Synthesis, Characterization, And Catalytic And Biological Activities of A Mixed-ligand Cobalt(ii) Bipyridyl/diphenylazodioxide Complex

Transition metal complexes have immense importance in the pharmaceutical industry. These types of complexes can be useful catalysts in the synthesis of medicinal compounds and can act as anticancer drugs. In these pharmaceutical applications, 1st-row transition metal-containing complexes offer certain advantages compared to their 2nd and 3rd-row transition metal counterparts. Our motivation was to investigate pharmaceutical applications of transition metal complexes containing both a 1st-row transition metal and unusual ligands to expand the knowledge of a class of complexes that could potentially be beneficial in the pharmaceutical industry. A class of rare ligands that piqued our interest was that of the diaryl azodioxides, cis-Ar(O)NN(O)Ar, which belong to the wider class of organic derivatives of nitric oxide (NO). Our synthesis and pharmaceutical applications of the azodioxide complex salt [Co(bpy){Ph(O)NN(O)Ph}2](PF6)2 have been able to significantly expand the knowledge of azodioxide complexes by displaying an unusual trigonal prismatic coordination geometry for cobalt(II) with only bidentate ligands, showing evidence of ligand-based redox activity, acting as an active catalyst in allylic amination/C-C double-bond transposition reactions, and selectively inducing apoptosis in SK-HEP-1 human liver adenocarcinoma cells. Importantly, catalytic and biological studies of [Co(bpy){Ph(O)NN(O)Ph}2](PF6)2 are ongoing, and focused on its potential for use in the pharmaceutical industry as a drug or catalyst for drug synthesis. Future work will vi involve comparing the catalytic and biological activities of [Co(bpy){Ph(O)NN(O)Ph}2](PF6)2 with other azodioxide complexes prepared by our group to identify structure-activity relationships and inform the design of more efficient catalysts and anti-cancer, pro-apoptotic agents

Persistent organic pollutants in the Atlantic and southern oceans and oceanic atmosphere

Persistent organic pollutants (POPs) continue to cycle through the atmosphere and hydrosphere despite banned or severely restricted usages. Global scale analyses of POPs are challenging, but knowledge of the current distribution of these compounds is needed to understand the movement and long-term consequences of their global use. In the current study, air and seawater samples were collected Oct. 2007–Jan. 2008 aboard the Icebreaker Oden en route from Göteborg, Sweden to McMurdo Station, Antarctica. Both air and surface seawater samples consistently contained α-hexachlorocyclohexane (α-HCH), γ-HCH, hexachlorobenzene (HCB), α-Endosulfan, and polychlorinated biphenyls (PCBs). Sample concentrations for most POPs in air were higher in the northern hemisphere with the exception of HCB, which had high gas phase concentrations in the northern and southern latitudes and low concentrations near the equator. South Atlantic and Southern Ocean seawater had a high ratio of α-HCH to γ-HCH, indicating persisting levels from technical grade sources. The Atlantic and Southern Ocean continue to be net sinks for atmospheric α-, γ-HCH, and Endosulfan despite declining usage

A new monotypic family for the enigmatic crustose red alga Plagiospora gracilis.

Plagiospora gracilis, a mucilaginous crustose red alga growing on subtidal pebbles on both coasts of the North Atlantic Ocean, forms distinctive tetrasporangia (red algal meiotic structures that release haploid tetraspores) but gametophytes have never been reported. In the absence of gametangia, the taxonomic position of this monotypic genus has always been uncertain; it is currently placed provisionally in the Gloiosiphoniaceae (Gigartinales) by comparison with sporophytes of Gloiosiphonia obtained in culture. Dioecious gametophytic crusts of P. gracilis are now reported for the first time, forming gametangia in inconspicuous superficial sori. There is no evidence that fertilization ever occurs in the field although fertile males and female were collected together. In culture, tetraspores grew into tetrasporophytes for three successive generations, by presumed apomictic sporophyte recycling. The life history of P. gracilis may represent a late stage in the loss of sexual reproduction leading to tetraspore-to-tetrasporophyte life histories such as that in Hildenbrandia. Phylogenetic analysis of sequences of the rbcL, LSU (28S) rDNA and coxI (COI-5P) genes for P. gracilis with other Gigartinales resolved P. gracilis as a distinct lineage in a well-supported clade of the families Sphaerococcaceae, Gloiosiphoniaceae, Endocladiaceae, Nizymeniaceae and Phacelocarpaceae. We here propose the monotypic Plagiosporaceae fam. nov. to accommodate P. gracilis

Allylic Amination and Carbon–carbon Double Bond Transposition Catalyzed by Cobalt(II) azodioxide Complexes

The unusual cobalt(II) diphenylazodioxide complex salts [Co(az)4](PF6)2 and [Co(bpy)(az)2](PF6)2 have been shown to catalyze the allylic amination/C–C double bond transposition reaction of 2-methyl-2-pentene with PhNHOH, with a turnover number of about 4. The mechanism is proposed to involve a nitroso-ene-like transfer of a PhNO moiety from the azodioxide ligand to the alkene, followed by reduction of the organic product to yield a cobalt(III) intermediate, which is itself reduced back to cobalt(II) by PhNHOH, regenerating PhNO. Hetero-Diels-Alder trapping experiments suggest that an “off-metal” mechanism, in which PhNO is released from the cobalt complexes and reacts with the alkenes, is operative, in contrast to an “on-metal” mechanism observed by Nicholas and coworkers for [Fe(az)3](FeCl4)2

Multigene analyses resolve early diverging lineages in the Rhodymeniophycidae (Florideophyceae, Rhodophyta).

Multigene phylogenetic analyses were directed at resolving the earliest divergences in the red algal subclass Rhodymeniophycidae. The inclusion of key taxa (new to science and/or previously lacking molecular data), additional sequence data (SSU, LSU, EF2, rbcL, COI-5P), and phylogenetic analyses removing the most variable sites (site stripping) have provided resolution for the first time at these deep nodes. The earliest diverging lineage within the subclass was the enigmatic Catenellopsis oligarthra from New Zealand (Catenellopsidaceae), which is here placed in the Catenellopsidales ord. nov. In our analyses Atractophora hypnoides was not allied with the other included Bonnemaisoniales, but resolved as sister to the Peyssonneliales, and is here assigned to Atractophoraceae fam. nov. in the Atractophorales ord. nov. Inclusion of Acrothesaurum gemellifilum gen. et sp. nov. from Tasmania has greatly improved our understanding of the Acrosymphytales, to which we assign three families, the Acrosymphytaceae, Acrothesauraceae fam. nov. and Schimmelmanniaceae fam. nov. This article is protected by copyright. All rights reserved

Cobalt(II) Diphenylazodioxide Complexes Induce Apoptosis in SK-HEP-1 Cells

The cobalt(II) complex salts [Co(bpy)(az)2](PF6)2 and [Co(az)4](PF6), each bearing the unusual cis-N,N\u27-diphenylazodioxide ligand, were both screened as possible anticancer agents against SK-HEP-1 liver cancer cells. Both compounds were found to induce substantial apoptosis as an increasing function of concentration and time. Measurement of apoptosis-related proteins indicated that both the extrinsic and intrinsic pathways of apoptosis were activated. The apoptotic activity induced by these salts is not displayed either by simple cobalt(II) salts or complexes or by the free nitrosobenzene ligand. Additionally, these compounds did not induce apoptosis, as assessed by poly(adenosine diphosphate-ribose) polymerase cleavage, in several other cell lines

Cobalt(II) Diphenylazodioxide Complexes Induce Apoptosis in SK-HEP-1 Cells

The cobalt(II) complex salts [Co(bpy)(az)2](PF6)2 and [Co(az)4](PF6), each bearing the unusual cis-N,N\u27-diphenylazodioxide ligand, were both screened as possible anticancer agents against SK-HEP-1 liver cancer cells. Both compounds were found to induce substantial apoptosis as an increasing function of concentration and time. Measurement of apoptosis-related proteins indicated that both the extrinsic and intrinsic pathways of apoptosis were activated. The apoptotic activity induced by these salts is not displayed either by simple cobalt(II) salts or complexes or by the free nitrosobenzene ligand. Additionally, these compounds did not induce apoptosis, as assessed by poly(adenosine diphosphate-ribose) polymerase cleavage, in several other cell lines

Electrochemical Studies of Cobalt(II) diphenylazodioxide Complexes

The electrochemical behavior of the unusual cobalt(II) diphenylazodioxide complex salts [Co(az)4](PF6)2 1 and [Co(bpy)(az)2](PF6)2 2 has been studied by cyclic voltammetry. Each complex displays two quasireversible redox couples, which are proposed to correspond to a reduction of Co(II) to Co(I), followed by a ligand-based reduction. Irreversible reductions of 1 are observed at more negative potentials, and are proposed to arise from deposition of elemental Co and the decomposition of transiently formed Co(-I) species. Spectroelectrochemical experiments on both 1 and 2, involving electrolytic reduction followed by reoxidation, are consistent with the quasireversibility observed in the CV measurements

THE GENUS HYPOGLOSSUM KÜTZING (DELESSERIACEAE, RHODOPHYTA) IN THE TROPICAL WESTERN ATLANTIC, INCLUDING H. ANOMALUM SP. NOV. 1

Observations are made on the occurrence and distribution of the red algal genus Hypoglossum KÜtzing (Delesseriaceae, Ceramiales) in the tropical western Atlantic. In addition to the type of the genus, H. hypoglossoides (Stackh.) Coll. & Herv., three other species are reported: H. anomalum sp. nov., H. involvens (Harv.) J. Ag., and H. tenuifolium (Harv.) J. Ag. A key is presented to distinguish these four species. The newly described species, H. anomalum, is like other species in the genus in that its branches arise endogenously from the primary axial row but it is unique in that the branches emerge from the parent blade at some point between the midline and the margin of the blade. The new species is reported from Puerto Rico and Florida.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65648/1/j.1529-8817.1986.tb04162.x.pd