About biological reaction to arsenic

-Only rarely are green plumage colors due to the presence of green pigments. The best known is turacoverdin. Two galliform species (Ithaginis, Rollolus), Jacana and some anseriform species (Somateria, Nettapus) also have green pigments. The reflectance spectra of plumage pigmented by turacoverdin are characterized by distinct minima at about 570 and 610 nm. These minima represent absorption bands as confirmed by a transmittance spectrum of a turacoverdin extract. Surprisingly, the spectra of the two galliform species and Jacana also exhibit the characteristics of the turacoverdin spectrum, while that of Somateria is different. I show that the pigments of Ithaginis, Rollolus, and Jacana also resemble turacoverdin in containing copper in relatively high concentration, and conclude that these pigments are identical with or closely related to turacoverdin. Intraand interspecific variation in reflectance spectra is assumed to be largely determined by the presence of dark, nongreen pigments in the plumage. The spectrum of turacoverdin supports the hypothesis that the pigment is closely related to the well-known red pigment of turacos (Musophagidae)-turacin. However, the chemical constitution of turacoverdin remains unknown. The presence of turacoverdin and turacin in the plumage of the Musophagidae hitherto has been considered an autapomorphy of the turacos. The fact the turacoverdin also is present in two possibly related galliform taxa argues for phylogenetic relationships between the Musophagidae and the Galliformes. Received 3 April 1991, accepted 10 January 1992. GREEN, noniridescent plumage colors can be produced in a number of ways (Auber 1957). The combination of a structural blue color with yellow pigments, as found in parrots, is best known (Frank 1939, Dyck 1971). The olive-green colors obtained by the juxtaposition of yellow and blackish pigments (apposition colors; Auber 1957, Dyck 1978) also are widespread. Central to my two studies is the question of the evolution of plumage colors that resemble the green colors of leaves, without chlorophyll being available as a feather pigment (Needham 1974:81). In principle, the simplest way to produce a green plumage color is to deposit a green pigment within the feather keratin. This possibility has been realized in only a limited number of cases. The best-known green feather pigment is turacoverdin. This is found in some turacos (Musophagidae), especially the species of Tauraco and Musophaga, and possibly also in the Great Blue Turaco (Corythaeola cristata; Krukenberg 1882, Moreau 1958). Preliminary chemical studies have been carried out (Moreau 1958). Other known green pigments are zooprasinin in the remiges of the Jacana (Jacana spinosa, Jacanidae; Rensch 1925), phasianoverdin in belly feathers of the Blood Pheasant (Ithaginis cruentus, Phasianidae; Gotz 1925), and a green pigment in much of the plumage of the Roulroul (Crested Wood-Partridge, Rollolus roulroul, Phasianidae), especially the female (Volker 1961). The green pigments in some anseriform species (Nettapus, Somateria; Auber 1957) are poorly known (Brush 1978). I describe the reflectance spectra of green plumage areas in several species and discuss factors that influence the shapes of the spectra. I compare the reflectance spectra with the spectrum of turacoverdin in extract and from this infer the probable identity of some of the pigments. MATERIALS AND METHODS Most measurements were performed on study skins from the Zoological Museum, University of Copenhagen, and the British Museum (Natural History). A few measurements were also carried out on mounted specimens. The spectrum of the nape of an adult male Eider (Somateria mollissima) was scanned on feathers taken from a newly dead bird. Feathers plucked from live birds were obtained from the Zoological Garden, Copenhagen, and kept four months in the dark before measurement. Reflectance spectra were obtained on a Beckman DK-2A spectrophotometer with a reflectance attachment and using a reference of magnesium oxide. The illuminated spot was approximately 8 x 8 mm.

Selective paint coatings for coloured solar absorbers: Polyurethane thickness insensitive spectrally selective (TISS) paints (Part II)

Visible Sympathetic Activity as a Social Signal in Anolis carolinensis: Changes in Aggression and Plasma Catecholamines

Synthesis and characterization of cobalt doped green ceramic pigment from tannery sludge

Amino acid changes S180A (S-->A at site 180), H197Y, Y277F, T285A, and A308S are known to shift the maximum wavelength of absorption (lambda max) of red and green visual pigments toward blue, essentially in an additive fashion. To test the generality of this "five-sites" rule, we have determined the partial amino acid sequences of red and green pigments from five mammalian orders (Artiodactyla, Carnivora, Lagomorpha, Perissodactyla, and Rodentia). The result suggests that cat (Felis catus), dog (Canis familiaris), and goat (Capra hircus) pigments all with AHYTA at the five critical sites have lambda max values of approximately 530 nm, whereas rat (Rattus norvegicus) pigment with AYYTS has a lambda max value of approximately 510 nm, which is accurately predicted by the five-sites rule. However, the observed lambda max values of the orthologous pigments of European rabbit (Oryctolagus cuniculus), white-tailed deer (Odocoileus virginianus), gray squirrel (Sciurus carolinensis), and guinea pig (Cavia procellus) are consistently more than 10 nm higher than the predicted values, suggesting the existence of additional molecular mechanisms for red and green color vision. The inferred amino acid sequences of ancestral organisms suggest that the extant mammalian red and green pigments appear to have evolved from a single ancestral green-red hybrid pigment by directed amino acid substitutions.

Green pigments of Roman mural paintings from Seville Alcazar

Oyster, Crassostera gigas, from the coast of Hiroshima occasionally becomes green after being canned, and the phenomenon makes a trouble for the quality control of the products. The color usually develops around the digestive diverticula of the body, and the situation completely differs from those caused by such pollutants as heavy metals which makes the oyster also green. As the appearance of green oyster changes seasonally, a relationship was expected between the standing crops of dietary phytoplankton and the greening of the oyster. Solvent extracts of the oyster, its dietary phytoplankton and the feces were examined colorimetrically to compare their absorption spectra. The pigments extracted from the oyster were found consisting of chlorophyll and carotenoids. It was confirmed that the green pigments in the oyster are of plankton origin, and their total amount depends upon the amount of chlorophyll a contained in the suspension in environmental water. The green pigments deposited in the oyster body decreased when the oyster were kept in filtered water for a few days. The developed gonad covers the digestive diverticula portion to make the green color pigmentation rather invisible, which seems another reason why the green color differs between individuals as well as between the season.

In Roman wall paintings, blue and green colours are less commonly encountered than red and yellow and were more expensive. Despite this, Pliny and Vitruvius describe the more common compounds used for these pigments, translated today as azurite, lazurite, chrysocolla, indigo and Egyptian blue for blues and verdigris, malachite, celadonite, glauconite and chlorite for greens. A confusion in their nomenclature is often found in the most common blue pigment that is the first manufactured compound, Egyptian blue. For greens, celadonite and glauconite were usual and called generically ‘green earths’, but they prove to be difficult to characterize analytically. In this paper, we evaluate the Raman spectroscopic identification of the characteristic Roman blue and green pigments as used in wall paintings using two different laser wavelengths (green and near infrared) and clarify their nomenclature.

Propolis has health beneficial properties attributed to its phenol composition. Although, it has low water solubility, strong taste, and aroma, limiting its application in the food industry. This study explores the stabilization of phenolic compounds from propolis extract (PE) during the production of potato and cassava starch nanoparticles (NPs) by antisolvent precipitation. Phenolic content and antioxidant capacity (ABTS and DPPH) of acidified PE obtained with different ethanol concentrations are determined. Starch NPs based on cassava and potato starch are characterized in terms of physicochemical properties, including loading efficiency, particle size distribution and surface charge, moisture content, water activity, chemical bonds, crystalline structure, thermal stability, color, and solubility in water. Fourier‐transform infrared spectra and X‐ray diffractograms reveal that the phenolic compounds of PE are stabilized with the starch NPs, in this way, at least 54.91% of phenolic compounds from PE are stabilized by the starch NPs. Starch NPs stabilizing the phenolic compounds display brown color and high solubility in hot water (90 °C). This research reports for the first‐time information regarding the stabilization of phenolic compounds from PE using starch NPs. These starch NPs have a great potential to be used in food formulations or to manufacture active food packaging.

As novel green pigment, various sodium iron phosphates, Na4Fe7(PO4)6, NaFe4(PO4)3, and Fe3(PO4)2, imitated with Xenophillite and Vivianite, were synthesized using a hydrothermal process. The obtained powders were estimated with X-ray diffraction (XRD), Infrared (IR) spectra, ultraviolet–visible (UV–vis) reflectance spectra, and L*a*b* color space. The hydrothermal temperature and time, volume of water, phosphorus resource were studied in this process. All samples prepared in this work were dark green powders. The weak peaks of Na4Fe7(PO4)6 and Fe3(PO4)2 were observed in XRD patterns of all samples. Hydrothermal treatment of a long duration produced high greenish powders. The large volume of water used improved the greenish and bluish colors of the phosphate powders.

ABSTRACTMembers of the genus Rickettsiella are bacterial pathogens of insects and other arthropods. Recently, a novel facultative endosymbiont, “Candidatus Rickettsiella viridis,” was described in the pea aphid Acyrthosiphon pisum, whose infection causes a striking host phenotype: red and green genetic color morphs exist in aphid populations, and upon infection with the symbiont, red aphids become green due to increased production of green polycyclic quinone pigments. Here we determined the complete genome sequence of the symbiont. The 1.6-Mb circular genome, harboring some 1,400 protein-coding genes, was similar to the genome of entomopathogenic Rickettsiella grylli (1.6 Mb) but was smaller than the genomes of phylogenetically allied human pathogens Coxiella burnetii (2.0 Mb) and Legionella pneumophila (3.4 Mb). The symbiont’s metabolic pathways exhibited little complementarity to those of the coexisting primary symbiont Buchnera aphidicola, reflecting the facultative nature of the symbiont. The symbiont genome harbored neither polyketide synthase genes nor the evolutionarily allied fatty acid synthase genes that are suspected to catalyze the polycyclic quinone synthesis, indicating that the green pigments are produced not by the symbiont but by the host aphid. The symbiont genome retained many type IV secretion system genes and presumable effector protein genes, whose homologues in L. pneumophila were reported to modulate a variety of the host's cellular processes for facilitating infection and virulence. These results suggest the possibility that the symbiont is involved in the green pigment production by affecting the host’s metabolism using the secretion machineries for delivering the effector molecules into the host cells.

Naphthol Green – a forgotten artists’ pigment of the early 20th century. History, chemistry and analytical identification

Common dolphin fillets form green pigment near abdominal cavity and dorsal fin during freezing storage. The cause of discoloration was studied chemically and microbio-logically. The spectral properties of aqueous extracts of natural green meat obtained by soaking normal meat in saturated hydrogen sulfide solution resembled those of sword-fish and tuna varieties. Inoculation of Pseudomonas putrefaciens to fresh dolphin meat did not produce green pigment during storage. The difference in hydrogen sulfide-producing bacteria counts was not significant between normal and green meat. Irradiation accelerated the pink pigmentation which turned green upon soaking in saturated hydrogen sulfide solution.

The solid-state synthesis and stabilization of Co doped (Mg1−xCoxTi2O5), Zn doped (Mg1−xZnxTi2O5) and Co- and Zn-codoped karrooite solid solutions (Mg0.8−xZn0.2CoxTi2O5 and (Mg0.5Zn0.5)1−xCoxTi2O5) were investigated. In addition, the optical spectra, color properties and technological performance of (Co,Zn)-karrooite compositions as new green ceramic pigments were also analyzed. XRD characterization revealed for the first time the high solid solubility of Zn2+ in MgTi2O5 karrooite at 1200 ºC (between 60 and 80 mol% per Mg or karrooite formula unit). In contrast, the reactivity and stabilization of karrooite phase decreased in the case of Co2+ doping. Interestingly, codoping with Zn2+ ions at high molar ratios (Zn:Mg ratio equal to 1:1) enhanced the reactivity and enabled the stabilization of (Co,Zn)-MgTi2O5 karrooite solid solutions, even with high Co2+ loadings (20 mol% per karrooite formula unit). The (Co,Zn)-MgTi2O5 pigments exhibited yellowish-green colors associated to Co2+ ions allocated in octahedral M1 and M2 sites of karrooite lattice, and becoming more intense and less yellow the higher the Co content. However, Zn2+ codoping produced less saturated green colors with similar green but lower yellowish hues. The obtained pigments were not stable enough within the tested ceramic glazes, giving rise to turquoise colorations due to cobalt leaching and incorporation into tetrahedral sites of the glassy phase. The stability of Co-karrooite green pigments was higher in a Ca- and Zn-enriched ceramic glaze (B) fired at a higher temperature (1050 °C).

The late eighteenth century Eidsvoll manor house in Norway was modernised in the first two decades of the nineteenth century. The house and its interiors were colour examined during an architectural paint research. Two colour schemes from the early nineteenth century were found; a light greyish lead white and a green copper-based oil paint. The green colour scheme had discoloured severely. In this paper we discuss the results of synchrotron based infrared spectroscopy experiments on the green paint, which consisted of a verdigris pigment used in oil with lead white and chalk. The analytical results are compared with contemporary recipes found in painters’ handbooks around 1800 and seems to be darker than any recipe provided.