Chemometric evaluation of enzymatic hydrolysis in the production of fish protein hydrolysates with acetylcholinesterase inhibitory activity.

Fish protein hydrolysates (FPH) obtained from industrial processing residues are sources of bioactive peptides. The enzymatic hydrolysis process is essential in obtaining specific bioactivities such as inhibition of the enzyme acetylcholinesterase (AChE). In this study the effect of different hydrolysis conditions on the properties of FPH to inhibit the enzyme acetylcholinesterase. A chemometric evaluation, based on a central composite rotatable design and principal component analysis, was applied to select hydrolysis conditions with best yield, degree of hydrolysis and acetylcholinesterase inhibition. Experimental design results for AChE inhibition were between 10.51 and 40.45% (20, 30 and 50 mg.mL-1 of FPH), and three hydrolysis conditions were selected based on PCA evaluation. The amino acids profile, FTIR and AChE inhibition kinetics were evaluated. Results showed a mixed type of inhibition behavior and, the docking molecular analyzes suggest that the inhibition AChE occurred due to the basic amino acids, mainly by arginine.

Effect of land-use types on the ecomorphological structure of fish assemblage in distinct mesohabitats of neotropical streams / Efeito dos tipos de uso do solo na estrutura ecomorfológica da assembleia de peixes em distintos mesohábitats de riachos neotropicais

Abstract The use and occupation of land by human population substantially influence environmental variables and fish assemblage in streams. However, there is little knowledge on how these changes affect the ecomorphological structure of fish assemblage in mesohabitats. Therefore, we aim to assess whether the land-use types affect the ecomorphological structure of fish assemblage in distinct mesohabitats. Environmental and ichthyofaunistic data were collected in three mesohabitats (rifles, runs, and pools) of five rural and five urban streams. Twenty-one ecomorphological indices were obtained from the mean of linear morphological measurements and areas of the fishes. Subsequently, the Euclidean distance was calculated, based on the ecomorphological indices, between each pair of species, to measure the ecomorphological distances for the mesohabitats of the rural and urban streams. The results show that the urban environment is more harmful to streams than the rural one, due to changes in the environmental variables and decrease in species richness. The main environmental changes found in urban streams were the decrease in canopy cover by riparian vegetation and dissolved oxygen, and the increase in electrical conductivity and bed silting. Also, there was a significant decrease in the morphological similarity between fish species in the mesohabitats of urban streams compared to rural ones. Therefore, we can conclude that the urban environment leads to the loss of morphologically similar fish species in the mesohabitats, with only a few functionally distinct species remaining.

Resumo O uso e ocupação do solo pela população humana influencia substancialmente as variáveis ambientais e a assembleia de peixes em riachos. No entanto, há pouco conhecimento de como estas alterações afeta a estrutura ecomorfológica da assembleia de peixes em mesohábitats. Portanto, objetiva-se avaliar se o tipo do uso do solo afeta a estrutura ecomorfológica da assembleia de peixes nos distintos mesohábitats. Dados ambientais e ictiofaunísticos foram coletados em três mesohabitats (corredeiras, rápidos e remansos) de cinco riachos rurais e cinco urbanos. Vinte e um índices ecomorfológicos foram obtidos a partir das médias das medidas morfológicas lineares e áreas dos peixes. Posteriormente, a distância Euclidiana foi calculada, baseada nos índices ecomorfológicos, entre cada par de espécies, afim de mensurar as distâncias ecomorfológicas para os mesohábitats dos riachos rurais e urbanos. Os resultados mostram que o ambiente urbano é mais danoso aos riachos do que o rural, devido a diminuição da riqueza de espécies e as alterações nas variáveis ambientais. As principais mudanças ambientais encontradas em riachos urbanos foram a diminuição da cobertura do dossel pela vegetação ripária e do oxigênio dissolvido e o aumento da condutividade elétrica e do assoreamento do leito. Além disso, houve uma diminuição significativa da similaridade morfológica entre as espécies de peixes nos mesohábitats de riachos urbanos em comparação com os rurais. Portanto, podemos concluir que o ambiente urbano leva à perda de espécies de peixes morfologicamente similares nos mesohábitats, restando apenas algumas espécies funcionalmente distintas.

Limonoid detection and profile in callus culture of sweet orange

Plant tissue culture has emerged as an important tool to produce bioactive compounds from various plant species, including the sustainable production of limonoids that are receiving considerable attention due to the benefits associated with human health such as anticancer activities. The purpose of the present study was to evaluate the capacity of limonoids aglycone production from callus culture from sweet orange cv. Pera (Citrus sinensis) seeds and identify the compounds produced in this cell line. Callus induction occurred in Murashige and Skoog medium supplemented with 2,4-dichlorophenoxyacetic (2,4-D), malt extract, agar and coconut water. For the analysis and identification of the limonoids, CG-MS-EI ion-positive mode and UPLC-QTOF-ESI were used operating in positive and negative mode. An intense peak corresponding to limonin appeared in the callus extracts at a retention time of 58.1 min. in CG-MS-EI and four major limonoids aglycone by positive ion mode UPLC-QTOF-ESI: limonin, nomilin, deacetylnomilin, and nomilinic acid. The culture medium was efficient at the bioproduction of limonoids aglycone in callus cultures of C. sinensis seeds. Therefore, data obtained from UPLC-QTOF-ESI proved its importance at identifying new compounds that benefit human health, and may assist future work in the identification of known or new limonoids in Citrus species and related genera.