak electron delocalization with coupling constant values of 1.25 and 1.30 G, respectively, with the six aromatic hydrogens. Their electrochemical behavior was analyzed by cyclic voltammetry. Both radicals show reversible reduction processes at E degrees = -0.69 V and -0.61 V versus SSCE, respectively, and anodic peak potentials at E(p)(a) = 1.10 and 0.72 V, respectively, versus SSCE at a scan rate (nu) of 200 mV s(-)(1), being reversible for radical 4(*)(). X-ray analysis of radical 3(*)() shows a high value (65 degrees ) of the dihedral angle between the 2,5-dimethylpyrrolidyl moiety and the phenyl ring. Smooth oxidation of radical 4(*)() in CH(2)Cl(2) containing trifluoroacetic acid gives an ionic diradical species with a weak electron interaction (|D/hc| = 0.0047 cm(-)(1)). A Curie plot of the Deltam(s)() = +/-2 signal intensity versus the inverse of the absolute temperature in the range between 4 and 70 K suggests a triplet or a nearly degenerate singlet-triplet ground state.