Biological capacities of seven Chilean ferns.

Sticherus squamulosus, Hymenophyllum dentatum, Blechnum microphyllum, Polypodium Feuillei, Blechnum chilense, Lophosoria quadripinnata, and Lissopimpla excelsa are native fern species found in southern Chile and are often used in traditional medicine. However, their bioactive properties have not been confirmed. In this study, ethanolic extracts of ferns exhibited significant antibacterial capacity against human pathogens. H. dentatum and S. squamulosus were selected for further analysis owing to their antimicrobial and antioxidant capacities. The entire H. dentatum extract exhibited fungistatic and fungicidal capacity on Botrytis cinerea and Penicillium digitatum, with minimum inhibitory concentration values of 1.56 mg/mL and 6.25 mg/mL and minimum fungicidal concentration values of 6.25 mg/mL and 12.5 mg/mL, respectively. The S. squamulosus extract presented the highest rutin content (222.5 µg/g fern). In addition, the ethanolic extract of H. dentatum inhibited 91% of DPPH radicals. Therefore, both types of ferns can be used in the food industry.

Influence of chitin nanofibers and gallic acid on physical-chemical and biological performances of chitosan-based films.

In this work, chitosan films loaded with gallic acid and different content of chitin nanofibers were prepared and subjected to different characterization techniques. The results showed that the inclusion of gallic acid to chitosan films caused moderate decrease in water vapor permeability (by 29 %) and increased tensile strength of films (by 169 %) in comparison to the neat chitosan films. Furthermore, it was found that the addition of chitin nanofibers up to 30 % into chitosan/gallic acid films additionally improved tensile strength (by 474 %) and reduced plasticity of films (by 171 %), when compared to the chitosan/gallic acid films. Increased concentration of chitin nanofibers in films reduced the overall water vapor permeability of films by 51 %. In addition, gallic acid and chitin nanofibers had synergic effect on high chitosan film's antioxidant and antifungal activity toward Botrytis cinerea (both above 95 %). Finally, chitosan/gallic acid/chitin nanofibers films reduced decay incidence of strawberries, increased total soluble solid content, and promoted high production of some polyphenols during cold storage, in comparison to the control chitosan films and uncoated strawberry samples. Hence, these results suggest that chitosan/gallic acid/chitin nanofibers can present eco-sustainable approach for preservation of strawberries, giving them additional nutritional value.

Floral Pollen Bioactive Properties and Their Synergy in Honeybee Pollen.

Honeybee pollen (HBP) is a mixture of floral pollen collected by honeybees near the hive. It is characterized by a composition rich in phenolic compounds, carotenoids and vitamins that act as free radicals scavengers, conferring antioxidant and antibacterial capacity to the matrix. These bioactive properties are related to the botanical origin of the honeybee pollen. Honeybee pollen samples were collected from different geographical locations in central Chile, and their total carotenoid content, polyphenols profile by HPLC/MS/MS, DPPH radical scavenging capacity, and antimicrobial capacity against S. pyogenes, E. coli, S. aureus, and P. auriginosa strains were evaluated. Our results showed a good carotenoids content and polyphenols composition, while antioxidant capacity presented values between 0-95 % for the scavenging effect related to the botanical origin of the samples. Inhibition diameter for the different strains presented less variability among the samples, Furthermore, binary mixtures representing the two most abundant species in each HBP were prepared to assess the synergy effect of the floral pollen (FP) present in the samples. Data shows an antagonist effect was observed when assessing the carotenoid content, and a synergy effect often presents for antimicrobial and antioxidant capacity for bee pollen samples. The bioactive capacities of the honeybee pollen and their synergy effect could apply to develop new functional ingredients for the food industry.

Effect of Extraction Methods and In Vitro Bio-Accessibility of Microencapsulated Lemon Extract.

The extraction of bioactive compounds from fruits, such as lemon, has gained relevance because these compounds have beneficial properties for health, such as antioxidant and anticancer properties; however, the extraction method can significantly affect these properties. High hydrostatic pressure and ultrasound, as emerging extraction methods, constitute an alternative to conventional extraction, improving extractability and obtaining extracts rich in bioactive compounds. Therefore, lemon extracts (LEs) were obtained by conventional (orbital shaking), ultrasound-assisted, and high-hydrostatic-pressure extraction. Extracts were then microencapsulated with maltodextrin at 10% (M10), 20% (M20), and 30% (M30). The impact of microencapsulation on LEs physicochemical properties, phenolics (TPC), flavonoids (TFC) and relative bio-accessibility (RB) was evaluated. M30 promoted a higher microencapsulation efficiency for TPC and TFC, and a longer time required for microcapsules to dissolve in water, as moisture content, water activity and hygroscopicity decreased. The RBs of TPC and TFC were higher in microcapsules with M30, and lower when conventional extraction was used. The data suggest that microencapsulated LE is promising as it protects the bioactivity of phenolic compounds. In addition, this freeze-dried product can be utilized as a functional ingredient for food or supplement formulations.

Polyphenolic Composition and Antioxidant Activity (ORAC, EPR and Cellular) of Different Extracts of Argylia radiata Vitroplants and Natural Roots.

Plant biochemistry studies have increased in recent years due to their potential to improve human health. Argylia radiata is an extremophile plant with an interesting polyphenolic profile. However, its biomass is scarce and occasionally available. Argylia in vitro biomass was obtained from tissue culture and compared with in vivo roots regarding its polyphenolic and flavonoid content. Different solvents were used to prepare extracts from the in vitro tissue of callus and aerial plant organs and in vivo roots. UPLC-MS/MS was used to assess the chemical composition of each extract. ORAC-FL and scavenging of free radicals (DPPH and OH) methods were used to determine the antioxidant capacity of extracts. Furthermore, the biological activity of the extracts was established using the cellular antioxidant activity method. The vitroplants were a good source of polyphenols (25-68 mg GAE/100 g tissue FW), and methanol was the most efficient solvent. Eight polyphenolic compounds were identified, and their antioxidant properties were investigated by different chemical methods with EPR demonstrating its specific scavenging activity against free radicals. All extracts showed cellular dose-dependent antioxidant activity. The methanolic extract of vitroplants showed the highest cellular antioxidant activity (44.6% and 51%) at 1 and 10 µg/mL of extract, respectively. Vitroplants of A. radiata are proposed as a biotechnological product as a source of antioxidant compounds with multiple applications.

Biological activity of native Myrtaceae fruits from Chile as a potential functional food.

Myrtaceae fruits (Myrceugenia obtusa, Luma apiculata, and Luma chequen) were used as food and medicine by Chilean indigenous people. This study aimed to evaluate the bioactive properties of these berry-type fruits. The antioxidant capacity determined by the FRAP assay varied between 10.4 and 646.9 mmol Fe+2/g, while the antibacterial activity against Staphylococcus aureus and Salmonella typhi was 0 - 33 mm and 0 - 7.33 mm, respectively. All the extracts were rich in polyphenols and showed low cytotoxicity. Overall, M. obtusa presented dissimilar results compared to those of L. apiculata and L. chequen, encouraging the use of these native fruits as food, nutraceutical, or pharmacological ingredients.

Mayten Tree Seed Oil: Nutritional Value Evaluation According to Antioxidant Capacity and Bioactive Properties.

The Mayten tree (Maytenus boaria Mol.), a native plant of Chile that grows under environmentally limiting conditions, was historically harvested to extract an edible oil, and may represent an opportunity to expand current vegetable oil production. Seeds were collected from Mayten trees in north-central Chile, and seed oil was extracted by solvent extraction. The seed oil showed a reddish coloration, with quality parameters similar to those of other vegetable oils. The fatty acid composition revealed high levels of monounsaturated and polyunsaturated fatty acids. Oleic and linoleic acids, which are relevant to the human diet, were well represented in the extracted Mayten tree seed oil. The oil displayed an antioxidant capacity due to the high contents of antioxidant compounds (polyphenols and carotenoids) and may have potential health benefits for diseases associated with oxidative stress.

Bioactive compounds in Apis mellifera monofloral honeys.

Honey is a natural product with a sweet flavor. Honey is made by the honeybee (Apis mellifera L.) from the nectar of flowers or other plant secretions that are collected near the hive. These products are mixed with bee saliva and stored. Several studies have demonstrated that honey exhibits antioxidant, antimicrobial, nematicidal, antifungal, anticancer, and anti-inflammatory activities. These properties are influenced by the plants from which the secretions are harvested, from the naturally occurring compounds present in the nectar. Studies of the properties and applications of honey have distinguished honey from other natural products due to the presence of certain compounds and due its bioactive properties. The focus of this review is to discuss the identified and isolated compounds from monofloral honey produced by A. mellifera, with specific emphasis on antioxidant and antimicrobial properties of honey and its therapeutic health benefits.

Antibacterial potential assessment of Nalca (Gunnera tinctoria Mol.) ethanolic extracts.

Nalca is an edible rhubarb-type plant from the southern of Chile; with studies focussing on petiole chemical and biological properties. This work evaluated for the first time the antibacterial capacities of three organs of nalca against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Petiole (P), root (R) and flower (F) ethanolic extracts at three different concentrations (25, 50, 100 mg/mL) were evaluated by means of agar diffusion assay and MIC. The result showed that antibacterial activities are bacteria and concentration dependent, with root having the highest antimicrobial activity of the organs plant studied. Compared to commercial antibiotics, nalca extracts show promising control over Ps. aeruginosa. The main polyphenolics of the extracts were identified by UPLC-MS/MS, observing for the first time caffeic, coumaric and gallic acids presence in all samples, with quercetin and rutin determined in petiole and flower extracts only. Our results contribute to better understanding of nalca attributes as potential source of antibacterial compounds to be used in nutraceutical, cosmetic and food industry.

Polyphenolic distribution in organs of Argylia radiata, an extremophile plant from Chilean Atacama desert.

The polyphenolic distribution on different organs of Argylia radiata, an extremophile plant from the Atacama "Flowering Desert", is presented herein for the first time. For this purpose, the total phenolic content and antioxidant capacity of ethanolic extracts from leaves, tuberous root and flowers of different colors were evaluated. Orange and red flowers showed the highest polyphenolic and flavonoid content. The maximum anthocyanin concentration was found in red flowers and the antioxidant activity (FRAP) of extracts changed according to the organ. The UPLC-MS/MS analysis of the extracts allowed to identify 10 new polyphenols belonging to different families. Rutin was identified as the most abundant polyphenol in all plant organs, followed by quercetin and coumaric acid. Their role in plant response to abiotic and biotic stress, as well as their potential biotechnological application are discussed.

LC-MS/MS analysis of neonicotinoid insecticides: Residue findings in chilean honeys / LC-MS/MS análises de inseticidas neonicotinoides: Resíduos encontrados em méis chilenos

ABSTRACT Neonicotinoids are a relatively new generation of insecticides that have been used for control of pests such as aphids, leafhoppers and whiteflies. This paper presents for the first time a determination of residues of four neonicotinoid insecticides (acetamiprid, thiamethoxam, thiacloprid and imidacloprid) in Chilean honey using QuEChERS extraction and UHPLC-MS/MS analysis. The limits of detection and quantification found for all analytes ranging from 0.34 to 1.43 μg kg-1 and from 0.30 to 4.76 μg kg-1, respectively. The extraction using QuEChERS method provided recoveries over 79% and the precision showed coefficient of variation lower than 20%. These data are in agreement with the international criteria that recommend general recovery limits of 70 - 120%. Of the 16 samples analyzed, in three honey samples neonicotinoids pesticides were detected. These three samples were collected from the same geographical area (Rengo). Fruit and grain production characterize the province of Rengo. The analysis of the botanical origin of these honeys showed the absence of pollen grains of crops and the majority presence of pollen grains of weeds such as Medicago sativa, Galega officinalis and Brassica rapa, which could be associated with crops. Although the residue levels found were low, the results also confirm the actual occurrence of a transfer of neonicotinoid insecticides from exposed honeybees into honey.

RESUMO Os neonicotinóides são uma geração relativamente nova de inseticidas que tem sido utilizado para o controle de pragas, como pulgões, cigarrinhas e moscas brancas. Este artigo apresenta pela primeira vez a determinação de resíduos de quatro inseticidas neonicotinóides (acetamiprida, tiametoxam, tiaclopride e imidaclopride) em méis chilenos empregando para extração o método QuEChERS seguido de UHPLC-MS/MS. Foram encontrados limites de detecção e quantificação aceitáveis para todos os analitos variando de 0,34 a 1,43 μg kg-1 e de 0,30 a 4,76 μg kg-1, respectivamente. A extração usando o método QuEChERS proporcionou uma recuperação maior que 79% e a precisão do método não excedeu um coeficiente de variação de 20%. Esses dados estão de acordo com os critérios internacionais que recomendam limites gerais de recuperação de 70 - 120%. Das 16 amostras de mel analisadas foram detectados pesticidas neonicotinoides em três delas. Essas três amostras foram coletadas na mesma área geográfica (Rengo), a qual se caracteriza pela produção de grãos e frutas. A análise da origem botânica desses méis mostrou a ausência de grãos de pólen de espécies cultivadas nesta zona, porém mostrou uma presença majoritária de grãos de pólen de ervas daninhas, como Medicago sativa, Galega officinalis e Brassica rapa, as quais podem estar associadas a estes cultivos. Embora os níveis de resíduos neonicotinoides encontrados neste estudo são baixos, os resultados confirmam a ocorrência atual de uma transferência destes inseticidas ao mel das de abelhas expostas.

International Regulations of Propolis Quality: Required Assays do not Necessarily Reflect their Polyphenolic-Related In Vitro Activities.

Propolis has been proposed as a polyphenolic-rich natural product potentially able to be used for human consumption or even for medicinal proposes. To guarantee a minimum phenolic and flavonoid content and as consequence of their related-biological activities, international requirements of propolis quality are commonly applied. In this work we assessed phenolic and flavonoid contents of propolis; the antioxidant capacity (toward peroxyl radicals and hypochlorous acid); the ability to generate nitric oxide (NO); and, finally the antimicrobial activity of 6 propolis samples from the VI region of Chile. Our results show that the total phenolic and flavonoid content of propolis samples are not always in agreement with their polyphenolic-associated in vitro activities. For example, P03 and P06 samples showed the lowest (25 ± 4 GAE/g propolis) and the highest (105 ± 3 GAE/g propolis) total phenolic content, respectively. This was in agreement with flavonoid content and their Oxygen Radical Absorbance Capacity (ORAC) activity. However, this dependence was not observed toward HOCl, NO release and antimicrobial activity. Based on our results, we consider that, in order to guarantee the antioxidant or antimicrobial in vitro effects, the international regulations of propolis quality should contemplate the convenience of incorporating other simple analytical test such as ORAC or antimicrobial tests.

Determination of pesticides in river water using rotating disk sorptive extraction and gas chromatography-mass spectrometry.

The rotating disk sorptive extraction (RDSE) technique was applied to the determination of pesticides in aqueous samples. Pesticides of different polarities were considered in this study: chlorpyrifos, diazinon, fenvalarate, cyhalothrin, cypermethrin, lindane and malathion. The sorptive/desorptive behavior of the pesticides was studied using a rotating disk containing a polydimethylsiloxane (PDMS) phase on one of its surfaces. The analyte polarity was a significant factor in the extraction time; shorter extraction times were required for the more apolar pesticides. The optimum variables for the extraction of all analytes were: extraction time of 3h, sample volume of 25 mL, rotational velocity of the disk 1250 rpm, desorption time of 30 min using methanol. For pesticides with values of Log K(ow)>4, the extraction time can be reduced to 30 min for a quantitative extraction. Under these conditions, recoveries between 76% and 101% were obtained for the target pesticides, and the repeatability of the methodology, expressed as relative standard deviation, was determined to be between 10% and 20%. Additionally, the limits of detection of the analytes were lower than 3.1 µg L(-1). The extraction method developed using the RDSE was compared to a stir bar sorptive extraction (SBSE) under the same conditions. It can be observed that the extraction using the rotating disk offers higher recoveries because of its higher PDMS volume and its higher surface area to volume ratio that allows for improved mass transfer.