Academic literature on the topic 'Phycobilins'

Abstract:The pigment content in microalgae is a specific feature of each species. Colors from natural sources are gaining more importance mainly due to health and environmental issues. Algae contain a wide range of pigments. Three major classes of pigments are chlorophylls, carotenoids (carotenes and xanthophylls) and phycobilins (Phycocyanin and phycoerythrin). Phycocyanin and phycoerythrin belong to the major class of phycobilins photosynthetic pigment while fucoxanthin and peridinin belong to carotenoid group of photosynthetic pigment. Macro- and microalgae (including cyanobacteria) have been recognized to provide a wide diversity of metabolites including pigments for energy capture and photo-protection. One of the main objectives is to identify and select potential micro- and macroalgae species that can be used a raw material for the color industry.

Abstract:The pigment content in microalgae is a specific feature of each species. Colors from natural sources are gaining more importance mainly due to health and environmental issues. Algae contain a wide range of pigments. Three major classes of pigments are chlorophylls, carotenoids (carotenes and xanthophylls) and phycobilins (Phycocyanin and phycoerythrin). Phycocyanin and phycoerythrin belong to the major class of phycobilins photosynthetic pigment while fucoxanthin and peridinin belong to carotenoid group of photosynthetic pigment. Macro- and microalgae (including cyanobacteria) have been recognized to provide a wide diversity of metabolites including pigments for energy capture and photo-protection. One of the main objectives is to identify and select potential micro- and macroalgae species that can be used a raw material for the color industry.

Berberine, as an allelochemical extracted from golden thread (Coptis chinensis), inhibits the growth of Microcystis aeruginosa significantly. To assess berberine-induced damage on the algal photosynthetic apparatus, the effects of berberine on the algal photosynthetic pigments compositions and ultrastructure were investigated. The results showed that the relative chlorophyll a content of M. aeruginosa decreased with the increasing concentrations of berberine and the prolongation of exposure time. The relative contents of phycocyanin, allophycocyanin and phycoerythrin of M. aeruginosa transitioned from a decrease to an increase in the early phase of the experiment, and then decreased sharply to the end at low concentrations. However, when berberine concentration raised to 20.0 mg·L-1, all the relative phycobilins contents of M. aeruginosa had been decreasing with the prolongation of exposure time. Of the three phycobilins of M. aeruginosa, phycocyanin was affected most severely by berberine. TEM photographs showed that the ultrastructures of the multiple-layered cell wall, cell membrane and thylakoid lamella of M. aeruginosa were destroyed severely under the stress of berberine with the occurrence of cyanophycin granules. It was concluded that decreases in the photosynthetic pigments and destruction of the algal cells ultrastructures might be involved in berberine-caused antialgal mechanism.

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FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais
A Strelitziaceae é uma família de monocotiledôneas pertencente a ordem Zingiberales que possui três gêneros: Strelitzia com cinco espécies na África meridional, Ravenala com uma única espécie em Madagascar e Phenakospermum com uma única espécie no norte da América do sul. A Ravenala madagascariensis produz um arilo fibroso de textura graxa e cor azul, que ao contrário da maioria dos tecidos vegetais não perdem a cor após morte celular. O que desperta o interesse do estudo dessa espécie do ponto de vista químico é (I) a raridade de pigmentos azuis nas plantas e (II) a maior estabilidade do pigmento comparado com as classes mais conhecidas como: os carotenóides, flavonóides, betalainas e clorofilas, o que torna este pigmento um atrativo candidato para o uso em cosméticos e na indústria alimentícia. Neste trabalho descreve-se as tentativas de isolamento, purificação, análise e caracterização das macromoléculas naturais presentes na fração apolar e polar dos arilos da R. madagascariensis. Na fração apolar, identificou-se a presença de triglicerídeos, que corresponde a aproximadamente 70% dos arilos, através da análise por RMN de 1H e espectroscopia no infravermelho. A identidade e proporção relativa dos ácidos graxos presentes foi determinado por GC-MS, cálculo do índice de Kováts e da comparação dos tempos de retenção com padrões sintetizados. Os quatro componentes principais, presente nesta fração, são os ácidos: palmítico (C16:0, 41%), esteárico (C18:0, 14%), oleico (C18:1 ω9cis, 34%) e linoleico (C18:2 ω6, 7%). A análise da fração polar dos arilos sugere a presença de um cromóforo da classe das ficobilinas, tetrapirróis lineares, devido às absorções em 680 e 620nm no UV-Vis dos extratos de HOAc e SDS, respectivamente, e do resultado positivo para o ensaio de Ehrlich. A avaliação dos espectros de infravermelho e Raman indicam a presença de uma proteína, devido as absorções características de amida I, II e III e a ausência de absorções na região de 500 a 200cm-1 no espectro Raman indica inexistência de um metal coordenado ao cromóforo. O perfil proteico obtido por eletroforese revela a presença de proteínas, com uma banda mais marcante na região de 48KDa, provavelmente envolvida no processo de formação da cor azul presente nos arilos da R. madagascariensis. As análises por RP-HPLC, nos diferentes comprimentos de onda, do extrato de SDS sugerem que o cromóforo é mantido por interações intermoleculares e não por ligações covalentes.
The Strelitziaceae is a family of monocotyledons belonging to the order Zingiberales which contains three genera: Strelitzia with five species in meridional África, Ravenala with a single specie in Madagascar and Phenakospermum with a single specie in the Northern regions of South America. Ravenala madagascariensis produces a fibrous aril with a waxy texture and blue coloration, which, contrary to the majority of plant tissues, does not lose its color after cell death. What is interesting from a chemical point of view is: I) the rarity of blue pigments in the plant kingdom and II) its stability is greater than other common classes of naturally occurring plant pigments such as carotenoids, betalains and chlorophyls which make it an attractive candidate as a pigment for use in food and cosmetics. The current work describes attempts to isolate, purify, analyze and characterize naturally occurring macromolecules present in the non-polar and polar fractions of the seed arils of R. madagascariensis. In the non-polar fraction, which comprises approximately 70% of the arils, the prescence of triacylglycerides was confirmed by 1H NMR and infrared spectroscopies. The identities and relative proportions of the fatty acids present were determined by GC-MS, calculation of their Kováts indices and by comparison to authenic reference standards after conversion to their methyl esters by transesterification. The four principal compounds encountered were: palmitic (C16:0, 41%), stearic (C18:0, 14%), oleic (C18:1 ω9cis, 34%) and linoleic (C18:2 ω6, 7%) acids. Analysis of the polar fraction of the arils suggests the presence of a chromophore related to the phycobilins, a class of tetrapyrrole pigments, due to absorptions at 680 and 620nm in the UV-Vis of the HOAc and SDS extracts respectively, and a positive result to the Ehrlich test. Examination of the infrared and Raman spectra indicate the presence of a protein, due to absorptions characteristic of amide I, II and III bands in the infrared, while the absence of absorptions in the region between 500 and 200cm-1 in the Raman spectra would indicate the absence of a metal coordinated to the chromophore.. The protein profile obtained by gel electrophoresis strongly suggests the presence of a protein with a mass of aproximately 48KDa, which possesses a chromophore responsible for the blue color observed in the arils of R. madagascariensis. Analysis by RP-HPLC at various wavelengths of the SDS extracts suggest that the chromophore is held in place by intermolecular interactions as opposed to covalent bonding.

O fitoplâncton é composto por uma gama de organismos fotossintetizantes de diversas origens evolutivas. São os principais produtores primários dos oceanos embora sua biodiversidade seja muito pouco estudada, principalmente as frações do nano e picoplâncton. A composição florística dessas duas frações do fitoplâncton marinho é praticamente desconhecida nas águas brasileiras, entretanto diversos trabalhos ecológicos e oceanográficos relatam sua importância, pois são os mais abundantes nas regiões marinhas. O presente estudo teve como objetivo isolar espécies de microalgas, com ênfase nos fitoflagelados, a partir de amostras coletadas de Cananéia, Ubatuba e Santos, a fim de aumentar o conhecimento acerca da composição taxonômica desses organismos e permitir estudos futuros, envolvendo análises moleculares, ultraestruturais e fisiológicas. Para isso, foram usadas várias técnicas tradicionais de isolamento, como cultura mista, micropipetagem e diluições sucessivas, plaqueamento em ágar e diluição seriada. Foram isolados 49 cepas das classes Cyanophyceae, Trebouxiophyceae, Cryptophyceae, Bacillariophyceae, Prasinophyceae, Nephroselmidophyceae, Chrysophyceae e outros não identificados. Análises pigmentares foram realizadas em especial para o grupo das Cryptophyceae para confirmar a identificação em nível genérico. Vários dos táxons isolados representam novos registros para o estado de São Paulo e para a costa do Brasil. Os resultados do presente estudo são uma boa partida para a inclusão filogenética dos organismos isolados na costa do Brasil no contexto mundial, auxiliando a desvendar a biodiversidade críptica de espécies até o momento desconhecidas para as regiões estudadas
Phytoplankton comprises a range of photosynthetic organisms with different evolutionary origins. They are the main primary producers in the oceans but its biodiversity is poorly studied, especially on the nano and picoplankton fractions. Although the floristic composition of these two fractions of the marine phytoplankton is virtually unknown in Brazilian waters, several studies have reported the oceanographic and ecological importance of these groups, which are the most abundant in marine environment. This study aimed to isolate microalgae species with emphasis on \"phytoflagellates\" from samples collected in Cananéia, Ubatuba and Santos in order to increase the knowledge about their taxonomic composition and allow future studies involving molecular, ultrastructural and physiological analysis. For this, several traditional single-cell isolation techniques were used such as enrichment culture, micropipette, agar plating and serial dilutions. There were isolated 49 strains of Cyanophyceae, Trebouxiophyceae, Cryptophyceae, Bacillariophyceae, Prasinophyceae, Nephroselmidophyceae, Chrysophyceae classes and others unidentified. Pigment analyzes were performed specially on Cryptophyceae group in order to confirm their identification at generic level. Several of the isolated taxa are new records for the state of São Paulo and the coast of Brazil. The findings of this study enable the phylogenetic inclusion of organisms isolated from the Brazilian coast in a world context, helping to unravel the cryptic biodiversity of organisms hitherto unknown for the studied regions

Presented work is focused on heme metabolism with the main interest in bile pigments. Recent data indicate that bilirubin is not only a waste product of the heme catabolic pathway, but also emphasize its important biological impacts, including possible antiproliferative effects. Until today metabolism of bilirubin has not been completely elucidated, which has prevented detailed evaluation of its potential anticancer action. The aim of this study was to clarify some aspects of heme catabolism with respect for antiproliferative properties of its products. Based on the fact that bilirubin potently affects carcinogenesis of the intestine, we initially investigated not properly known bilirubin metabolism by intestinal bacteria. We studied bilirubin neurotoxic effects in hyperbilirubinemic Gunn rats - its distribution in the brain tissue and its degradation during pathological conditions, such as severe newborn jaundice or Crigler-Najjar syndrome. Possible approaches to improve the treatment of severe unconjugated hyperbilirubinemias, combination of the phototherapy and human albumin administration were also investigated. The main reason of these studies was the fact that mechanisms of neurotoxic effects of bilirubin are predominantly identical with those, by which bilirubin inhibits cancer cells growth....

This chapter examines the primary photosynthetic pigments used in absorbing photosynthetically active radiation, which include chlorophylls, carotenoids, and phycobilins—with chlorophyll representing the dominant photosynthetic pigment. Although a greater amount of chlorophyll is found on land, 75% of the annual global turnover occurs in oceans, lakes, and rivers/estuaries. All of the light-harvesting pigments are bound to proteins making up distinct carotenoid and chlorophyll-protein complexes. The chapter considers the chemistry and application of these very important chemical biomarkers and discusses their limitations in aquatic systems. The matrix factorization program CHEMical TAXonomy (CHEMTAX) was introduced to calculate the relative abundance of major algal groups based on concentrations of diagnostic pigments and is also discussed.