scholarly journals Degradação de metil e propil parabenos usando sistemas O3/H+, O3/OH- e O3/Mn2+

Revista DAE ◽  
2021 ◽  
Vol 70 (234) ◽  
pp. 202-213
Author(s):  
Eliel Albuquerque Aguiar ◽  
Jéssica Rocha de Lima ◽  
Aluísio Marques da Fonseca ◽  
Bruno César Barroso Salgado ◽  
Rinaldo dos Santos Araújo
Keyword(s):  

Este estudo teve como objetivo avaliar a degradação do metil e propil parabenos pelo processo de ozonização em meios ácido (pH = 5), alcalino (pH = 10) e catalítico (Mn2+, pH = 3). Os estudos cinéticos foram conduzidos a temperatura ambiente (27°C) para uma dosagem constante de 79 g/m3 de O3 na concentração inicial de 50 mg/L. Os resultados mostraram uma degradação de 100% para ambos os parabenos após 3 min de reação para o sistema alcalino. A cinética de degradação dos parabenos foi descrita pelo modelo cinético de primeira ordem com R2 entre 0,990 e 0,999. A ozonização alcalina (O3/OH-) apresentou constantes de velocidade de duas a três vezes superiores às observadas em meio ácido e catalítico. A não toxicidade das amostras tratadas frente à Artemia salina foi confirmada apenas para os processos de ozonização ácida e catalítica. Em geral, os resultados de degradação dos parabenos para os sistemas de ozonização aplicados foram promissores, embora os sistemas ácido e catalítico sejam os ambientalmente mais aceitáveis. Palavras-chave: Ozônio. Parabenos. Degradação. Cinética. Toxicidade.

Author(s):  
M. Boublik ◽  
R.M. Wydro ◽  
W. Hellmann ◽  
F. Jenkins

Ribosomes are ribonucleoprotein particles necessary for processing the genetic information of mRNA into proteins. Analogy in composition and function of ribosomes from diverse species, established by biochemical and biological assays, implies their structural similarity. Direct evidence obtained by electron microscopy seems to be of increasing relevance in understanding the structure of ribosomes and the mechanism of their role in protein synthesis.The extent of the structural homology between prokaryotic and eukaryotic ribosomes has been studied on ribosomes of Escherichia coli (E.c.) and Artemia salina (A.s.). Despite the established differences in size and in the amount and proportion of ribosomal proteins and RNAs both types of ribosomes show an overall similarity. The monosomes (stained with 0.5% aqueous uranyl acetate and deposited on a fine carbon support) appear in the electron micrographs as round particles with a diameter of approximately 225Å for the 70S E.c. (Fig. 1) and 260Å for the 80S A.s. monosome (Fig. 2).


2014 ◽  
Vol 25 (1-2) ◽  
pp. 69-82 ◽  
Author(s):  
L. P. Kharchenko ◽  
I. A. Lykova

Seasonal migration for birds – distant migrants are the most energy intensive. Fat reserves accumulated in the bird’s body before migration and during migratory stopovers determine success of the long-distance flight. Lipids play a vital role both as a source of energy and as structural components of cell membranes. For most migrants to the speed and quality processes fat accumulation affects the feed ration in the field of migration stops. Fodder saturation with essential polyunsaturated fatty acids (PUFAs) is of great importance. Being paramount for physiological processes, these acids cannot be synthesized in the bird’s body. The proposed article is dedicated to the study of waders’ trophic relationships with their prey items, and the use of PUFAs as biochemical markers. This approach is based on the specificity of the fatty acids contained in the lipids of invertebrate to be used as food bird species studied. Significant amount NPZHK waders obtained from forage that can be considered PUFAs as biochemical markers to determine the range and diversity of food producing birds PUFAs ways, and also to study the food chain in ecosystems. A fatty acid spectrum (FAS) of the lipids common for nine littoral invertebrate species (Gammarus aequicauda, Idotea balthica, Artemia salina, Nerеis sp., Nerеis zonata, Theodoxces astrachanicus, Hydrobia acuta, Chironomus salinarius, Chironomus plumosus), which constitute the main component of waders’ diet at the migratory stopover sites in the Azov and Black Sea region, has been studied. Found that the largest amount of total lipids contained in Nereis zonata (4,6 %) and Artemia salina (4,4 %), the lowest amount of total lipids was observed in Chironomus (1,5–1,8 %), which implies that polychaete worms and Artemia salina, as a source of fat, are the most productive for waders. Our research has found that mollusks, polychaete worms, and Artemia salina are the most effective waders’ fodder in the PUFAs content. Mollusks contain the largest amount of PUFAs, their spectrum is ω3 and ω6 PUFAs, especially arаchidonic acid C20:4. Polychate worms are also characterized by a high PUFAs level; they serve for birds as a source of linolenic and linoleic acid groups. Artemia salina contains a large amount of eicosapentaenoic С20:5ω3 and docosahexaenoic С22:6ω3 acids, which getting to an organism of birds, participating in the formation of cell membranes, act as thermal stabilizer lipid bilayers, enhance stamina during long-distance flight. A high abundance of Artemia salina in the feeding areas permit tundra waders to use them as a prey item, which can fulfill the bird’s body with a required amount of fatty acids in a short time. We have established an influence of some environmental factors, as water temperature and salinity, on the lipids FAS of littoral invertebrates. Spectrum analysis of polyene fatty acids in the lipids closely related species of invertebrates living in different salinity water showed that the content of PUFAs in the lipid depend on their food spectrum, and the environmental conditions. Therefore, anthropogenic pressure and changes of water hydrological regime may affect PUFAs content in the lipids of littoral invertebrates. In its turn, this factor may change alimentary behavior and migratory strategy of the birds, which use migratory stopover sites in the region in question. Shallow waters of the Azov-Black Sea region are characterized by different climatic characteristics and a large reserve of phytoplankton. This explains the mass character species studied of invertebrates to feeding areas and their use as basic prey items, many species of waders.


2020 ◽  
Vol 16 (9) ◽  
pp. 1309-1317
Author(s):  
Anusha Rajagopalan ◽  
Bindhu O. Sukumaran

Background: Aqueous leaf extract of Wrightia tinctoria has been in use for artisanal cheese preparation in diverse parts of India. Scientific validation behind the milk clotting potential of W. tinctoria stem proteases purified through three-phase partitioning (TPP) has been attempted. However, its contribution to cheese quality standards has not been tried yet. Objective: To evaluate the suitability of three-phase partitioned W. tinctoria (WT) stem proteases in fresh cheese making. Methods: Fresh cheese was prepared using W. tinctoria TPP proteases and its characteristics were compared with that of commercial plant milk coagulant, Enzeco® (CEz) and rennin (CRn). Yield, organoleptic and textural properties, total fat, protein and moisture content of all cheese were determined according to FSSAI standards. Toxicity of the TPP proteases was assessed on the shrimp model (Artemia salina egg and Litopenaeus vannamei post-larval shrimps). Results: TPP proteases were found to be non-toxic and safe for human consumption with no change in egg hatchability and survival of the shrimps in comparison to that of control. Cheese analysis results indicated perceptible resemblance in nutritional characteristics of WT cheese with control cheese. Yield, textural properties and organoleptic acceptance of WT cheese resembled more closely with that of CEz cheese. Conclusion: Observation from the study paves the way for the acceptance of W. tinctoria proteases as a suitable vegetable rennet for fresh cheese making.


Marine Drugs ◽  
2020 ◽  
Vol 19 (1) ◽  
pp. 5
Author(s):  
Daniela Pereira ◽  
Catarina Gonçalves ◽  
Beatriz T. Martins ◽  
Andreia Palmeira ◽  
Vitor Vasconcelos ◽  
...  

Over the last decades, antifouling coatings containing biocidal compounds as active ingredients were used to prevent biofouling, and eco-friendly alternatives are needed. Previous research from our group showed that polymethoxylated chalcones and glycosylated flavones obtained by synthesis displayed antifouling activity with low toxicity. In this work, ten new polymethoxylated flavones and chalcones were synthesized for the first time, including eight with a triazole moiety. Eight known flavones and chalcones were also synthesized and tested in order to construct a quantitative structure-activity relationship (QSAR) model for these compounds. Three different antifouling profiles were found: three compounds (1b, 11a and 11b) exhibited anti-settlement activity against a macrofouling species (Mytilus galloprovincialis), two compounds (6a and 6b) exhibited inhibitory activity against the biofilm-forming marine bacteria Roseobacter litoralis and one compound (7b) exhibited activity against both mussel larvae and microalgae Navicula sp. Hydrogen bonding acceptor ability of the molecule was the most significant descriptor contributing positively to the mussel larvae anti-settlement activity and, in fact, the triazolyl glycosylated chalcone 7b was the most potent compound against this species. The most promising compounds were not toxic to Artemia salina, highlighting the importance of pursuing the development of new synthetic antifouling agents as an ecofriendly and sustainable alternative for the marine industry.


2010 ◽  
Vol 11 (2) ◽  
Author(s):  
Josiane F. G. Dias ◽  
Milena Kalegari ◽  
Marilis D. Miguel ◽  
Sandra M. W. Zanin ◽  
Ana Luisa L. Lordello ◽  
...  
Keyword(s):  

O extrato, frações e substâncias isoladas das cascas de G. vellosii foram submetidos ao teste de bioatividade sobre A. salina. Os dados foram analisados pelo método Probitos e determinados os valores de DL50 e 95% de intervalos de confiança. As amostras foram consideradas ativas quando DL50 < 1000 µg.mL-1. Todas as amostras testadas demonstraram bioatividade contra A. salina, destacando-se F4 e F9, as quais apresentaram valores de DL50 de 7,60 e 29,48 µg.mL-1, respectivamente. Os resultados demonstram o potencial biotecnológico da espécie, pois segundo literatura este bioensaio pode ser utilizado como avaliação prévia de possível atividade antitumoral


1974 ◽  
Vol 52 (3) ◽  
pp. 231-240 ◽  
Author(s):  
A. H. Warner ◽  
P. C. Beers ◽  
F. L. Huang

An enzyme that catalyzes the synthesis of P1P4-diguanosine 5′-tetraphosphate (Gp4G) has been isolated and purified from yolk platelets of encysted embryos of the brine shrimp, Artemia salina. The enzyme GTP:GTP guanylyltransferase (Gp4G synthetase) utilizes GTP as substrate, has a pH optimum of 5.9–6.0, a temperature optimum of 40–42 °C, and requires Mg2+ and dithiothreitol for optimal activity. The synthesis of Gp4G is inhibited markedly by pyrophosphate, whereas orthophosphate has no effect on the reaction. In the presence of GDP the enzyme also catalyzes the synthesis of P1,P3-diguanosine 5′-triphosphate (Gp3G), but the rate of synthesis is low compared with Gp4G synthesis and dependent upon other small molecular weight components of yolk platelets.


1973 ◽  
Vol 58 (3) ◽  
pp. 643-649 ◽  
Author(s):  
H. Schmitt ◽  
H. Grossfeld ◽  
U. Z. Littauer

Mitochondria isolated from cysts of Artemia salina (brine shrimp) were found to be devoid of cristae and to possess a low respiratory capability. Hydration of the cysts induces marked biochemical and morphological changes in the mitochondria. Their biogenesis proceeds in two stages. The first stage is completed within 1 h and is characterized by a rapid increase in the respiratory capability of the mitochondria, their cytochrome oxidase, cytochrome b, cytochrome c and perhaps some morphological changes. In the second stage there is an increase in the protein-synthesizing capacity of the mitochondria as well as striking changes in mitochondrial morphology leading to the formation of cristae.


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