Journal of the Chilean Chemical Society

ECOTOXICOLOGICAL EVALUATION OF THE INSECTIVCIDE PROTEINS CRY1FA AND VIP3A IN TRANSGENIC MAIZE FR-BT1 AND V20(S2) ON NON-TARGET ORGANISMS

2026-08-02T15:29:52+00:00

The corn borer (Spodoptera frugiperda) is a major pest causing significant damage to corn crops due to its difficult management. As an alternative for pest control, the Genetic Engineering and Biotechnology Center of La Habana in Cuba (CIGB) developed the transgenic corn varieties FR-Bt1 and V20(S2), which are resistant to the corn borer due to the over expression of two insecticidal proteins Cry1Fa and Vip3A. However, it is crucial to assess the risks associated with the expression of these proteins on non-target organisms present in the maize ecosystem. In this study, an ecotoxicological evaluation was conducted to assess the toxicity of Cry1Fa and Vip3A proteins, both in their active and inactive forms, as well as plant samples from transgenic and conventional corn crops, on bioindicator species of ecosystems. Organisms were exposed to safe concentrations of insecticidal proteins and plant samples via oral administration. Terrestrial organisms included beneficial insects (Chrysopa exterior and Trichogramma pintoi), pollinators (Apis mellifera), and the decomposer earthworm (Eisenia andrei), while aquatic species included fish (Brachydanio rerio) and frogs (Osteopilus septentrionalis). Toxicity signs and mortality were evaluated in these biomodels. The results showed no physiological, behavioral, or mortality alterations in the species tested. Overall, the insecticidal proteins expressed in the transgenic corn crops FR-Bt1 and V20(S2), as well as the plant samples, were not toxic to the bioindicator species under laboratory conditions.

DETERMINATION IN VITRO OF THE ANTIBACTERIAL ACTIVITY OF CHILEAN NATIVE ESSENTIAL OILS AGAINST PSEUDOMONAS SYRINGAE PV. ACTINIDIAE AND PSEUDOMONAS SYRINGAE PV. SYRINGAE ISOLATES

2026-08-02T15:29:52+00:00

Pathogenic bacteria Pseudomonas syringae pv. actinidiae (Psa) and Pseudomonas syringae pv. syringae (Pss) causes bacterial canker disease in kiwifruit orchards. In this regard antibacterial activities of Chilean native species Peumus boldus (Molina), Laurelia sempervirens (Ruiz & Pav. Tul.), Cryptocarya alba (Mol) Looser essential oils, α-pinene, eucalyptol and p-cymene showed efficacy against Psa and Pss strains by disc diffusion method and liquid culture assay. The P. boldus essential oil at 7.0 mg/disc was significantly more effective than L. sempervirens and C. alba essential oil at the same concentration, using streptomycin as positive control. Additionally, α-pinene and p-cymene showed a remarkable effect in the inhibition of all strains tested at the same concentration. On the other hand, p-cymene showed a notable antibacterial activity similar to streptomycin against Psa. The P. boldus essential oils minimal inhibitory concentrations (MIC) and minimal bactericidal (MBC) concentration ranged from 312.5 to 625 ppm against Psa. The efficacy of P. boldus EO was comparable to streptomycin in in vitro conditions, offering potential as a sustainable alternative to integrated control of Psa in the kiwifruit industry.

PRODUCTION OF METALLIC NANOPARTICLES FROM FUNGAL METABOLITES OF Gymnopilus junonius WITH ANTIMICROBIAL POTENTIAL

2026-08-02T15:29:52+00:00

The aim of this study was to evaluate the antimicrobial properties of silver nanoparticles (AgNPs) synthesized using the metabolites of the fungus Gymnopilus junonius, grown on stumps of Pino spp. and Eucalipto spp. as substrates. Samples were collected from three locations in the Biobío Region to extract their metabolites and optimize the biosynthesis of nanoparticles, which were characterized using UV-VIS spectroscopy, TEM, and FTIR. AgNPs derived from pine showed a smaller average size (10–15 nm) and greater uniformity, whereas those from eucalyptus displayed a broader size range (20–30 nm), highlighting the impact of different metabolites on the synthesis process. Antimicrobial tests revealed that both AgNPs were effective against gram-positive (Staphylococcus aureus) and gram-negative bacteria, as well as pathogenic fungi (Candida albicans and C. glabrata). However, AgNPs derived from pine demonstrated greater efficacy, likely due to their smaller size, which facilitates interaction with microbial membranes. This study highlights the capability of the fungus Gymnopilus junonius as a sustainable biofactory for producing nanoparticles with antimicrobial properties, emphasizing its potential application in microbial infection treatments and agriculture. Furthermore, this approach provides an eco-friendly alternative to the use of conventional chemical agents in nanoparticle synthesis.

ANTIMICROBIAL ACTIVITIES OF MYCORRHIZIN A PRODUCED BY LIQUID FERMENTATIONS OF AN ENDOPHYTIC PEZICULA CINNAMOMEA (NA-78) ISOLATED FROM NOTHOFAGUS ALPINA IN CHILE

2026-08-02T15:29:52+00:00

The present work is part of a program aimed at searching for bioactive from Chilean fungi. In this opportunity, we report the study on Chilean endophytic fungi, identified as Pezicula cinnamomea (strain Na-78) isolated from Nothofagus alpina, collected in the Ñuble Region-Chile. Mycelial submerged fermentations of P. cinnamomea-78 were performed. Two types of extracts were obtained, EtOAc-extract (liquid phase) and MeOH-extract (mycelial phase). Plate diffusion assay showed that EtOAc-extract was more active than MeOH-extract. A large-scale fermentation of P. cinnamomea-78 and chromatographic and spectroscopic methods allowed to isolate and identify, from EtOAc-extract, a bioactive compound named Mycorrhizin A. This compound showed antibacterial activity against B. cereus, S. aureus and S. aureus MRSA. Also, Mycorrhizin A was active toward filamentous fungi, such as A. niger, B. cinerea and F. oxysporum. Assays showed that Mycorrhizin A exhibited a bactericidal effect against B. subtilis and S. aureus at 10 µg/mL and bacteriostatic activity at 25 µg/mL. Also, Mycorrhizin A showed a fungistatic/fungicidal effect toward A. niger and B. cinerea at 25-100 µg/mL, respectively. The study established that Mycorrhizin A was bacteriostatic against S. aureus MRSA and fungistatic against F. oxysporum at 200 µg/mL. This study constitute the first report of P. cinnamomea for the genus Nothofagus. Our research has revealed a new antibacterial activity of mycorrhizal A and has broadened the spectrum of antifungal activity.

NOVEL BRASSINOSTEROID ANALOGS WITH BENZYL FUNCTIONS AT C-22 AND BIOLOGICAL EVALUATIONS IN THE RICE LAMINA INCLINATION TEST

2026-08-02T15:29:52+00:00

Brassinosteroids (BRs) are an important group of polyhydroxylated natural occurring steroidal phytohormones found in the plant kingdom in extremely low amounts. Due to the low concentrations in which these compounds are found, much effort has been dedicated to synthesizing these compounds or their structural analogues using natural and abundant sterols. In this work we report the synthesis of seven new brassinosteroid analogs, obtained from a derivative of dinorcholenic acid 3b-acetate, with benzyl functions at side chain (C-22 positions) and o-p-substituted chlorine and fluorine. Plant growth activities of these compounds were evaluated by Rice Lamina Inclination Test (RLIT). Results show that unsubstituted benzylated compound is less active than the benzoylated analog. However, the incorporation of a fluorine atom on -para position of aromatic ring, produces a significant increase in biological activity and p-F benzyl analog becomes three times more active than the respective benzoylated compound. Interestingly, substitution in the aromatic ring with F or Cl atom induce important changes on activity, which strongly depends on the substitution position in the benzylated function.

INTEGRATIVE IN VITRO AND IN SILICO ANALYSIS OF FATTY ACID BIOCONVERSION: ELUCIDATING METABOLIC AND ENZYMATIC MECHANISMS IN LINOLEIC ACID TRANSFORMATION BY PROBIOTIC LACTIPLANTIBACILLUS PLANTARUM HMX2

2026-08-02T15:29:52+00:00

Probiotic bacteria transform linoleic acid (LA) into bioactive lipid derivatives, offering significant potential for industrial applications and health benefits. This study aimed to elucidate the metabolic pathways and enzymatic interactions involved in the biotransformation of linoleic acid by Lactiplantibacillus plantarum HMX2 using both experimental and computational approaches. Growth kinetics were monitored across varying substrate concentrations (2%–10%), while gas chromatography-mass spectrometry (GC-MS) was employed to identify key biotransformation metabolites. In silicoanalyses included protein identification, molecular docking, and molecular dynamics (MD) simulations to determine enzyme-substrate binding affinity and interaction stability. L. plantarum HMX2 demonstrates unique metabolic plasticity, producing a broader range of fatty acid derivatives than LAB strains, making it a promising candidate for biotechnological applications related to lipid metabolism. Further research should focus on experimental validation through recombinant expression and kinetic profiling of the identified enzymes to confirm their specific roles in linoleic acid biotransformation and to optimize industrial-scale applications.

NANOSTRUCTURED CUPRIC OXIDE AS A PHOTOCATALYST IN THE DECONTAMINATION OF ORGANIC DYES: A REVIEW

2026-08-02T15:29:52+00:00

The issue of freshwater contamination is a global concern, prompting individuals to seek effective solutions for restoring polluted water environments. Organic dyes are among the various pollutants contributing to this problem. Many of these dyes, commonly used in different industries, are toxic and carcinogenic, posing significant risks to both humans and marine ecosystems. Consequently, the environmental impact of organic dyes has been a focal point of extensive research in recent years. Heterogeneous photocatalysis has emerged as a highly effective method for breaking down atmospheric and aquatic organic contaminants, particularly organic dyes. Among the photocatalysts, CuO nanostructures are noteworthy due to their abundance, cost-effectiveness, narrow bandgap, excellent chemical and photochemical stability, and straightforward synthesis. The primary goal is to review the application of copper oxide photocatalysts in decontaminating various organic dyes, with a focus on Methylene blue. The photocatalytic ability of CuO in degrading MB and other dyes is limited, but it improves significantly in the presence of H2O2. Furthermore, CuO nanocrystals with greater exposure of facets {100} and {-121}, and shapes like nanoribbons, ̅enhance their photocatalytic efficiency against MB and other dyes. Additionally, doping CuO with other metallic oxides MxOy, metals M°, and supports such as Graphene, Bentonite, Cellulose carbon nanosheets, and MgAl-layered double hydroxides can further enhance its photocatalytic performance. In many of these nanocomposites, the formation of heterojunctions enhances charge separation of e̅ and h+, leading to increased production of OH× radicals.

SECONDARY PLANT METABOLITES IN OCEANIC ISLANDS: CONTRIBUTIONS OF PROFESSOR MARIO SILVA OSORIO TO UNDERSTANDING THE CHEMISTRY AND EVOLUTION OF ENDEMIC PLANTS OF THE ROBINSON CRUSOE (JUAN FERNANDEZ) ARCHIPELAGO

2026-08-02T15:29:52+00:00

Oceanic islands are important natural laboratories in which to investigate patterns and processes of plant evolution. As plant colonists arrive and speciate in a new island environment, changes in secondary plant metabolites take place. These compounds have a major role for defense against herbivores, especially insects. Due to a reduction (or absence) of herbivores in a new oceanic island, loss of defensive compounds might be expected. Another concern is whether secondary metabolites track phylogeny in the islands in the same way as does morphology or DNA. These research interests have been focused on the endemic plants of the Robinson Crusoe (Juan Fernández) Archipelago, a Chilean national park. In collaboration with Professor Mario Silva of the University of Concepciόn, we have made comparisons among endemic species of the islands as well as with close mainland relatives. Data have revealed that the patterns of secondary products resulting from phylogeny within the islands have in general paralleled those from morphology as well as more recent DNA data. Testing the hypothesis of a reduction in secondary products within endemic island species has shown both reductions and gains in diversity of flavonoids in different genera. These investigations were completed successfully with the outstanding collaboration of Silva, who spearheaded chemical analyses of many island plants and continental relatives. It was a privilege to have worked with him as a scientist and to have known him as a friend.

ANOMALOUSLY HIGH ARSENIC IN LLUTA VALLEY SOILS, NORTHERN CHILE: A NATURAL PHENOMENON OR ANTHROPOGENIC POLLUTION?

2026-08-02T15:29:52+00:00

The Lluta river basin (northern Chile) is characterized by anomalously high arsenic contents in soils, typically attributed to natural volcanic processes. The primary objective of this research was to evaluate the impact of a historical tailings dam on the elemental content of the Lluta basin soil. The 95^th percentiles of total soil contents of arsenic, copper, lead, and zinc upstream of the tailings were 197, 17, 438, and 33 mg kg^-1, respectively, representing the background contents of elements in the basin’s soils. A Kruskal-Wallis analysis comparing arsenic contents in soils upstream and downstream of the tailings provided convincing evidence of anthropogenic pollution originating from the dam. This observation is further supported by elevated levels of other chalcophiles (lead and zinc) and increased electrical conductivity in the soil. In conclusion, although the Lluta basin soil has naturally occurring high arsenic content, acid drainage from the tailings is causing soil pollution, requiring an urgent intervention by the Chilean environmental authorities.