Análise do efeito biológico de nanopartículas de ouro reduzidas com extrato de Punica granatum L. sobre Escherichia coli ATCC 25922

The rise in antimicrobial resistance has become a critical public health concern, requiring new approaches to face pathogens. Gold nanoparticles (AuNPs) are deemed promising in the fight against pathogenic biofilms due to their unique physicochemical characteristics, which can be tailored for specific purposes. In the present study, we employed the green synthesis of AuNPs, using pomegranate peel extract (Punica granatum L.) as a reducing agent, due to its antioxidant properties and the inherent non-toxicity of the method. For the synthesis of the AuNPs, two techniques were employed: sodium citrate chemical reduction and the green synthesis method using pomegranate extract. The nanoparticles were characterized through spectroscopic and imaging techniques, such as UV-Vis, Raman spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Dynamic Light Scattering (DLS), and Transmission Electron Microscopy (TEM). The phenolic compounds present in the extract and in the AuNPs were identified by HighPerformance Liquid Chromatography coupled to mass spectrometry (HPLC-MS). The success of the AuNP synthesis was initially confirmed by the reddish hue of the resulting colloid and the absorbance pattern in the UV-Vis spectra. Spectroscopic analyses showed the presence of various organic compounds in the pomegranate peel, such as amino acids, phenols, ellagic tannins, and gallic and ellagic acid esters, which participate in the stabilization of the AuNPs. The gold concentration in the nanoparticles was 42.70 μg/mL, while the concentration of pomegranate extract present in the nanoparticles was 380 μg/mL. The AuNPs exhibited a hydrodynamic size in the range of 68.80 nm and a zeta potential of -16.4 mV, indicating stability in aqueous solution. The EC50 value obtained through the DPPH assay proved that the pomegranate extract has high antioxidant activity, greater than that of the Trolox standard. The evaluation of antimicrobial activity was carried out on the Escherichia coli ATCC 25922 strain. The highest concentration of gold nanoparticles with pomegranate extract (170.8 μg/mL) exhibited antimicrobial effect, which, although minimal, caused deformations in the bacterial membrane. In conclusion, the study describes an eco-friendly synthesis of gold nanoparticles using pomegranate extract, which exhibited high antioxidant potential. Although the AuNPs showed limited antimicrobial properties, they emerge as promising candidates for biomedical and nanotechnological applications, requiring additional studies to enhance their potential as antibacterial agents.O aumento da resistência antimicrobiana tornou-se uma preocupação de saúde pública crítica, necessitando de novas abordagens para o combate a patógenos. As nanopartículas de ouro (AuNPs) são apontadas como promissoras na luta contra biofilmes patogênicos devido às suas características físico-químicas únicas, que podem ser ajustadas para propósitos específicos. No presente estudo, empregamos a síntese verde de AuNPs, utilizando o extrato da casca da romã (Punica granatum L.) como agente redutor, devido às suas propriedades antioxidantes e à não-toxicidade inerente ao método. Para a síntese das AuNPs, foram empregadas duas técnicas: redução química por citrato de sódio e o método de síntese verde utilizando o extrato de romã. As nanopartículas foram caracterizadas através de técnicas espectroscópicas e de imagem, como UV-vis, espectrometria Raman, espectroscopia no infravermelho com transformada de Fourier (FTIR), Espectrometria de Massas com Plasma Indutivamente Acoplado (ICP-MS), Espalhamento Dinâmico de Luz (DLS) e Microscopia Eletrônica de Transmissão (MET). Os compostos fenólicos presentes no extrato e nas AuNPs foram identificados por Cromatografia Líquida de Alta Eficiência acoplada à espectrometria de massas (CLAE-EM). O sucesso da síntese das AuNPs foi inicialmente confirmado pela coloração avermelhada do coloide resultante e pelo padrão de absorbância nos espectros UV-Vis. As análises espectroscópicas mostraram a presença de diversos compostos orgânicos na casca da romã, como aminoácidos, fenóis, taninos elágicos e ésteres de ácido gálico e elágico, que participam na estabilização das AuNPs. A concentração de ouro nas nanopartículas foi de 42,70 μg/mL, enquanto a concentração de extrato de romã presente nas nanopartículas foi de 380 μg/mL. As AuNPs exibiram tamanho hidrodinâmico na faixa de 68,80 nm e um potencial zeta de -16,4 mV, indicando estabilidade em solução aquosa. O valor do EC50 obtido através do ensaio de DPPH provou que o extrato de romã possui alta atividade antioxidante, maior do que a do padrão Trolox. A avaliação da atividade antimicrobiana foi realizada na cepa de Escherichia coli ATCC 25922. A maior concentração de nanopartículas de ouro com extrato de romã (170,8 μg/mL) exibiu efeito antimicrobiano, que, embora ínfimo, causou deformações na membrana bacteriana. Em conclusão, o estudo descreve uma síntese eco-friendly de nanopartículas de ouro utilizando extrato de romã, que exibiram um elevado potencial antioxidante. Embora as AuNPs tenham mostrado propriedades antimicrobianas limitadas, elas surgem como candidatas promissoras para aplicações biomédicas e nanotecnológicas, exigindo estudos adicionais para aprimorar seu potencial como agentes antibacterianos

Indirect somatic embryogenesis in Coffea with different ploidy levels: a revisiting and updating study

Indirect somatic embryogenesis (ISE) is required for plant propagation and a prerequisite for applications that may provide new germplasms. Genetic, epigenetic and physiological features of the explant donor are barriers for ISE establishment, hindering its wide use. Despite the identification and/or expression analysis of genes during ISE, no approach to establish the karyotype aspects has been performed so far. So, this study aims to establish the ISE and compare the in vitro responses between diploid (Coffea canephora and Coffea eugenioides), allotriploid (“Híbrido de Timor”—HT) and true allotetraploid (Coffea arabica) Coffea in a taxonomic and evolutive scenario. Under the same in vitro conditions, the four Coffea differed from each other during ISE. Leaf explants of the true allopolyploids yielded the highest mean number of friable calli (FC) in relative short time and visually exhibiting more pronounced length. FC of the allotetraploid C. arabica presented the highest mean number of mature cotyledonary somatic embryos (MCSE), which were also recovered faster in this species. However, MCSE mean number in HT was the same or lower than diploid Coffea. Besides, intraspecific variation related to the ISE responses was observed in each Coffea, mainly the mean number of FC obtained from ex vitro and in vitro C. arabica and C. eugenioides explants. So, epigenetic and physiologic features may also have influenced the ISE responses. The findings provide the basis for performing other approaches considering the ploidy level, epigenetic and physiological backgrounds. Besides, the data also contributed for understanding about the consequences of polyploidy

Indirect somatic embryogenesis in Coffea with different ploidy levels: a revisiting and updating study

Indirect somatic embryogenesis (ISE) is required for plant propagation and a prerequisite for applications that may provide new germplasms. Genetic, epigenetic and physiological features of the explant donor are barriers for ISE establishment, hindering its wide use. Despite the identification and/or expression analysis of genes during ISE, no approach to establish the karyotype aspects has been performed so far. So, this study aims to establish the ISE and compare the in vitro responses between diploid (Coffea canephora and Coffea eugenioides), allotriploid (“Híbrido de Timor”—HT) and true allotetraploid (Coffea arabica) Coffea in a taxonomic and evolutive scenario. Under the same in vitro conditions, the four Coffea differed from each other during ISE. Leaf explants of the true allopolyploids yielded the highest mean number of friable calli (FC) in relative short time and visually exhibiting more pronounced length. FC of the allotetraploid C. arabica presented the highest mean number of mature cotyledonary somatic embryos (MCSE), which were also recovered faster in this species. However, MCSE mean number in HT was the same or lower than diploid Coffea. Besides, intraspecific variation related to the ISE responses was observed in each Coffea, mainly the mean number of FC obtained from ex vitro and in vitro C. arabica and C. eugenioides explants. So, epigenetic and physiologic features may also have influenced the ISE responses. The findings provide the basis for performing other approaches considering the ploidy level, epigenetic and physiological backgrounds. Besides, the data also contributed for understanding about the consequences of polyploidy

NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics

Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data