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A simple and cost-effective laboratory experiment is described that extracts protoporphyrin IX from brown eggshells. The porphyrin is characterized by UV-vis and fluorescence spectroscopy. A chemiluminescence reaction (peroxyoxalate ester fragmentation) is performed that emits light in the UV region. When the porphyrin extract is added as a fluor to this chemiluminescence reaction, an eye-catching deep red glow is emitted from the solution. Using a familiar object, an egg, the experiment touches upon many aspects in chemistry (natural products isolation, structure and photophysical properties of porphyrins, photochemistry). Focus is placed on the understanding of the optical properties of protoporphyrin that enable the final chemiluminescence experiment. This project is appropriate for upper-level organic chemistry students, but might also serve in the advanced physical chemistry laboratory to facilitate a more detailed discussion of photophysical phenomena. Finally, the chemiluminescence experiment is suitable as an impressive stand-alone demonstration. (Contains 1 table, 3 figures, and 2 notes.)

Studies in relation to the silver complexes of porphyrins, corroles and carbaporphyrins are presented especially with relation to silver in the oxidation states II and III. It is seen that the Ag(sub III) complex was electrochemically readily and reversibly reduced to the corresponding Ag(sub II) complex, thus indicating that the complex could be a competent catalyst in electron-transfer reactions.

The synthesis of a series of coumarin-based chemosensor assemblies for zinc is detailed, using established and novel synthetic pathways. The design algorithms for zinc-selective chelation-enhanced fluorescence (CHEF)-type and ratiometric chemosensors are further defined.

Nickel(II) secochlorins, chlorophin and homoporphyrins are examined with reference to their electrochemical properties for the first time.The effect of macrocycle rigidity on electroreduction is presented.

The synthesis and characterization of catecholate complexes of nickel(II) were described with respect to high-spin octahedral and low-spin square-planar complexes. The chemical and physical characteristics as well as the X-ray crystal structures of the nickel catecholates were examined. Experimental results showed that the centrosymmetric octahedral complex is prepared in aqueous solution at low temperature. In contrast, the square-planar complex is formed at higher temperature or under more weakly solvating conditions.

An experiment wherein vic-diol meso-tetraphenyl-2,3-vic-diol-2,3-chlorin is formed via the the osmium tetroxide-mediated dihydroxylation of meso-tetraphenylporphyrin is presented. Lead tetraacetate is used to convert the Ni(II) complex into a (meso-tetraphenyl-2,3-secochlorinato-2,3-dialdehyde)nickel II. Porphyrinoid is then produced by treating the said pigment with methanol.

The Os[O.sub4]-mediated dihydroxylation of meso-tetraphenylporphyrin N-oxide to obtain two regioisomeric chlorin N-oxides is reported. The crystal structure of a free base porpholactone N-oxide carrying the N-oxide on the oxazolone moiety is also reported.

The periodate-induced diol cleavage of meso-tetraphenyl-2,3-diolchlorin has allowed for the generation and isolation of the corresponding hitherto elusive free base secochlorin bisaldehyde. An intramolecular Cannizzaro reaction of the porphyrinoid has generated three pyrrole-modified, oxazole-based porphyrins, and the chromophores in the dimers are coupled electronically.

Fourteen different unialgal xenic diatom cultures isolated from freshwater epilithic biofilms of Lake Constance, Germany, are used to study the composition of diatom-associated bacterial communities. The changes observed in the monomer composition of extracellular polysaccharides of Cymbella microcephala in relation to the presence of different bacteria indicated an adaptation of Proteobacterial and Bacteriodetes to the microenvironment created by the diatom biofilm.

The use of 4-acetylamino-2,2,6,6-tetramethylpiperidine-1-oxoammonium tetrafluoroborate and pyridine for the oxidative dimerization of primary alcohols is explained. It is observed that the alcohols containing beta oxygen are oxidized at a slow rate by oxoammonium salts in acidic media.

A retro-Cope mechanism for the formation of the N-hydroxylamide esters by reaction of dimethyl squarate is introduced as the result of a comparative reactive study. The preliminary iron (III) binding study of the hydroxamic acid demonstrates binding of iron to amides and reflects no effect on the esters.

Research has been conducted on diamagnetic square planar d (super)8 [meso-triarylcorrolato]copper(III) complexes. Results demonstrate that these complexes become paramagnetic upon warming.

Research has been conducted on silver(III) complexes. The authors describe meso-triarylcorrole synthesis and formation of diamagnetic square-planar d (super)8 silver(III) complexes, and demonstrate that spectroscopic properties of [corrolato]-silver(III) complexes are different from those of [porphyrinato]silver(III)

The synthesis, molecular structure and metal-chelating ability of 2-pyrrolythionato complexes of nickel(II), cobalt(III) and mercury(II) are presented. Results show that 2-pyrrolythiones can form stable coordinatively saturated metal complexes with nickel(II), cobalt(III) and mercury(II) and the ligand serves these complexes as a monoanionic bidentate N,S-donor.

Abstract: BACKGROUND: The black soldier fly (Hermetia illucens) is one of the most promising insect species for use in animal feed. However, studies investigating feed and food safety aspects of using black soldier fly as feed are scarce. In this study, we fed black soldier fly larvae feeding media enriched with seaweed, which contains naturally high concentrations of heavy metals and arsenic. The aim of this study was to investigate the potential transfer of such undesirable substances from the feeding media to the larvae. RESULTS: The larvae accumulated cadmium, lead, mercury and arsenic. Concentrations of these elements in the larvae increased when more seaweed was added to the feeding media. The highest retention was seen for cadmium (up to 93%) and the lowest for total arsenic (up to 22%). When seaweed inclusion exceeded 20% in the media, this resulted in larval concentrations of cadmium and total arsenic above the current European Union maximum levels for these elements in complete feed. CONCLUSION: Our results confirm that insect larvae can accumulate heavy metals and arsenic when present in the feeding media. A broader understanding of the occurrence of these undesirable substances in processed larvae products is needed to assess feed and food safety. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: In the past few years, much effort has been invested into developing a new blue economy based on harvesting, cultivating and processing marine macroalgae in Norway. Macroalgae have high potential for a wide range of applications, e.g. as source of pharmaceuticals, production of biofuels or as food and feed. However, data on the chemical composition of macroalgae from Norwegian waters are scant. This study was designed to characterize the chemical composition of 21 algal species. Both macro‐ and micronutrients were analysed. Concentrations of heavy metals and the metalloid arsenic in the algae were also quantified. RESULTS: The results confirm that marine macroalgae contain nutrients which are relevant for both human and animal nutrition, the concentrations whereof are highly dependent on species. Although heavy metals and arsenic were detected in the algae studied, concentrations were mostly below maximum allowed levels set by food and feed legislation in the EU. CONCLUSION: This study provides chemical data on a wide range of algal species covering the three taxonomic groups (brown, red and green algae) and discusses both benefits of and potential limitations to their use for food and feed purposes. © 2017 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In-depth metabolic profiling, also termed metabolomics, provides detailed information about the biochemical phenotype of an organism. Besides improving our understanding of biochemical processes, metabolomics is used for environmental monitoring, natural product discovery, or even chemotaxonomy, among others. However, for marine macroalgae, comparative large-scale metabolomics studies are lacking, even though seaweeds belong to the most important aquatic primary producers. In this study, we present via a broad scale systematic metabolomics survey 391 metabolites from 21 seaweeds species, representing brown, red and green algae. We demonstrate clear differences in metabolite composition of these seaweeds, reflecting their taxonomic classification. We highlight these differences for amino acid, amino acid derivative and peptide metabolites, energy and carbohydrate metabolites, for lipid, fatty acid and sterol metabolites and for secondary metabolites, including selected metabolic pathways such as the urea cycle, the citrate cycle and the glyconeogenesis/glycolysis, besides others. Additionally, we link selected seaweed biochemical properties to potential pharmaceutical and nutraceutical applications. [ABSTRACT FROM AUTHOR]

Black soldier fly (Hermetia illucens) larvae are a promising source of protein and lipid for animal feeds. The nutritional composition of the BSF larvae depend partly on the composition of the feeding medium. The BSF lipid profile in part mimics the feeding media lipid profile, and micronutrients, like minerals and vitamins, can readily accumulate in black soldier fly larvae. However, investigative studies on bioconversion and accumulation of nutrients from media to black soldier fly larvae are scarce. Here we show that inclusion of the brown algae Ascophyllum nodosum in the substrate for black soldier fly larvae can introduce valuable nutrients, commonly associated with the marine environment, into the larvae. The omega-3 fatty acid eicosapentaenoic acid (20:5n-3), iodine and vitamin E concentrations increased in the larvae when more seaweed was included in the diet. When the feeding media consisted of more than 50% seaweed, the larvae experienced poorer growth, lower nutrient retention and lower lipid levels, compared to a pure plant based feeding medium. Our results confirm the plasticity of the nutritional make-up of black soldier fly larvae, allowing it to accumulate both lipid- and water-soluble compounds. A broader understanding of the effect of the composition of the feeding media on the larvae composition can help to tailor black soldier fly larvae into a nutrient profile more suited for specific feed or food purposes. [ABSTRACT FROM AUTHOR]

The X-ray crystal structure of the secochlorinato nickel, a metallochlorin-like pigment derived from meso-tetraphenylporphyrinato nickel by cleavage of one peripheral beta,beta'-double bond, is described. The synthesis and stepwise decarbonylation of porphyrins were performed for this purpose. Experimental results showed the growth of crystals that are suitable for an X-ray crystal structure characterization. The crystal structures of meso-tetraphenylchlorophinato nickel(II) and meso-tetraphenylsecochlorinato nickel(II) also revealed that both compounds exist in seriously ruffled conformations comparable to that of the nonplanar homoporphyrin.

Tetrahedral M4L4 and M4L6 supramolecular clusters were designed and their properties investigated.

In this study, we describe different combinations of physical separation and antibiotic treatment to remove associated bacteria from freshwater diatoms. Diatoms were purified either from natural epilithic biofilms or from unialgal cultures. We determined that for most strains, different purification procedures have to be combined individually. In a new approach, we show that for some diatom strains, the substitution of associated aquatic bacteria by an antibiotic-sensitive Escherichia coli strain and subsequent treatment with antibiotics may be a successful strategy to obtain axenic diatom cultures. Axenic diatom cultures are essential to study the physiology and biochemistry of individual strains as well as their responses to environmental changes without interference of accompanying bacteria. [ABSTRACT FROM AUTHOR]

Investigates the design, formation and properties of tetrahedral supramolecular clusters of type M[sub 4]L[sub 4] and M[sub 4]L[sub 6]. Synthesis and analysis of metal-ligand based clusters; Solution and solid-state characterization of complexes; Thermodynamic implications of ligand rigidity.

Review: 51 refs. [ABSTRACT FROM AUTHOR]

Background: The black soldier fly (Hermetia illucens) is one of the most promising insect species for use in animal feed. However, studies investigating feed and food safety aspects of using black soldier fly as feed are scarce. In this study, we fed black soldier fly larvae feeding media enriched with seaweed, which contains naturally high concentrations of heavy metals and arsenic. The aim of this study was to investigate the potential transfer of such undesirable substances from the feeding media to the larvae., Results: The larvae accumulated cadmium, lead, mercury and arsenic. Concentrations of these elements in the larvae increased when more seaweed was added to the feeding media. The highest retention was seen for cadmium (up to 93%) and the lowest for total arsenic (up to 22%). When seaweed inclusion exceeded 20% in the media, this resulted in larval concentrations of cadmium and total arsenic above the current European Union maximum levels for these elements in complete feed., Conclusion: Our results confirm that insect larvae can accumulate heavy metals and arsenic when present in the feeding media. A broader understanding of the occurrence of these undesirable substances in processed larvae products is needed to assess feed and food safety. © 2017 Society of Chemical Industry., (© 2017 Society of Chemical Industry.)

Background: In the past few years, much effort has been invested into developing a new blue economy based on harvesting, cultivating and processing marine macroalgae in Norway. Macroalgae have high potential for a wide range of applications, e.g. as source of pharmaceuticals, production of biofuels or as food and feed. However, data on the chemical composition of macroalgae from Norwegian waters are scant. This study was designed to characterize the chemical composition of 21 algal species. Both macro- and micronutrients were analysed. Concentrations of heavy metals and the metalloid arsenic in the algae were also quantified., Results: The results confirm that marine macroalgae contain nutrients which are relevant for both human and animal nutrition, the concentrations whereof are highly dependent on species. Although heavy metals and arsenic were detected in the algae studied, concentrations were mostly below maximum allowed levels set by food and feed legislation in the EU., Conclusion: This study provides chemical data on a wide range of algal species covering the three taxonomic groups (brown, red and green algae) and discusses both benefits of and potential limitations to their use for food and feed purposes. © 2017 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., (© 2017 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.)