Quality of cellulose and biostimulant extracts from Oedogonium calcareum cultivated during primary wastewater treatment.

A practical two-product cascading biorefinery was developed to extract a biostimulant and cellulose from the freshwater filamentous macroalga Oedogonium calcareum grown while treating primary wastewater. Biostimulant production provides a valuable extract with production of disinfected residual biomass for further product development. Both Escherichia coli and F-specific RNA bacteriophage, indicators of human pathogens contamination, were absent from the residual biomass.

Ulvans are not equal - Linkage and substitution patterns in ulvan polysaccharides differ with Ulva morphology.

Ulva are hardy green seaweeds that contain the sulfated polysaccharide ulvan and grow in two distinct morphologies: foliose and tubular. The authors hypothesise that ulvan from tubular species are more structurally complex than ulvans from foliose species. Herein, using standardised methods, the glycosyl linkage positions and sulfate ester substitutions of constituent monosaccharides of ulvan isolated from foliose (U.

High spatial and temporal variation in biomass composition of the novel aquaculture target .

Unlabelled: The biomass composition of kelp varies within species both spatially and temporally. However, this variation in biomass quality has not yet been investigated for the native kelp within New Zealand, where the kelp is a target for the emerging seaweed aquaculture industry. In this study we quantified spatial and temporal variation in the composition of biomass, collected from 12 sites around the North Island of New Zealand and from 12 months across a full year at a single site ( = 138).

The Algal Polysaccharide Ulvan and Carotenoid Astaxanthin Both Positively Modulate Gut Microbiota in Mice.

The intestinal microbial community (microbiota) is dynamic and variable amongst individuals and plays an essential part in gut health and homeostasis. Dietary components can modulate the structure of the gut microbiota. In recent years, substantial efforts have been made to find novel dietary components with positive effects on the gut microbial community structure.

Structural characterization of ulvans extracted from blade (Ulva ohnoi) and filamentous (Ulva tepida and Ulva prolifera) species of cultivated Ulva.

Ulvans from Ulva ohnoi, Ulva tepida and Ulva prolifera were extracted under mild acidic conditions, isolated and their composition and structure determined. The ulvans contained mostly rhamnose (31.6-46.

Brown Seaweed as an Intervention for Diet-Induced Obesity in Male Wistar Rats.

The therapeutic potential of grown in Australian tropical waters was tested in a rat model of metabolic syndrome. Forty-eight male Wistar rats were divided into four groups of 12 rats and each group was fed a different diet for 16 weeks: corn starch diet (C); high-carbohydrate, high-fat diet (H) containing fructose, sucrose, saturated and fats; and C or H diets with 5% mixed into the food from weeks 9 to 16 (CS and HS). Obesity, hypertension, dyslipidaemia, impaired glucose tolerance, fatty liver and left ventricular fibrosis developed in H rats.

Are all ulvans equal? A comparative assessment of the chemical and gelling properties of ulvan from blade and filamentous Ulva.

Green seaweeds of the genus Ulva are rich in the bioactive sulfated polysaccharide ulvan. Herein we characterise ulvan from Ulva species collected from the Bay of Plenty, Aotearoa New Zealand. Using standardised procedures, we quantified, characterised, and compared ulvans from blade (U.

The molecular weight of ulvan affects the in vitro inflammatory response of a murine macrophage.

Ulvan, a sulfated polysaccharide extracted from the green seaweed genus Ulva, has bioactive properties including an immunomodulating capacity. The immunomodulatory capacity of ulvan from Ulva ohnoi, however, has not been assessed in detail. We depolymerised purified ulvan from U.

Post-Assembly Covalent Di- and Tetracapping of a Dinuclear [Fe2L3](4+) Triple Helicate and Two [Fe4L6](8+) Tetrahedra Using Sequential Reductive Aminations.

The use of a highly efficient reductive amination procedure for the postsynthetic end-capping of metal-templated helicate and tetrahedral supramolecular structures bearing terminal aldehyde groups is reported. Metal template formation of a [Fe2L3](4+) dinuclear helicate and two [Fe4L6](8+) tetrahedra (where L is a linear ligand incorporating two bipyridine domains separated by one or two 1,4-(2,5-dimethoxyaryl) linkers and terminated by salicylaldehyde functions is described. Postassembly reaction of each of these "open" di- and tetranuclear species with excess ammonium acetate (as a source of ammonia) and sodium cyanoborohydride results in a remarkable reaction sequence whereby the three aldehyde groups terminating each end of the helicate, or each of the four vertices of the respective tetrahedra, react with ammonia then undergo successive reductive amination to yield corresponding fully tertiary-amine capped cryptate and tetrahedral covalent cages.

Controlling ground and excited state properties through ligand changes in ruthenium polypyridyl complexes.

The capture and storage of solar energy requires chromophores that absorb light throughout the solar spectrum. We report here the synthesis, characterization, electrochemical, and photophysical properties of a series of Ru(II) polypyridyl complexes of the type [Ru(bpy)2(N-N)](2+) (bpy = 2,2'-bipyridine; N-N is a bidentate polypyridyl ligand). In this series, the nature of the N-N ligand was altered, either through increased conjugation or incorporation of noncoordinating heteroatoms, as a way to use ligand electronic properties to tune redox potentials, absorption spectra, emission spectra, and excited state energies and lifetimes.

Synthesis of phosphonic acid derivatized bipyridine ligands and their ruthenium complexes.

Water-stable, surface-bound chromophores, catalysts, and assemblies are an essential element in dye-sensitized photoelectrosynthesis cells for the generation of solar fuels by water splitting and CO2 reduction to CO, other oxygenates, or hydrocarbons. Phosphonic acid derivatives provide a basis for stable chemical binding on metal oxide surfaces. We report here the efficient synthesis of 4,4'-bis(diethylphosphonomethyl)-2,2'-bipyridine and 4,4'-bis(diethylphosphonate)-2,2'-bipyridine, as well as the mono-, bis-, and tris-substituted ruthenium complexes, [Ru(bpy)2(Pbpy)](2+), [Ru(bpy)(Pbpy)2](2+), [Ru(Pbpy)3](2+), [Ru(bpy)2(CPbpy)](2+), [Ru(bpy)(CPbpy)2](2+), and [Ru(CPbpy)3](2+) [bpy = 2,2'-bipyridine; Pbpy = 4,4'-bis(phosphonic acid)-2,2'-bipyridine; CPbpy = 4,4'-bis(methylphosphonic acid)-2,2'-bipyridine].

Electrogenerated polypyridyl ruthenium hydride and ligand activation for water reduction to hydrogen and acetone to iso-propanol.

The complex [Ru(tpy)(bpy)(S)](2+) (tpy = 2,2':6',2''-terpyridine, bpy = 2,2'-bipyridine, S = solvent) is an electrocatalyst for water or proton reduction to hydrogen and for reduction of acetone to iso-propanol in CH3CN. Electrocatalysis is initiated by sequential 1e(-) reductions at the tpy and bpy ligands followed by addition of water to give a ruthenium hydride intermediate. Significant rate enhancements for hydrogen evolution are observed with added weak acids, such as H2PO4(-), for the latter, with a rate enhancement of 10(4) compared to water.

Photoinduced electron transfer in a chromophore-catalyst assembly anchored to TiO2.

Photoinduced formation, separation, and buildup of multiple redox equivalents are an integral part of cycles for producing solar fuels in dye-sensitized photoelectrosynthesis cells (DSPECs). Excitation wavelength-dependent electron injection, intra-assembly electron transfer, and pH-dependent back electron transfer on TiO(2) were investigated for the molecular assembly [((PO(3)H(2)-CH(2))-bpy)(2)Ru(a)(bpy-NH-CO-trpy)Ru(b)(bpy)(OH(2))](4+) ([TiO(2)-Ru(a)(II)-Ru(b)(II)-OH(2)](4+); ((PO(3)H(2)-CH(2))(2)-bpy = ([2,2'-bipyridine]-4,4'-diylbis(methylene))diphosphonic acid); bpy-ph-NH-CO-trpy = 4-([2,2':6',2″-terpyridin]-4'-yl)-N-((4'-methyl-[2,2'-bipyridin]-4-yl)methyl) benzamide); bpy = 2,2'-bipyridine). This assembly combines a light-harvesting chromophore and a water oxidation catalyst linked by a synthetically flexible saturated bridge designed to enable long-lived charge-separated states.

Sensitized photodecomposition of organic bisphosphonates by singlet oxygen.

During efforts to stabilize metal oxide bound chromophores for photoelectrochemical applications, a novel photochemical reaction has been discovered. In the reaction, the bisphosphonate functional groups -C(PO(3)H(2))(2)(OH) in the metal complex [Ru(bpy)(2)(4,4'-(C(OH)(PO(3)H(2))(2)bpy)](2+) are converted into -COOH and H(3)PO(4). The reaction occurs by sensitized formation of (1)O(2) by the lowest metal-to-ligand charge transfer excited state(s) of [Ru(bpy)(2)(4,4'-(C(PO(3)H(2))(2)(OH))(2)(bpy))](2+)* followed by (1)O(2) oxidation of the bisphosphonate substituent.

Self-assembled bilayers on indium-tin oxide (SAB-ITO) electrodes: a design for chromophore-catalyst photoanodes.

A novel approach for creating assemblies on metal oxide surfaces via the addition of a catalyst overlayer on a chomophore monolayer derivatized surface is described. It is based on the sequential self-assembly of a chromophore, [Ru(bpy)(4,4'-(PO(3)H(2)bpy)(2))](2+), and oxidation catalyst, [Ru(bpy)(P(2)Mebim(2)py)OH(2)](2+), pair, resulting in a spatially separated chromophore-catalyst assembly.

Interfacial dynamics and solar fuel formation in dye-sensitized photoelectrosynthesis cells.

Dye-sensitized photoelectrosynthesis cells (DSPECs) represent a promising approach to solar fuels with solar-energy storage in chemical bonds. The targets are water splitting and carbon dioxide reduction by water to CO, other oxygenates, or hydrocarbons. DSPECs are based on dye-sensitized solar cells (DSSCs) but with photoexcitation driving physically separated solar fuel half reactions.

Photostability of phosphonate-derivatized, Ru(II) polypyridyl complexes on metal oxide surfaces.

The photostability of [Ru(II)(bpy)(2)(4,4'-(PO(3)H(2))(2)bpy)]Cl(2) (bpy = 4,4'-bipyridine) on nanocrystalline TiO(2) and ZrO(2) films was investigated using a standard measurement protocol. Stability was evaluated by monitoring visible light absorbance spectral changes, in real time, during 455 nm photolysis (30 nm fwhm, 475 mW/cm(2)) in a variety of conditions relevant to dye-sensitized solar cells and dye-sensitized photoelectrosynthesis cells. Desorption (k(des)) and photochemical (k(chem)) processes were observed and found to be dependent upon solvent, anion, semiconductor, and presence of oxygen.

Nickel(II) and iron(II) triple helicates assembled from expanded quaterpyridines incorporating flexible linkages.

In the present study the interaction of Fe(II) and Ni(II) with the related expanded quaterpyridines, 1,2-, 1,3- and 1,4-bis-(5'-methyl-[2,2']bipyridinyl-5-ylmethoxy)benzene ligands (4-6 respectively), incorporating flexible, bis-aryl/methylene ether linkages in the bridges between the dipyridyl domains, was shown to predominantly result in the assembly of [M(2)L(3)](4+) complexes; although with 4 and 6 there was also evidence for the (minor) formation of the corresponding [M(4)L(6)](8+) species. Overall, this result contrasts with the behaviour of the essentially rigid 'parent' quaterpyridine 1 for which only tetrahedral [M(4)L(6)](8+) cage species were observed when reacted with various Fe(II) salts. It also contrasts with that observed for 2 and 3 incorporating essentially rigid substituted phenylene and biphenylene bridges between the dipyridyl domains where reaction with Fe(II) and Ni(II) yielded both [M(2)L(3)](4+) and [M(4)L(6)](8+) complex types, but in this case it was the latter species that was assigned as the thermodynamically favoured product type.

New nickel(II) and iron(II) helicates and tetrahedra derived from expanded quaterpyridines.

As an extension of prior studies involving the linear quaterpyridine ligand, 5,5'''-dimethyl-2,2':5',5'':2'',2'''-quaterpyridine 1, the synthesis of the related expanded quaterpyridine derivatives 2 and 3 incorporating dimethoxy-substituted 1,4-phenylene and tetramethoxy-substituted 4,4'-biphenylene bridges between pairs of 2,2'-bipyridyl groups has been carried out via double-Suzuki coupling reactions between 5-bromo-5'-methyl-2'-bipyridine and the appropriate di-pinacol-diboronic esters using microwave heating. Reaction of 2 and 3 with selected Fe(II) or Ni(II) salts yields a mixture of both [M(2)L(3)](4+) triple helicates and [M(4)L(6)](8+) tetrahedra, in particular cases the ratio of the products formed was shown to be dependent on the reaction conditions; the respective products are all sufficiently inert to allow their chromatographic separation and isolation. Longer reaction times and higher concentrations were found to favour tetrahedron formation.

A new FeII quaterpyridyl M4L6 tetrahedron exhibiting selective anion binding.

A rigid linear bis-bidentate quaterpyridine undergoes metal directed self-assembly with iron(ii) salts yielding M(4)L(6) host-guest complexes; selective anion binding for PF(6)(-) over BF(4)(-) is observed.

5,5'-Bis[(trimethyl-silyl)meth-yl]-2,2'-bipyridine.

The mol-ecule of the title compound, C(18)H(28)N(2)Si(2), occupies a special position on an inversion centre. The Si-CH(2)-C(ipso) plane is approximately orthogonal to the plane of the pyridine rings, the corresponding dihedral angle being 82.0 (2)°.