Lautaro Taborga

A series of ten geranylated benzaldehydes (11–20) was designed, synthesized via Suzuki cross-coupling for the C–C series and S_N2 substitution for the C–O derivatives, and structurally characterized. The antifungal activity of all compounds against the phytopathogens Botrytis cinerea and Phytophthora cinnamomi, two important plant pathogens associated with substantial agricultural and economic losses worldwide, was evaluated in vitro using a mycelial growth inhibition assay. Dose–response treatment of the data indicates that (E)-2-((3,7-dimethylocta-2,6-dien-1-yl)oxy)-5-hydroxybenzaldehyde (19) is the most active compound exhibiting EC₅₀ values of 83 µg/mL and 7.34 µg/mL against B. cinerea and P. cinnamomi, respectively. To gain insight into the molecular basis of the observed antifungal activity, molecular docking studies were performed targeting the active site of succinate dehydrogenase (SDH, PDB ID: 2FBW), a key enzyme in the mitochondrial respiratory chain and a validated fungicide target. The calculated docking scores ranged from −6.0 to −7.5 kcal/mol, with compound 19 showing the highest binding affinity. Docking analysis reveals that compound 19 is stabilized within the SDH binding pocket through a network of hydrogen bonding and π–cation interactions involving the heme prosthetic group and key amino acid residues, providing a plausible structural rationale for its high antifungal activity, particularly against P. cinnamomi.

Residential wood combustion in energy-vulnerable contexts creates a critical trade-off between thermal comfort and air quality. Conventional emission control technologies often rely on active secondary systems or complex electronic controls that require electricity and maintenance, limiting their adoption in developing regions. This study evaluates a novel stove design integrating Inert Porous Media (IPM) structurally within the combustion chamber to act as a passive primary measure for pollutant reduction. Experimental tests following an adapted EPA Method 5G protocol compared a commercial 11 kW reference stove against an IPM-integrated prototype. Results demonstrate that IPM integration induces thermal reordering that favors secondary air preheating and intensifies heat transfer through enclosure walls. This mechanism increased thermal efficiency by 23% and useful thermal power by 67% while reducing exhaust gas temperatures by 6% and raising external wall temperatures by 18%. Crucially, the prototype achieved a 57% reduction in particulate matter emission rates and a 65% decrease in mass emission factors across the entire granulometric range from TSP to PM1 despite operating at a 15.5% higher burning rate. Normalization by useful energy output revealed systematic reductions of 26% for particulate matter and 33% for carbon monoxide per gigajoule of heat delivered. These findings confirm that structural IPM integration decouples combustion intensification from pollutant formation. The proposed technology offers a scalable and electricity-free solution to reconcile residential heating needs with atmospheric decontamination goals in developing regions.

Las naftoquinonas son compuestos orgánicos con amplia relevancia biológica y aplicaciones en química médica y agrícola. En este trabajo se describe la síntesis de los derivados conocidos de lawsona (1), 2‑acetoxi (2) y 2‑metoxi (3) de, junto con cuatro nuevos compuestos O‑acilados (4–7) obtenidos mediante reacciones de O‑alquilación y O‑acilación. Los productos fueron caracterizados por FT‑IR, RMN 1D y 2D, y espectrometría de masas de alta resolución (EMAR), confirmando sus estructuras. Los rendimientos oscilaron entre 49,3 % y 89,2 %, observándose variaciones atribuibles a la naturaleza del grupo acilo. Estos resultados establecen la base para estudios posteriores orientados a evaluar la actividad antifúngica frente a fitopatógenos de importancia agrícola.

The phytopathogenic fungus Botrytis cinerea, which causes gray mold disease, has become a limiting factor on agricultural production. B. cinerea field control is made mainly using chemical fungicides, which has led to the spreading of resistant populations of this fungus. Thus, the quest of new fungicides molecules has been focused on synthesis of natural product-inspired compounds. The main aim of this work is to synthesize prenylated phenol derivatives and to assess their potential application as antifungal agents with minimal phytotoxic effects. Thus, new prenylphenols (4, 5, and 7) have been obtained by microwave irradiation with yields ranging from 2.4% to 42.9%, whereas compounds 8 and 9 were synthesized with yields of 25.6% and 54.1%, respectively. The effect of different concentrations of these compounds on B. cinerea spore germination, and their phytotoxic effect on tomato (Solanum lycopersicum L.) seed germination and root growth, were evaluated. Obtained results indicate that biological activities of all tested compounds are concentration-dependent. Interestingly, compound 7 exhibits the highest antifungal activity against B. cinerea spores (IC₅₀ < 50 µg/mL) with minimal phytotoxicity on tomato seed germination and root growth. In contrast, compounds 2 and 3 are active against spores (IC₅₀ = 461 and 325 µg/mL, respectively) but, at the same time, their phytotoxicity is important at the highest concentrations. These results indicated that the presence of hydroxyl and methyl substituents on the aromatic ring of these compounds induces variations in biological activities, and compound 7 could be a promising candidate as a sporicidal agent.

Flavonoids are an abundant class of naturally occurring compounds with broad biological activities, but their limited abundance in nature restricts their use in medicines and food additives. Here we present the synthesis and determination of the antibacterial and antioxidant activities of twenty-two structurally related flavonoids (five of which are new) by scientifically validated methods. Flavanones (FV1–FV11) had low inhibitory activity against the bacterial growth of MRSA 97-7. However, FV2 (C5,7,3′,4′ = OH) and FV6 (C5,7 = OH; C4′ = SCH₃) had excellent bacterial growth inhibitory activity against Gram-negative E. coli (MIC = 25 µg/mL for both), while Chloramphenicol (MIC = 25 µg/mL) and FV1 (C5,7,3′ = OCH₃; 4′ = OH) showed inhibitory activity against Gram-positive L. monocytogenes (MIC = 25 µg/mL). From the flavone series (FO1–FO11), FO2 (C5,7,3′,4′ = OH), FO3 (C5,7,4′ = OH; 3′ = OCH₃), and FO5 (C5,7,4′ = OH) showed good inhibitory activity against Gram-positive MRSA 97-7 (MIC = 50, 12, and 50 µg/mL, respectively), with FO3 being more active than the positive control Vancomycin (MIC = 25 µg/mL). FO10 (C5,7= OH; 4′ = OCH₃) showed high inhibitory activity against E. coli and L. monocytogenes (MIC = 25 and 15 µg/mL, respectively). These data add significantly to our knowledge of the structural requirements to combat these human pathogens. The positions and number of hydroxyl groups were key to the antibacterial and antioxidant activities.

Pintoa chilensis is a shrub with yellow flowers that reach up to two meters high, endemic of the Atacama Region in Chile. This species grows under special environmental conditions such as low altitude, arid areas, and directly sun-exposed habitats. In the present study, ethanolic extract was obtained from fruits of P. chilensis, and then partitioned in solvents of increasing polarity to obtain five fractions: hexane (HF), dichloromethane (DF), ethyl acetate (AF), and the residual water fraction (QF). The antioxidant activity of extracts was evaluated by using the DPPH, ABTS, and FRAP methods. The results show that the antioxidant capacity of P. chilensis is higher than that reported for other plants growing in similar environments. This effect is attributed to the highest content of flavonoids and total phenols found in P. chilensis. On the other hand, the cell viability of a breast cancer cell line (MCF-7) and a non-tumor cell line (MCF-10A) was assessed in the presence of different extract fractions. The results indicate that the hexane fraction (HF) exhibits the highest cytotoxicity on both cell lines (IC₅₀ values equal to 35 and 45 µg/mL), whereas the dichloromethane fraction (DF) is the most selective one. The GC–MS analysis of the dichloromethane fraction (DF) shows the presence of fatty acids, sugars, and polyols as major components.

Botrytis cinerea is a phytopathogenic fungus that causes serious damage to the agricultural industry by infecting various important crops. 2-allylphenol has been used in China as a fungicide for more than a decade, and it has been shown that is a respiration inhibitor. A series of derivatives of 2-allylphenol were synthesized and their activity against B. cinerea was evaluated by measuring mycelial growth inhibition. Results indicate that small changes in the chemical structure or the addition of substituent groups in the aromatic ring induce important variations in activity. For example, changing the hydroxyl group by methoxy or acetyl groups produces dramatic increases in mycelial growth inhibition, i.e., the IC₅₀ value of 2-allylphenol decreases from 68 to 2 and 1 μg mL⁻¹. In addition, it was found that the most active derivatives induce the inhibition of Bcaox expression in the early stages of B. cinerea conidia germination. This gene is associated with the activation of the alternative oxidase enzyme (AOX), which allows fungus respiration to continue in the presence of respiratory inhibitors. Thus, it seems that 2-allylphenol derivatives can inhibit the normal and alternative respiratory pathway of B. cinerea. Therefore, we believe that these compounds are a very attractive platform for the development of antifungal agents against B. cinerea.

Fungi are a prolific source of bioactive molecules. During the past few decades, many bioactive natural products have been isolated from marine fungi. Chile is a country with 6435 Km of coastline along the Pacific Ocean and houses a unique fungal biodiversity. This review summarizes the field of fungal natural products isolated from Antarctic and Chilean marine environments and their biological activities.

In this work, the antioxidant activity of the hydro-ethanolic extracts of the leaves, flowers, and aerial parts of Steiractinia aspera Cuatrec, both fresh and post-distillation, was evaluated by ABTS^+·, FRAP, H₂O₂ and DPPH assays. The cytotoxic activity was evaluated in MCF-7, MCF-10A and HT-29 cell lines. The hydro-ethanolic extracts were obtained by matrix solid-phase dispersion (MSPD) and ultrasound-assisted solvent extraction (SE). The fresh-leaf MSPD extract had the highest antioxidant activity, and the post-distillation leaf ultrasound-assisted SE extract had the highest cytotoxicity in the MCF-7 breast cancer cell line, although not selective, which was evaluated by sulforhodamine B assay. On the other hand, ROS was evaluated by flow cytometry which showed that post-distillation leaf extract is pro-oxidant. Chlorogenic acid, kaempferol-3-glucoside and quercetin were found in the fresh leaves’ extracts, according to HPLC-DAD. PLC-DAD permitted the isolation of p-coumaric acid, E-3-(4-(((E)-3-(3,4-dihydroxyphenyl) acryloyl) oxy)-3-hydroxyphenyl) acrylic acid and a diglucosylated derivative of ursolic acid, which were analyzed by ¹H and ¹³C NMR. Our results suggest that the fresh leaf extract of Steiractinia aspera Cuatrec has potential use for antioxidant applications.