DOPA peptidomimetics with stable O-C and N-C covalent bonds between amino acid residues have been prepared by aromatic oxidative functionalization of tyrosine with 2-iodoxybenzoic acid (IBX). The reaction involves the Michael-like nucleophilic addition of different oxygen and nitrogen protected amino acids on a reactive DOPA quinone intermediate. Similar results were obtained in heterogeneous conditions using supported IBX-amide for more runs. Among the novel derivatives, compounds containing glycine residues showed a more pronounced antioxidant activity in the 2,2-diphenyl picrylhydrazyl (DPPH) radical scavenging cell free assay. Instead, valine derivatives showed the highest biological effect in L5178Y mouse lymphoma cells, by assessing the ability to reduce H 2 O 2 induced DNA breakage in the alkaline comet assay. a Reaction conditions: compound 1 (0.1 mmol) was dissolved in THF (1.5 mL) in the presence of the appropriate protected a-amino acids 2-9 (1.0 mmol) and treated with IBX (0.3 mmol) at 45 C for 72 h. b Reaction performed at 25 C for 3 h. This journal is View Article Online a Reaction conditions: compound 1 (0.1 mmol) was dissolved in the appropriate solvent (1.5 mL) in the presence of protected a-amino acids 19-26 (1.0 mmol) and treated with IBX (0.3 mmol) at 45 C for 72 h. 60356 | RSC Adv., 2015, 5, 60354-60364 This journal is

Potentiometric titrations and (1) H NMR spectroscopic studies of amino acids binding to the [ZnL](2+) -complex where L=cyclen in aqueous solution provide information concerning complexing species identity, their stability, and coordination mode declaration. The amino acids form stable ternary [ZnL(HL(n))](2+) and [ZnL(L(n))](+) complexes. The observations indicate bidentate coordination mode of the deprotonated amino acids, involving both the amine and the carboxylate functions to the [ZnL](2+) complex in pH region of about 7.5-9.5. The determined stability constants indicate that [ZnL](2+) complex is a very efficient receptor for simple amino acids such as glycine and alanine.

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MNMs which consume chemical fuel and move by bubble propulsion and also have magnetic properties and can propel by applying a magnetic field. These engines can reduce the common fuel used in chemical engines by applying magnetic driving force and switching their operation in response to changing conditions. Due to continuous innovations in this field, MNMs will profoundly impact the field of Nanorobotics.

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The reactions products of tertiary arsines with methylene iodide are (iodomethyl)trialkyl(aryl)-arsonium iodides. Treatment of the latter with lead(II) nitrate in aqueous ethanol solutions gives rise to an exchange reaction to form the corresponding nitrates in high yields.Tertiary arsines, both symmetrical and mixedradical, react with organyl halides to give tertiary arsonium salts [1]. The fourth bond is formed by coordination of antibonding 4s 2 electrons of trivalent arsenic with trivalent Lewis acids. As a result, cationic complexes are formed [2]. Nucleophilic properties of trialkyl(aryl)arsines depend not only on the existence of the above-mentioned electron pair, but also on the character of substituents on the central atom, and, what is most important, on the composition and structure of the electrophilic reagent, that is organyl halide [3].Michaelis [4] has been the first to show that triphenylarsine is alkylated with diiodomethane at 130oC to form an adduct with the following proposed composition and structure.(C 6 H 5 ) 3 As E A CH 2 I I From this structure it follows that the arsenic atom in it, as well as in all other five-coordinate arsenic compounds should be sp 3 d-hybridized, and the geometry of the product should be trigonal bipyramid [5]. No more recent data on the alkylation with methylene iodide of other trialkyl(aryl)arsines are available.To gain more information on the ability of diiodomethane to exhibit electrophilic properties in reaction with tertiary arsines of various compositions and structures, as well as to assess the structure of the reaction products, in the present work we performed a more thorough study of the reaction of trialkyl(aryl)-arsines with methylene iodide.It was found that methylene iodide reacts with tertiary arsines, including those with mixed radicals, to form tertiary arsonium iodides IIa3IIh [reactions (1) and (2)].