Natural extracts against agricultural pathogens: A case study of Celtis australis L.

Plant extracts and other plant products have been used as an alternative to synthetic fungicides or an additional way to reduce their use. The choice of plant extracts and their application depends on their functional characteristics, availability, cost-effectiveness, and their impact on phytopathogens, and also on the environment. Therefore, the present study aims to assess the potential of Celtis australis methanolic extracts as source of compounds with antifungal activity. Methanolic extracts prepared from leaves and unripe mesocarps of C. australis collected from different localities of Montenegro (Podgorica-PG, Donja Gorica-DG, and Bar-BR) were evaluated for their phenolic compounds' composition as well as antifungal and cytotoxic properties. Obtained results revealed that extracts contain various bioactive constituents including phenolic acids, flavonoids, and their derivatives. The predominant phenolic acid was ferulic acid, identified in leaf samples from DG (187.97 mg/100 g dw), while isoorientin was the most abundant phenolic compound found in all examined samples. Regarding antifungal potential of the tested samples, all but one (prepared from mesocarp BR) possessed higher activity than Previcur, a commercial systemic fungicide intended to control seedlings. In vitro studies on HaCaT cell line showed that the extracts had no toxic effect toward the tested cell line. These results lead to the conclusion that methanolic extracts of C. australis can become an alternative to the use of synthetic fungicides in agriculture. Those extracts represent natural biodegradable fungicides and enable more efficient control of pathogenic fungi.

Antimicrobial Activity of Catechol-Containing Biopolymer Poly[3-(3,4-dihydroxyphenyl)glyceric Acid] from Different Medicinal Plants of Boraginaceae Family.

This study reports the antimicrobial activities of the biopolymers poly[3-(3,4-dihydoxyphenyl)glyceric acid] (PDHPGA) and poly[2-methoxycarbonyl-3-(3,4-dihydroxyphenyl)oxirane] (PMDHPO), extracted from the six plants of Boraginaceae family: Symphytum asperum (SA), S. caucasicum (SC), S. gr and iflorum (SG), Anchusa italica (AI), Cynoglosum officinale (CO), and Borago officinalis (BO) collected in various parts of Georgia. The study revealed that the antibacterial activities were moderate, and biopolymers from only three plants showed activities against all tested bacteria. Biopolymers from CO stems as well as SC and AI did not show any activity except low activity against a resistant P. aeruginosa strain, which was the most resistant among all three resistant strains. On the other hand, the antifungal activity was better compared to the antibacterial activity. Biopolymers from BO stems exhibited the best activities with MIC/MFC at 0.37-1.00 mg/mL and 0.75-1.5 mg/L, respectively, followed by those from SG stems. Biopolymers from SC and AI roots showed antifungal activities against all six fungi, in contrast to the antibacterial activity, while biopolymers from CO stems and SA roots had activities against four fungi and one fungus, respectively. The sugar-based catechol-containing biopolymers from BO stems demonstrated the best activities among all tested biopolymers against T. viride, P. funiculosum, P. cyclpoium var verucosum, and C. albicans (MIC 0.37 mg/mL). In addition, biopolymers from SG stems were half as active against A. fumigatus and T. viride as ketoconazole. Biopolymers from all plant materials except for CO stems showed higher potency than ketoconazole against T. viride. For the first time, it was shown that all plant materials exhibited better activity against C. albicans, one of the most dreadful fungal species.

Antimicrobial and Cytotoxic Activities of Selected Hieracium L. s. str. (Asteraceae) Extracts and Isolated Sesquiterpene Lactones.

Antimicrobial and cytotoxic activities were tested for dried MeOH extracts of Hieracium calophyllum (CAL), H. coloriscapum (COL), H. pseudoschenkii (PSE), H. valdepilosum (VAL) and H. glabratum (GLA) herbs (flowering aerial parts), their 2 sesquiterpene lactones (SLs) 8-epiixerisamine A and crepiside E, and dried CH2 Cl2 extract of H. scheppigianum (SCH) herb. In microdilution test, extracts showed activity on all tested microorganisms (8 bacteria, 10 fungi). The best effect was exhibited by SCH and CAL on Salmonella Typhimurium (MIC=1.7-2.5 mg/mL MBC=3.4-5.0 mg/mL), and SCH and VAL on Candida albicans (MIC=2.5 mg/mL MFC=5.0 mg/mL). SLs showed notable effect on all tested fungi Aspergillus ochraceus, Penicillium funiculosum, C. albicans and C. krusei (MIC=0.15-0.4 mg/mL MFC=0.3-0.8 mg/mL). In MTT test, extracts inhibited growth of all tested cancer cells (HeLa, LS174 and A549), with the best effect on HeLa (IC50 =148.1 µg/mL for SCH, and 152.3-303.2 µg/mL for MeOH extracts); both SLs were active against HeLa cells (IC50 =46.2 µg/mL for crepiside E and 103.8 µg/mL for 8-epiixerisamine A). Extracts and SLs showed good safety profile on normal MRC-5 cells.

Emerging Antifungal Targets and Strategies.

Despite abundant research in the field of antifungal drug discovery, fungal infections remain a significant healthcare burden. There is an emerging need for the development of novel antifungals since those currently available are limited and do not completely provide safe and secure protection. Since the current knowledge regarding the physiology of fungal cells and the infection mechanisms is greater than ever, we have the opportunity to use this for the development of novel generations of antifungals. In this review, we selected and summarized recent studies describing agents employing different antifungal mechanisms. These mechanisms include interference with fungal resistance, including impact on the efflux pumps and heat shock protein 90. Additionally, interference with virulence factors, such as biofilms and hyphae; the impact on fungal enzymes, metabolism, mitochondria, and cell wall; and antifungal vaccines are explored. The agents investigated belong to different classes of natural or synthetic molecules with significant attention given also to plant extracts. The efficacy of these antifungals has been studied mainly in vitro with some in vivo, and clinical studies are needed. Nevertheless, there is a large quantity of products employing novel antifungal mechanisms that can be further explored for the development of new generation of antifungals.

Chemical composition and biological activities of whole and dehulled hemp (Cannabis sativa L.) seeds.

This study aimed to determine a complete chemical composition of eight different varieties of whole hemp seeds and eight samples of commercial dehulled hemp seeds. We also evaluated the phenolic profiles and antioxidant, cytotoxic, and antimicrobial properties of hydromethanolic seed extracts. Whole hemp seeds contain much more fibre than dehulled hemp seeds, which contain more fat and protein. Sucrose and raffinose were the most abundant soluble sugars, and citric and oxalic acids were the most abundant organic acids. In the hydromethanolic hemp seed extracts, we detected the phenolic acids ferulic acid-hexoside and syringic acid. Whole hemp seed extracts exhibited better antioxidant activity than dehulled hemp seed extracts, especially in the TBARS assay. Cytotoxic activity against NCI-H460 cells was also observed. The dehulled hemp seed extracts displayed antibacterial activity, especially against Bacillus cereus, Listeria monocytogenes, and Enterococcus faecalis, and antifungal activity to a lesser extent.

Chemical and Biological Investigations of Allium scorodoprasum L. Flower Extracts.

This study was designed to investigate the impact of different extraction solvent systems on the chemical composition and biological activities of Allium scorodoprasum L. (Amaryllidaceae)-the medicinal plant that was traditionally used as a remedy in the medieval period in the Balkans. Targeted chemical analysis of nine different extracts was performed by UHPLC(-)HESI-QqQ-MS/MS. Antimicrobial and antibiofilm activities of the extracts were investigated on sixteen clinical isolates of bacteria, yeasts and dermatomycetes, all isolated from infected human skin and corneal formations. Cytotoxicity and wound-healing properties were tested on human immortalized keratinocytes (HaCaT cell line). Antioxidant activity was assessed by six different assays, while beneficial potential against certain neurodegenerative diseases and type 2 diabetes was determined in selected enzyme inhibition assays coupled with molecular modeling. The results showed that the obtained extracts were rich in phenolic compounds, especially flavonoid glycosides such as rutin and kaempferol 3-O-glucoside. All of the extracts showed antimicrobial, wound-healing, antioxidant and anti-enzymatic properties. This study is the first of its kind, linking the medieval medicinal use of wild-growing flowers of A. scorodoprasum with contemporary in vitro scientific approaches.

Study on the Potential Application of Impatiens balsamina L. Flowers Extract as a Natural Colouring Ingredient in a Pastry Product.

Flowers of the genus Impatiens are classified as edible; however, their inclusion in the human diet is not yet a common practice. Its attractive colours have stirred great interest by the food industry. In this sense, rose (BP) and orange (BO) I. balsamina flowers were nutritionally studied, followed by an in-depth chemical study profile. The non-anthocyanin and anthocyanin profiles of extracts of both flower varieties were also determined by high-performance liquid chromatography coupled to a diode array and mass spectrometry detector (HPLC-DAD-ESI/MS). The results demonstrated that both varieties presented significant amounts of phenolic compounds, having identified nine non-anthocyanin compounds and 14 anthocyanin compounds. BP extract stood out in its bioactive properties (antioxidant and antimicrobial potential) and was selected for incorporation in "bombocas" filling. Its performance as a colouring ingredient was compared with the control formulations (white filling) and with E163 (anthocyanins) colorant. The incorporation of the natural ingredient did not cause changes in the chemical and nutritional composition of the product; and although the colour conferred was lighter than presented by the formulation with E163 (suggesting a more natural aspect), the higher antioxidant activity could meet the expectations of the current high-demand consumer.

Cymbopogon citratus essential oil: an active principle of nanoemulsion against Enterococcus faecalis root canal biofilm.

Aim: The objective was to formulate and characterize the nanoemulsion based on Cymbopogon citratus oil, intended for use in infected teeth root canal therapy. The investigation of the antioxidant and antibiofilm potential toward Enterococcus faecalis was aimed as well. Materials & methods: Characterization of oil (by GC/MS analysis) and nanoemulsion (by dynamic light scattering instrument), and determination of antibacterial (by microdilution assay), antibiofilm (by crystal violet assay) and antioxidant properties (by 2,2-diphenyl-1-picryl-hydrazyl-hydrate and thiobarbituric acid assay methods) were provided. Antibiofilm efficacy of irrigation procedure including nanoemulsion was screened on extracted teeth (by CFU-counting assay). Results: Notable antibacterial and antibiofilm activity, both against forming and preformed biofilms of oil, was observed. Irrigation involved nanoemulsion showed remarkable antibiofilm potential. Both substances induced some antioxidant activity. Conclusion: Results encourage further research with the aim of application of the nanoemulsion in dental practice.

Chemical Composition and Bioactive Characterisation of Impatiens walleriana.

The attractive colour characteristics of the flowers of the species Impatiens walleriana have been arousing great interest in the food industry, which is looking for potential natural sources of colouring ingredients. In this sense, the present work focused on the chemical and bioactive characterization of pink and orange flowers of I. walleriana. The phenolic compounds were determined by HPLC-DAD-ESI/MS; in addition, different bioactivities (antioxidant, antimicrobial, anti-inflammatory and cytotoxicity) were also analysed. Both samples studied showed significant amounts of phenolic compounds, especially phenolic acids, flavonoids, and anthocyanins, which justifies the excellent performance in the different bioactivities studied. The orange variety, despite having a greater variety of phenolic compounds, showed a total amount of compounds lower than the pink variety. Overall, the flowers of I. walleriana emerge as a promising resource to be explored by the food industry.

Nutritional and phytochemical profiles and biological activities of Moringa oleifera Lam. edible parts from Guinea-Bissau (West Africa).

Moringa oleifera is an edible medicinal plant used to fight malnutrition in Africa. In this study, M. oleifera flowers, fruits and seeds from Guinea-Bissau were characterized for their nutritional composition and hydroethanolic and aqueous extracts were prepared to investigate the phenolic profiles and bioactivities. Seeds presented higher levels of proteins (~31 g/100 g dw), fat (~26 g/100 g dw) and flavan-3-ol derivatives, while carbohydrates, proteins, citric acid, and glycosylated flavonoids were abundant in fruits and flowers, these last samples also being rich in α-tocopherol (~18 mg/100 g dw). Some of the identified polyphenols had never been described in M. oleifera. In general, hydroethanolic extracts contained more polyphenols and were more active against lipid peroxidation, NO production, and tumour cells growth. Significant antimicrobial effects against the tested bacteria and fungi strains were displayed by both hydroethanolic and aqueous extracts. The M. oleifera potential to fight malnutrition and health issues was highlighted.

Antioxidant Extracts of Three Russula Genus Species Express Diverse Biological Activity.

This study explored the biological properties of three wild growing Russula species (R. integra, R. rosea, R. nigricans) from Serbia. Compositional features and antioxidant, antibacterial, antibiofilm, and cytotoxic activities were analyzed. The studied mushroom species were identified as being rich sources of carbohydrates and of low caloric value. Mannitol was the most abundant free sugar and quinic and malic acids the major organic acids detected. The four tocopherol isoforms were found, and polyunsaturated fatty acids were the predominant fat constituents. Regarding phenolic compounds, P-hydroxybenzoic and cinnamic acids were identified in the prepared methanolic and ethanolic extracts, which displayed antioxidant activity through the inhibition of thiobarbituric acid reactive substances (TBARS) formation and oxidative hemolysis; the highest activity was attributed to the R. nigricans ethanolic extract. This is the first report on the antibacterial and antibiofilm potential of the studied species, with the most promising activity observed towards Streptococcus spp. (0.20-0.78 mg/mL as the minimal inhibitory concentration, MIC). The most promising cytotoxic effect was caused by the R. integra methanolic extract on non-small cell lung cancer cells (NCI-H460). Therefore, due to the observed in vitro bioactive properties, the studied mushrooms arise as a source of functional ingredients with potential to be used in novel nutraceutical and drug formulations, which can be used in the treatment of various diseases and health conditions.

An Up-to-Date Review on Bio-Resource Therapeutics Effective against Bacterial Species Frequently Associated with Chronic Sinusitis and Tonsillitis.

Upper respiratory tract infections include inflammations of the nose, sinuses (sinusitis), pharynx (tonsillitis, pharyngitis) and larynx (laryngitis) with bacteria or viruses as the main cause of these conditions. Due to their repetitive nature, chronic respiratory infections represent a global problem which is often a result of improper treatment. If not treated adequately, these conditions may have serious consequences. On the other hand, mis - and overuse of antibiotics has reduced their efficiency and accelerated the development of resistant bacterial strains, which further complicates the treatment of infections. This literature review will focus on current knowledge regarding medicinal plants and mushrooms which have been traditionally used in the treatment of infections caused by chronic sinusitis and tonsillitis commonly linked to bacteria - Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes, Fusobacterium nucleatum, Haemophilus influenzae and Moraxella catarrhalis. The present literature overview might be considered as a starting point for the development of novel, natural antimicrobial products with potential practical use in the treatment of chronic tonsillitis and sinusitis.

Comparative investigation on edible mushrooms Macrolepiota mastoidea, M. rhacodes and M. procera: functional foods with diverse biological activities.

This study was oriented towards the investigation of the biological properties of three wild growing and edible Macrolepiota species (M. mastoidea, M. rhacodes and Macrolepiota procera) from Serbia. The results revealed that the mushrooms have a low caloric value; free sugars such as mannitol and trehalose were identified; oxalic and malic acids were predominant organic acids, while p-hydroxybenzoic and p-coumaric acids were identified as the main phenolic compounds. Also, they were a rich source of polyunsaturated fatty acids, which dominated over monounsaturated and saturated fatty acids. Three isoforms of tocopherols were identified and quantified: α-, ß-, and δ-tocopherol. Regarding biological properties, all three species exhibited antioxidant potential, antimicrobial potential and cytotoxic activity within the different tumour cell lines tested. This study indicates that these species are indeed functional foods, due to the fact that they are edible, consumable and hold different pharmacological activities.

Bioactive properties of greenhouse-cultivated green beans (Phaseolus vulgaris L.) under biostimulants and water-stress effect.

BACKGROUND: The scarcity of irrigation water is severely affecting global crop production. In this context, biostimulants are increasingly used as alternatives means against abiotic stress conditions. In this study, phenolic compounds composition and bioactive properties of common bean (Phaseolus vulgaris L.) plants grown under water stress conditions and biostimulants application were investigated. RESULTS: Sixteen individual phenolic compounds were detected in both pods and seeds with a notable difference in their compositional profile. A significant effect on phenolic compounds content and composition was also observed for the biostimulants tested. Regarding the antibacterial activity, pods of the second harvest and seed extracts showed significant efficacy against Bacillus cereus, especially in water-stressed plants, where all biostimulant treatments were more effective than positive controls. Moreover, all biostimulant treatments for seed extracts of water-stressed plants were more effective against Staphylococcus aureus compared with ampicillin, whereas streptomycin showed the best results. Extracts from pods of the second harvest from normally irrigated plants showed the best results against the fungi tested, except for Penicillium verrucosum var. cyclopium. Finally, no significant cytotoxic effects were detected. CONCLUSION: In conclusion, the biostimulants tested increased total phenolic compounds content compared with control treatment, especially in pods of the first harvest and seeds of water-stressed plants. Moreover, bioactive properties showed a varied response in regard to irrigation and biostimulant treatment. Therefore, biostimulants can be considered as a useful means towards increasing phenolic compounds content, and they may also affect the antimicrobial properties of pods and seeds extracts. © 2019 Society of Chemical Industry.

Antibacterial and Antibiofilm Activity of Flavonoid and Saponin Derivatives from Atriplex tatarica against Pseudomonas aeruginosa.

A new flavonoid glucoside derivative, patuletin 3 -O-(2- O-feruloyl)-ß-d-glucuronopyranosyl-(1→2)-ß-d-glucopyranoside, named atriplexin IV (1), and three new triterpenoid saponin derivatives, two sulfonylated, ß-d-glucopyranosyl-3 -O-(2- O-sulfo-ß-d-galactopyranosyl)-(1→2)-α-l-arabinopyranoside-30-alolean-12-en-28-oate (2), named atriplexogenin I, ß-d-glucopyranosyl-3- O-(2- O-sulfo-ß-d-galactopyranosyl)-(1→2)-α-l-arabinopyranoside)-30-hydroxyolean-12-en-28-oate (3), named atriplexogenin II, and ß-d-glucopyranosyl-3 -O-(ß-d-glucopyranosyl-(1→2)-ß-d-galactopyranosyl-(1→2)-α-l-arabinopyranoside)-30-alolean-12-en-28-oate (4), named atriplexogenin III, were isolated by silica gel column and semipreparative HPLC chromatography from the n-butanol extract of the salt marsh plant Atriplex tatarica. In addition, two known secondary metabolites, patuletin3 -O-ß-d-apiofuranosyl-(1‴→2″)-ß-d-glucopyranoside (5) and patuletin 3 -O-5‴- O-feruloyl-ß-d-apiofuranosyl-(1‴→2″)-ß-d-glucopyranoside (6), were isolated for the first time from A. tatarica. The structures of the isolated compounds were elucidated by 1D and 2D NMR, HRESIMS, IR, and UV data. Antibacterial activity by the microdilution method and antibiofilm activity against P. aeruginosa were assessed. Compound 5 possesses significant antibacterial activity, while the most potent antibiofilm agent is compound 2.

Ocimum basilicum var. purpurascens leaves (red rubin basil): a source of bioactive compounds and natural pigments for the food industry.

Ocimum basilicum var. purpurascens (red rubin basil) is a basil variety rich in anthocyanin compounds, commonly used in the food industry as an aromatic plant. In this study, the nutritional and chemical compositions of red rubin basil leaves were analysed, as well as, the antimicrobial activity and hepatotoxicity of their hydroethanolic extract. Carbohydrates were the main macronutrients present, with glucose being the major free sugar. Quinic acid was the most abundant organic acid, while γ-tocopherol was the highest tocopherol isoform found. α-Linolenic acid was the major fatty acid of the twenty identified compounds. Regarding polyphenols, twenty-six molecules were identified (thirteen non-anthocyanin and thirteen anthocyanin compounds), with rosmarinic acid being the main non-anthocyanin molecule and cyanidin-3-(6,6'-di-p-coumaroyl)-sophoroside-5-glcucoside the most abundant anthocyanin. These compounds could be related to the antimicrobial activity observed in this study. Thus, this variety could be considered a good source of value added molecules for the food industry.

Bioactive compounds content and antimicrobial activities of wild edible Asteraceae species of the Mediterranean flora under commercial cultivation conditions.

Nine wild edible species belonging to Astreaceae family, native to the Mediterranean basin were tested for their chemical composition (phenolic compounds, tocopherols, and organic acids) and antimicrobial activities over two growing periods, apart from Scolymus hispanicus and Hedypnois cretica which were tested for only one growing period. Flavonoids were the most abundant phenolic compounds in all the species, except for the case of Taraxacum species where significant amounts of chicoric acid were detected, while phenolic compounds content increased in the 2nd growing period by 4.6-397.4% for the tested species. α- and ß-tocopherols were the main tocopherols, apart from Taraxacum sp. where significant amounts of γ-and δ-tocopherols (18.32 and 16.31 µg/100 g fresh weight) were detected, while total tocopherols content either increased (Reicardia picroides, Picris echioides, Urospermum picroides, and Taraxacum officinale) or decreased (Hymenonema graecum, Sonchus oleraceus, Taraxacum sp.) in the 2nd growing period. Oxalic acid was the most abundant organic acid, with the highest content (972 mg/100 g fresh weight) being observed in H. graecum (L.) DC. in the 1st growing period. Moreover, with the exception of H. graecum and S. olearaceus, total organic acids content increased in the 2nd growing period. Significant antimicrobial activities were observed against Bacillus cereus, Salmonella typhimurium and Penicillium ochrochloron for all the studied species. In conclusion, the studied species showed great potential for commercial cultivation, while plant extracts could find use in the food industry as alternative food preservatives.

Chemical composition and bioactive properties of Sanguisorba minor Scop. under Mediterranean growing conditions.

Sanguisorba minor Scop. is a perennial plant native to the Mediterranean region which exhibits several medicinal activities. In the present study, plant growth, chemical composition, and antitumor and antimicrobial properties of S. minor plants were evaluated under different growing conditions. In particular, plants were grown on different substrates, namely (A) peat, (B) peat : perlite (1 : 1) and (C) peat : perlite (2 : 1). The dry weight of the aerial parts and roots was higher for the peat treatment (A), whereas plant growth was severely affected in the peat : perlite (1 : 1) treatment (B). The major detected sugars were fructose and glucose, while the peat : perlite (2 : 1) treatment resulted in a significant increase of α-tocopherol, glucose and total sugars content, especially in the aerial parts. Oxalic acid and citric acid were the major organic acids detected, with a varied effect of growth substrate on organic acid profile. Growth substrate and plant part also had a significant effect on fatty acid composition, especially on linoleic acid and α-linolenic acid content which was higher in the peat : perlite (1 : 1) treatment in both aerial parts and roots. An impact on the composition of phenolic compounds was also observed, where the plants grown on peat : perlite (2 : 1) and peat : perlite (1 : 1) substrates had the highest content of individual and total phenolic compounds in their aerial parts and roots, respectively. Moreover, roots contained significantly higher amounts of phenolic compounds than the aerial parts. Moreover, plant extracts exhibited antiproliferative activity against four tumor cell lines (HeLa, HepG2, MCF-7 and NCI-H460) and a primary culture of porcine liver cells (PLP2), as well as significant antimicrobial properties. In conclusion, S. minor presented significant bioactive properties, while growth substrates affected the nutritional value, chemical composition, antitumor and antimicrobial properties of the species which could be probably attributed to the higher phenolic compound content and different compositions of phenolic compounds. Therefore, although the species is commonly found in the Mediterranean region, it is underexploited yet and its plant tissues could be a potential source of natural bioactive compounds with further use in pharmaceutical and medicinal applications.

Optimization of the Extraction Process to Obtain a Colorant Ingredient from Leaves of Ocimum basilicum var. purpurascens.

Heat-Assisted Extraction (HAE) was used for the optimized production of an extract rich in anthocyanin compounds from Ocimum basilicum var. purpurascens leaves. The optimization was performed using the response surface methodology employing a central composite experimental design with five-levels for each of the assessed variables. The independent variables studied were the extraction time (t, 20⁻120 min), temperature (T, 25⁻85 °C), and solvent (S, 0⁻100% of ethanol, v/v). Anthocyanin compounds were analysed by HPLC-DAD-ESI/MS and the extraction yields were used as response variables. Theoretical models were developed for the obtained experimental data, then the models were validated by a selected number of statistical tests, and finally, those models were used in the prediction and optimization steps. The optimal HAE conditions for the extraction of anthocyanin compounds were: t = 65.37 ± 3.62 min, T = 85.00 ± 1.17 °C and S = 62.50 ± 4.24%, and originated 114.74 ± 0.58 TA mg/g of extract. This study highlighted the red rubin basil leaves as a promising natural matrix to extract pigmented compounds, using green solvents and reduced extraction times. The extract rich in anthocyanins also showed antimicrobial and anti-proliferative properties against four human tumor cell lines, without any toxicity on a primary porcine liver cell line.

Enhancing the antimicrobial and antifungal activities of a coloring extract agent rich in betacyanins obtained from Gomphrena globosa L. flowers.

Although less explored than beetroot (Beta vulgaris L.), the flowers of Gomphrena globosa L. are a very suitable source of betacyanins with strong pigmentation features, together with many other desirable bioactive properties. Thus, the aim of this study was to enhance the antimicrobial and antifungal activities of a pigmented extract obtained from G. globosa flowers by ultrasound assisted extraction (UAE). The procedure was supported with the application of the response surface methodology, a robust optimization technique that allows to study jointly the effects of several variables and responses. To enhance the antimicrobial (Bacillus cereus, Listeria monocytogenes, Escherichia coli and Salmonella typhimurium) and antifungal (Aspergillus flavus, Aspergillus niger, Penicillium ochrochloron and Penicillium verrucosum) activities, the responses were evaluated in terms of the concentrations needed to obtain minimum inhibitory (MIC), minimum bactericidal (MBC) and minimum fungicidal (MFC) concentrations. It was found that the optimal UAE conditions were 10.8 min, 410.5 W, 57.8% of ethanol, and 5 g L-1 of the solid-liquid ratio providing the following response values: (1) from the studied species of bacteria, the MIC ranged from ∼0.15 to 0.35 g L-1 and the MBC ranges were ∼0.30 to 0.65 g L-1; and (2) from the studied fungus species, the MIC ranged from ∼0.20 to 0.30 g L-1 and the MFC ranges were ∼0.40 to 0.65 g L-1. The antibacterial activity dose levels were lower than the antifungal ones. In conclusion, the results obtained in this study highlight extracts from G. globosa flowers as natural sources of betacyanins with application as food colorants with important antimicrobial and antifungal activities.