Artificial colorants raise health and environmental concerns, creating demand for sustainable natural alternatives. Blue pigments are particularly scarce due to their structural complexity and instability, with actinorhodin standing out among Streptomyces metabolites. A major challenge for actinorhodin production is to improve yields and reduce costs to enhance process feasibility. Discarded potato, an abundant and underutilized agricultural byproduct, is a nutrient-rich, low-cost substrate for microbial processes. Recently, a Streptomyces lydicus strain was reported to convert this byproduct into actinorhodin, but with relatively low production compared to traditional media and other Streptomyces species. This study aimed to optimize the conversion of discarded potato into actinorhodin-related blue pigments by S. lydicus PM7 and to evaluate biochemical responses that influence pigment production. A Plackett–Burman design identified temperature, agitation, pH, and KH2PO4 supplementation as significant factors among 11 tested variables. Optimization using a central composite face-centered design (CCD) within the framework of response surface methodology (RSM) increased pigment production up to 8000 mg L− 1. Model validation using point prediction identified optimal conditions of 30 °C, 180 rpm, an initial pH of 9, and 0.15 g L− 1 KH2PO4. Growth kinetics under optimized conditions revealed two exponential phases and shifts in α-glucosidase and α-amylase activities, indicating a possible sequential use of carbohydrates. Catalase activity coincided with the onset of exponential growth and pigment production. The optimized process yielded an 8.5-fold increase in pigment production, supporting the use of potato byproducts as an effective and low-cost fermentation substrate. The biochemical responses of S. lydicus PM7 provide initial insight into metabolic features associated with pigment formation. Overall, the findings establish a laboratory-scale proof of concept and a basis for future bioreactor-scale and application-oriented studies on microbial blue pigments by Streptomyces spp.

Despite the ethnobotanical significance of Chilean Colliguaja species, research on their biological activities and phytochemical composition remains limited. Among these species, Colliguaja odorifera Molina (Euphorbiaceae), traditionally used in folk medicine to alleviate toothaches, stands out for its potential for medicinal applications. This study aims to investigate the anti-inflammatory activity of the C. odorifera leaf extracts and their secondary metabolites isolated from the most active extract. A hydroalcoholic extract of C. odorifera leaves was prepared, and subsequently ethyl acetate (EA-E), n-butanol (B-E), and water (W-E) extracts were obtained by liquid–liquid partition. The extracts were first evaluated for their ability to inhibit lipoxygenase, and the most active extract was subsequently tested for hyaluronidase (HA) and secretory phospholipase A2 (sPLA2). The most active extract was EA-E, with IC50 values of 11.75, 31.09, and 6.60 µg/mL for anti-LOX activity, hyaluronidase, and sPLA2, respectively. This extract was analyzed by chromatography coupled to mass spectrometry and 1H and 13C NMR spectroscopy, allowing the identification, for the first time, of shikimic acid, gallic acid, methyl gallate, ethyl gallate, and a putative galloyl-luteolin. These results suggest that C. odorifera is a promising candidate for the development of natural alternatives to nonsteroidal anti-inflammatory drugs.

Cholinesterase inhibitors are an important therapeutic Alzheimer disease strategy. Consequently, many research groups have focused their studies on finding new target or bioactive molecules for controlling this neurodegenerative disorder. In this regard, prolyl oligopeptidase (POP) has been considered a target on diseases in which cognitive capabilities are affected. Therefore, the objective of this study was to evaluate Berberis microphylla G. Forst. alkaloidal extract, berberine, palmatine and jatrorrhizine inhibitory activity on POP, acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) by in silico and in vitro methodologies. It was found that B. microphylla alkaloidal extract was a potent inhibitor of AChE with an IC50 value of 3.62 μg/mL. To better understand the bioactivity of some alkaloids against AChE, BuChE and POP, a molecular docking approach was performed. The role of B. microphylla as source of AChE, BuChE and POP inhibitors is further discussed in this study.

Abstract Background Discarded potato is the most abundant potato waste and represents a worldwide disposal problem to the potato industry. This agricultural waste contains valuable nutrients that could be used as substrate to obtain diverse high value-added microbial products, such as biopigments. The aim of this work was to evaluate the use of discarded potato as a sole substrate source for producing blue pigments by Streptomyces lydicus PM7 through submerged fermentation. Results Initially, the traditional culture medium ISP2 was established as suitable for inoculum preparation, as it allowed high growth rates and consumption of ~ 75% reducing sugar, leading to 1.3 g L−1 dry biomass at 72 h of incubation. The formulated discarded potato broth (DPB) medium was evaluated together with five other traditional liquid culture media (potato dextrose broth, ISP2, ISP3, ISP4, and ISP5) for producing blue pigments by S. lydicus PM7. The highest blue pigment production was obtained by using DPB medium, reaching ~ 0.97 g L−1, followed by ISP5 (~ 0.36 g L−1). In terms of evaluating the concentration of discarded potato powder, the highest concentration of blue pigments was obtained with 16 g L−1, compared to concentrations of 4, 8, and 32 g L−1. In general, a notable increase in total proteins (~ 14 g L−1 in biomass; ~ 8 g L−1 in medium) and reducing sugars (~ 5 g L−1) on the fifth day of DPB fermentation was observed, at which time the production of blue pigments began. These data proved that S. lydicus PM7 is able to degrade potato wastes during submerged fermentation and to direct metabolism towards the formation of biopigments. Chromatographic analysis revealed that the main blue pigment produced by new strain in this complex medium is actinorhodin. Conclusions Discarded potato favored the production of blue pigments by S. lydicus PM7 under submerged fermentation, leading to final product concentration almost three times higher than others traditional Streptomyces culture media. To the best of our knowledge, this is the first report on the production of actinorhodin by the specie S. lydicus, as well as on this pigment synthesis based on an agricultural waste as a sole nutrient source for fermentation process. The findings showed that potato waste could be a potential byproduct for replacement of commercial culture media using for this same purpose. Graphical Abstract

The antimicrobial activity of metal nanoparticles obtained by biogenic routes has been extensively reported. However, their combined use with other antimicrobial formulations, such as essential oils, remains scarcely explored. In this work, a manganese-ferrite/silver nanocomposite (MnFe2O4/Ag-NC) was synthesized in a two-step procedure: first, MnFe2O4 nanoparticles were produced by a coprecipitation method, followed by in situ biogenic reduction of silver ions using Galega officinalis. MnFe2O4/Ag-NC was characterized using transmission electron microscopy (TEM), scanning electron microscopy equipped with an energy dispersive X-ray analyzer (SEM-EDX), and a vibrating sample magnetometer (VSM-SQUID). The antibacterial activity if MnFe2O4/Ag-NC was evaluated against Pseudomonas syringae by determining its minimum inhibitory concentration (MIC) in the presence of two essential oils: eucalyptus oil (EO) and garlic oil (GO). The fractional inhibitory concentration (FIC) was also calculated to determine the interaction between MnFe2O4/Ag-NC and each oil. The MIC of MnFe2O4/Ag-NC was eightfold reduced with the two essential oils (from 20 to 2.5 µg mL−1). However, the interaction with EO was synergistic (FIC: 0.5), whereas the interaction with GO was additive (FIC: 0.75). Additionally, a time-kill curve analysis was performed, wherein the MIC of the combination of MnFe2O4/Ag-NC and EO provoked a rapid bactericidal effect, corroborating a strong synergism. These findings suggest that by combining MnFe2O4/Ag-NC with essential oils, the necessary ratio of the nanocomposite to control phytopathogens can be reduced, thus minimizing the environmental release of silver.

The possibility of modifying terpene production in plants is a defensive strategy that has been studied in conjunction with their biosynthetic pathways. A biotic factor such as Arbuscular Mycorrhizal Fungi (AMF) could modify terpene production in Trifolium pratense L. In this work, the enzymatic production of monoterpenes in Superqueli INIA cultivar with two AMF was evaluated via HeadSpace-Gas Chromatography (HS-GC). A significant increase of (S)-limonene was found in plants inoculated with Claroideoglomus claroideum as well as with the AMF mix (genera Scutellospora, Acaulospora and Glomus). Moreover, significant increases in other monoterpenes such as (-)-β-pinene, myrcene, linalool, were observed. Results showed higher monoterpene production capacities in the Superqueli-INIA cultivar, suggesting the participation of monoterpene synthases (MTS). The significant rise of (S)-limonene in red clover plants inoculated with AMF suggests this strategy could be implemented in an agronomical manage for controlling the H. obscurus, the primary pest.

Trifolium pratense, is a forage found worldwide, but it is negatively impacted by the clover root borer, Hylastinus obscurus. Methanolic extraction has been reported for isolating formononetin from vegetal tissues, with an antifeeding effect on H. obscurus. However, this methodology is time-consuming and also extracts other secondary metabolites, whereas enzymatic assays can provide higher specificity. Hence, the objective of this work was to determine the optimal conditions in pH, temperature, and incubation time for the activity of isoflavone synthase via a response surface model. Once these parameters were optimized, the concentration of formononetin in cultivars and experimental lines of T. pratense was evaluated enzymatically. The results showed that the best condition for developing the enzymatic assay was pH 9.1 with an incubation at 34.5 degrees C for 155 min. The formononetin content fluctuated between 0.74 and 1.96 mg/g of fresh weight, where Precoz-3, Precoz-1, and Superqueli-INIA presented the highest production.

Abstract Alkaloid profiles from Amaryllis belladonna plants collected in Chile were examined by GC-MS to assess their inhibitory activity on acetylcholinesterase (AChE) using in vitro and in silico methodologies. The alkaloid extract was roughly separated by column chromatography on silica gel. AChE inhibitory activities from extracts and purified alkaloids were tested by the Ellman method and a molecular docking study was performed to assess the interaction between AChE and purified alkaloids. Sixteen alkaloids were found from hexane and chloroform extracts, and three were isolated and identified as buphanidrine, acetylcaranine and lycorine. Chloroform extract showed the greatest AChE inhibitory activity with IC50 value 8.89 µg/mL, whereas buphanidrine exhibited the highest inhibitory activity, with IC50 value 17.56 µg/mL. Inhibition kinetics showed that buphanidrine acts as a mixed inhibitor and molecular docking supports this inhibition mechanism. Overall, our study supports the potential use of A. belladonna as an alkaloid source with AChE inhibitory activity.

Potato waste was processed and used as a sole substrate for simultaneously producing antifungals and biopigments using Streptomyces spp. Out of three different Streptomyces isolates, strain SO6 stood out due to its ability to produce antifungals against economically important fungal phytopathogens and intracellular biopigments using potato waste powders without additional nutrients. This strain also showed the potential to secrete a broad range of enzymes for fermentation of eight sugars that could be involved in potato waste bioconversion. The results of the fermentation assay indicated that Streptomyces sp. strain SO6 degrades potato wastes during submerged fermentation, diminishing total dry weight and increasing reducing sugars from 0.3 to 3.6 mg·mL−1 and total proteins from 70.6 to 187.7 μg·mL−1. The results showed that Streptomyces strain SO6 was able to convert the potato waste into 0.96 mg·g−1 of diffusible antifungals and 1.75 mg·g−1 of reddish-purple biopigments. On the contrary, an absence of pigment production was observed during the fermentation of the commercial medium used as reference. According to our results, replacement of commercial culture media with available low-cost agroindustrial wastes for producing bioactive chemicals is a real opportunity to enhance the Streptomyces pigment production and antibiotic sustainability with cost-competitiveness. To our knowledge, this is the first report on the simultaneous production of biopigments and diffusible antifungal antibiotics produced by Streptomyces spp. using potato solid waste as the sole nutrient source.

Solanaceae is an important family of plants where many species of this family are source for food, industrial products, ornamental and medicinal uses. Within the family of Solanaceae, the genus Datura is one of the most interesting, in principle for its known medicinal and psychotropic uses against different pathologies. Multiple biological activities of Datura species have been documented. The species of the genus are attributed with insecticide, fungicide, antioxidant, antimicrobial, hypoglycemic, and immune response enhancing activity against cancer cells. These activities are related to the presence of different secondary metabolites such us: terpenoids, flavonoids, withanolides, tannins, phenolic compounds and tropane alkaloids, the main secondary metabolite of the genus Datura, being the most abundant atropine and scopolamine. The propose of this review is to identify the main phytochemical compounds isolated from the genus Datura and describe their biological activities associated to different secondary metabolites.

Galanthamine is an Amaryllidaceae-derived acetylcholinesterase inhibitor used to treat memory impairment in Alzheimer’s disease and vascular dementia. There is evidence that galanthamine, in addition to its effects on acetylcholinesterase, may enhance or inhibit brain nicotinic acetylcholine receptors, which could increase or decrease the therapeutic efficacy of galanthamine, respectively. Here, we evaluated the effects of galanthamine and two others Amaryllidaceae acetylcholinesterase inhibitors (haemanthamine and tazettine) analyzed by gas chromatography-mass spectrometry and identified by comparing their mass fragmentation patterns with literature and database NIST vs.2.0 on the agonist responses of brain nicotinic acetylcholine receptors α7, α3β4, (α4)2(β2)3 and (α4)3(β2)2. Using nicotinic acetylcholine receptors expressed heterologously in Xenopus oocytes, in conjunction with two-electrode voltage clamping, we found that galanthamine inhibits the function of nicotinic acetylcholine receptors assayed through a mix competitive and non-competitevely. Nicotinic acetylcholine receptor α7 were significantly more sensitive to inhibition (17±0.6 μM) than the heteromeric receptor, α3β4 (90 ± 3.4 μM). Neither haemanthamine nor tazettine were more potent than galanthamine.

Red clover (Trifolium pratense L.) is a perennial plant widely used as a forage resource for several animals. This plant is the exclusive host of Hylastinus obscurus (Marsham) which causes irreparable damages to the root system affecting their persistence. It has been reported that the presence of the isoflavonoid formononetin in roots of red clover could act as an antifeedant on H. obscurus. There are not studies related to the formononetin content in red clover roots to the antifeedant effect elicited by experimental lines and cultivar of red clover. Six red clover genotypes were investigated in both formononetin content and their respective antifeedant action. The results showed to Sabtoron High and Superqueli-INIA with both the highest formononetin content in red clover roots and antifeedant effect, allowing to suggest that this secondary metabolites could be used as a chemical factor for red clover plants. Moreover, a rapid methodology for searching red clover genotypes with high formononetin content is reported.

Red clover (Trifolium pratense L.) is a perennial plant widely used as a forage resource for several animals. This plant is the exclusive host of Hylastinus obscurus (Marsham) which causes irreparable damages to the root system affecting their persistence. It has been reported that the presence of the isoflavonoid formononetin in roots of red clover could act as an antifeedant on H. obscurus. There are not studies related to the formononetin content in red clover roots to the antifeedant effect elicited by experimental lines and cultivar of red clover. Six red clover genotypes were investigated in both formononetin content and their respective antifeedant action. The results showed to Sabtoron High and Superqueli-INIA with both the highest formononetin content in red clover roots and antifeedant effect, allowing to suggest that this secondary metabolites could be used as a chemical factor for red clover plants. Moreover, a rapid methodology for searching red clover genotypes with high formononetin content is reported.

Acetylcholinesterase is an important target for control of neurodegenerative diseases causing cholinergic signaling deficit. Traditionally, galanthamine has been used as an Amaryllidaceae-derived acetylcholinesterase inhibitor, although new Amaryllidaceae plants could serve as source for better acetylcholinesterase inhibitors. Therefore, the objective of this study was to characterize the alkaloid composition from bulbs of Rhodolirium andicola (Poepp.) Traub, a native Chilean Amaryllidaceae specie, and assess their inhibitory activity on acetylcholinesterase by in vitro and in silico methodologies. Alkaloidal extracts from R. andicola exhibited an inhibitory activity with IC50 values between 11.25 ±0.04 and 57.78 ± 1.92 μg/ml that included isolated alkaloid, galanthamine (2.3 ± 0.18 μg/ml), Additionally, 12 alkaloids were detected using gas chromatography-mass spectrometry and identified by comparing their mass fragmentation patterns with literature and database NIST vs.2.0. To better understand the bioactivity of isolated compounds and alkaloidal extracts against acetylcholinesterase, a molecular docking approach was performed. Results suggested that alkaloids such as lycoramine, norpluvine diacetate and 6α-deoxy-tazettine expand the list of potential acetylcholinesterase inhibitors to not only galanthamine. The role of R. andicola as a source for acetylcholinesterase inhibitors is further discussed in this study.

The insecticidal effects of five ethanolic extracts produced from three species of the genus Maytenus: M. boaria leaf (MBL), M. boaria bark (MBB), M. boaria seed (MBS), M. disticha leaf (MDL) and M. magellanica leaf (MML) were evaluated on the lady beetle Hippodamia convergens (Coleoptera: Coccinellidae) and on the pest of berry Aegorhinus superciliosus (Coleoptera: Curculionidae). The anti-feeding effects of the extracts on the latter were also evaluated. Residual application was used, with five concentrations for each species of insect and ten replications of each assay. To evaluate anti-feeding action in adult A. superciliosus, choice (C) and no-choice (NC) experiments were established to determine the percentage of leaf area consumed. The assays lasted for 120 hours, with the mortality and anti-feeding effect monitored every 24 hours. The highest percentage of mortality in the two insect species was recorded with the MBS ethanolic extract: H. convergens presented 82 %, with LC50: 32 mg/ml; while A. superciliosus presented 85 % in the choice assay and 86 % in the no-choice assay, with LC50: 23 mg/ml. In both assays, the mortality increased with exposure time, reaching its highest at 120 hours. The lowest mortality was obtained with MBB extract in choice (C) and with MML extract in no-choice (NC) assays. In the choice assay, the highest percentage of leaf area consumed was recorded with MBB extract, while in the no-choice assay the highest percentage of consumed was with MML extract, which presented higher values even than the control with no application. The lowest leaf percentage consumed, in both assays, was recorded with MBS extract at the highest concentrations (20 and 30 % w/v).

AimsThe aim of this study was to evaluate the synthesis of ligninolytic enzymes and some diffusible antifungal compounds by white-rot fungi (WRF) using peels or discarded potato as the sole nutrient source. Methods and ResultsThe strain Trametes hirsuta Ru-513 highlighted for its laccase activity (59533Ul(-1)), which is able to decolourize 87% of an anthraquinone dye using potato peels as the sole nutritional support. A native polyacrylamide gel of laccase proteins showed the presence of two isoenzymes, corresponding to proteins of 56 and 67kDa, which were detected by SDS-PAGE. The antifungal activity of ethyl acetate extracts was evaluated by the agar diffusion method, where Anthracophyllum discolor Sp4 and Inonotus sp. Sp2 showed the highest inhibition zones of Mucor miehei. The fungal extracts also inhibited Fusarium oxysporum and Botrytis cinerea growth, with inhibition zones of up to 18mm. The extract with the highest antifungal activity, from A. discolor Sp4 grown in discarded potato medium, was analysed using a gas chromatograph coupled to a mass spectrometer. Among the identified compounds, chlorinated aromatic compounds and veratryl alcohol were the most abundant compounds. ConclusionsThe results revealed the relevance of potato waste valorization for the sustainable production of ligninolytic enzymes and antifungal compounds. Significance and Impact of the StudyThis study reports the synthesis of ligninolytic enzymes and diffusible antifungal compounds by WRF using potato wastes as the sole nutrient source and suggests a relationship between the enzymatic activity and the synthesis of antifungal compounds. These compounds and the synthesis of halogen compounds by WRF using agro-industrial wastes have been poorly studied before.