Francisco Javier Espinosa-García

En Persea americana se han identificado alrededor de 362 metabolitos secundarios (MS) con actividad antialimentaria, insecticida y fungicida, entre otras. El conocimiento de su presencia y diversidad en el aguacate es de suma importancia ya que estos compuestos son esenciales para la sustentabilidad del cultivo. Por lo tanto, a través del análisis fitoquímico, hecho mediante cromatografía de gases, fueron identificados un total de 74 MS en 15 genotipos de aguacate tipo Hass; 32 en hoja y 42 en flor. Los resultados obtenidos de este estudio contribuyen significativamente al conocimiento sobre el perfil químico del aguacate y, la presencia de estos compuestos en distintos órganos.

Arbuscular mycorrhizal (AM) fungi enhance plant flowering and fruiting by improving nutrient and water uptake. The aim of this study was to evaluate how AM fungal colonization percentage and edaphic factors, modulate flowering and fruiting in secondary vegetation (SV) species with different biological traits, in a temperate forest. We conducted the research in four sites at two elevation intervals in a temperate forest in Mexico, focusing on three SV species. We recorded flower, fruit and AM fungal colonization percentages during the rainy and the dry season. Soil was collected from the rhizosphere of each SV species to determine organic matter (OM), pH, relative soil moisture (RSM), available phosphorus (Ava-P) and nitrogen (Ava-N). The AM fungal colonization, flower and fruit percentages showed interspecific and temporal variations. Structural equation models showed that flowering was positively influenced by RSM in Acaena elongata and negatively influenced by AN in Solanum pubigerum. Fruiting was positively influenced by AM fungal colonization and negatively by AP in A. elongata, with a relevant indirect effect of OM. In S. pubigerum, the effect of AM fungal colonization was slightly positive, while AN and pH had a greater effect on fruiting. While in Ageratina glabrata the effect of AM fungal colonization on fructification was not evident. The study highlights the critical role of AM fungal colonization and soil properties such as OM, pH and N in flower and fruit production, which depend on the biological traits of the host plant species.

Mexico is home to a rich variety of fermented beverages made from both wild and domesticated plant species. Fermentation practices vary, with producers using either wild or inoculated techniques to obtain culturally valued final products. It is generally assumed that wild fermentations yield a greater diversity of volatile compounds compared to inoculated fermentations, as the latter tend to reduce microbial diversity throughout the process. However, this pattern remains largely unexplored in relation to the volatile profiles of traditionally fermented cactus-based beverages. Despite this assumption, comparative studies examining these profiles across different fermentation methods are scarce, especially given that these beverages are not produced under standardized conditions. To investigate this, we used GC-MS to characterize the aroma profile of colonche, a traditional fermented beverage made primarily from Opuntia streptacantha fruits. Colonche is produced by both wild and inoculated fermentation methods. In addition, a rapid sensory evaluation using the modified Flash Profile (mFP) technique was performed to evaluate flavor differences between the fermentation methods. A total of 55 volatile compounds were identified, with wild fermentations showing greater diversity (55) than inoculated fermentations (50). Most compounds overlapped, but five were unique to spontaneous fermentations, contributing to distinct sensory profiles. The mFP results also indicate that sensory attributes vary by fermentation type, with wild fermentations being more strongly associated with positive descriptors such as taste and smell, while inoculated samples have a distinctly pungent aftertaste. These findings highlight colonche not only as a reservoir of microbial diversity in arid regions but also as a culturally significant beverage with complex sensory attributes. Recognizing and preserving these attributes is essential for safeguarding traditional foodscapes.

In order to contribute to the fight against the antibiotic resistance crisis, we used a dual‐activity prospection strategy for natural product mixtures with antibiotic resistance modulating and antibacterial activities in the essential oils (EOs) of Artemisia ludoviciana, Lippia graveolens, and Cosmos bipinnatus against multidrug‐resistant strains of Pseudomonas aeruginosa HIM‐MR01, Staphylococcus aureus HIM‐MR02, Enterococcus faecalis HIM‐MR05, and Salmonella typhi HIM‐MR06. The three EOs exerted antibacterial activity on the bacterial strains with minimum inhibitory concentrations (MICs) ranging from 0.1735 to 65.6263 µg/mL. When combined with antibiotics, the L. graveolens EO showed the highest resistance modulation for vancomycin (VA), nalidixic acid (NA), and chloramphenicol against S. aureus (MIC: 0.0347 µg/mL), E. faecalis (MIC: 0.0832 µg/mL), and P. aeruginosa (MIC: 0.0694 µg/mL). For the A. ludoviciana EO, resistance modulation was based on S. aureus‐VA (MIC: 0.6525 µg/mL) and E. faecalis‐NA (MIC: 0.3262 µg/mL). Thereby, C. bipinnatus EO did not show significant antibiotic resistance modulating activity. In conclusion, L. graveolens and A. ludoviciana EOs showed antibacterial activity and the greatest potential in inhibiting bacterial resistance to antibiotics. The dual activity of these EOs makes them a promising adjuvant in the treatment of diseases caused by multidrug‐resistant pathogenic bacteria.

Volatile organic compounds (VOCs) play an important role in plant survival and adaptation. They contribute to defense against pests and pathogens, tolerance to abiotic stress, and the mediation of essential ecological interactions such as pollination and attraction of dispersal agents. The complex mixture of VOCs produced by an organism, known as volatilome, varies across species, populations, and individuals, making VOCs a major factor in crop diversification and adaptation. In this context, characterizing the volatilome of crop genotypes can provide insight into their ecological associations and potential relationships with agronomic traits. In this study, the volatilome of 15 closely related ‘Hass’-type avocado variant genotypes was analyzed using gas chromatography–mass spectrometry (GC–MS). These genotypes had been previously characterized by agromorphological attributes such as early bearing, dwarf growth habit, and/or high productivity according to IPGRI descriptors. A total of 65 volatile compounds were identified, 18 of which—four in leaves and 14 in flowers—had not been previously reported in Persea americana. Chemical profiling allowed classification of the genotypes into eight foliar and floral chemotypes. Most dwarf genotypes, except for F4A7, exhibited distinct chemical profiles compared to the ‘Hass’ cultivar and the other variants. Correlation analyses indicated that certain compounds, including phytol (r = 0.6112) and decane (r = 0.6822), were positively associated with yield. Phytol, 2-[(8z,11z)-heptadeca-8,11-dienyl]furan, tricosane, 2,4-dimethyl-1-heptene, and decane also showed moderate associations with fruit quality traits such as size and weight, with r values ranging from 0.6585 to 0.5799. In contrast, palmitic acid, β-caryophyllene, humulene, and α-farnesene exhibited negative correlations with yield, with an average r-value of –0.5960. Furthermore, the results indicated the presence of tissue-specific compounds, with 36 volatiles detected exclusively in the floral tissue of the analyzed genotypes. These findings advance our understanding of the avocado volatilome and suggest that volatilome profiles could be used as an additional selection criterion for identifying high-performing genotypes.

The relationship between arbuscular mycorrhizal fungi (AMF) and secondary vegetation (SV) species at early phenological stages is critical for the successful establishment of these plants on disturbance sites in temperate forests. The main objective of this research is to evaluate the effect of AMF colonization on the early phenological stages (germination and early growth) of three shrub species present in the SV of a temperate forest in central Mexico. We collected soil from different sites in theAbies religiosaforest in central Mexico. We collected seeds ofAcaena elongata,Ageratina glabrata, andSolanum pubigerum. We used a controlled experimental design with pasteurized soil (-AMF treatments) and unpasteurized soil (+ AMF treatments). We monitored germination percentage, growth (shoot and root weight and total biomass), AMF root colonization, and the mycorrhizal response index (MRI) for each plant species. All three species tested benefited by AMF, showing higher germination rates. Shoot and root weight and total biomass were significantly higher in the + AMF treatment.Solanum pubigerumshowed greater stem length andAgeratina glabratashowed greater root development due to AMF.Ageratina glabrataandAcaena elongatawere the most responsive to AMF as indicated by MRI. This research underscores the critical role of AMF in the early phenological stages of SV and highlights the potential ecological benefits of AMF in supporting plant germination and plant growth. These results suggest that AMF enhance germination and early growth of secondary vegetation species, which can be considered in management plans for forest ecosystems.

La producción de formas reactivas de N ha superado los límites planetarios que permiten el adecuado funcionamiento de los ecosistemas. Su depósito representa una amenaza tanto a la biodiversidad como a la salud pública. Los sistemas de monitoreo para cuantificar su depósito son escasos, por lo que el biomonitoreo puede ser una alternativa, donde se buscan variables fisiológicas que respondan a la disponibilidad de N, así como organismos con tolerancia a la alta disponibilidad de N. Aunque con frecuencia se usan como biomonitores organismos epífitos, muchos de ellos están restringidos a zonas muy húmedas y áreas de poca perturbación antrópica. El objetivo de esta revisión es identificar biomonitores potenciales de depósito de N para sitios perturbados. Las malezas ruderales son de los organismos que persisten y son abundantes en áreas urbanas, donde el disturbio, la emisión de contaminantes y las tasas de depósito de N suelen ser elevadas. Además, diversas malezas son identificadas como nitrófilas, y en pastos, un grupo bien representado entre las malezas, se ha documentado la tolerancia a altas tasas de depósito de N. El uso de este tipo de organismos ha permitido identificar el aporte de las fuentes de nitrógeno reactivo y el incremento de N en el ambiente en sitios restrictivos para otras plantas.

To evaluate the capacity of fourteen sesquiterpenes to enhance the action of known antibiotics against two β-lactam resistant strains, and to determine a possible mechanism of antibiotic sensitization by assessing their ability to inhibit a β-lactamase enzyme. The broth microdilution method was used to determine the minimum inhibitory concentration (MIC) of β-lactams cefuroxime (CEFM) and cefepime (CPM) against Staphylococcus aureus 23MR and Escherichia coli 82MR strains in the absence and presence of subinhibitory concentrations of fourteen natural sesquiterpenes. (1R,4R)-4H-1,2,3,4-tetrahydro-1-hydroxycadalen-15-oic acid (5), xerantolide (8), estafiatin (11), and ambrosin (12) exhibited the best sensitizing effects in both strains. These compounds were able to reduce the MIC of CEFM by 2-fold (from 15.0 to 7.5 µg/mL) and CPM by 15-fold (from 0.9 to 0.06 µg/mL) in S. aureus 23MR. For E. coli 82MR, the MIC of CEFM was reduced up to 8-fold (from 120.0 to 15.0 µg/mL). In this strain, the activity of 8 and 11 surpassed that of clavulanic acid (positive reference), which reduced the MIC of CEFM from 120.0 to 60.0 µg/mL. To elucidate a possible mechanism of antibiotic sensitization, molecular docking studies were conducted with β-lactamases. These studies revealed an affinity with the enzymes (energies > -4.93 kcal/mol) by the formation of hydrogen bonds with certain conserved amino acid residues within the active sites. However, the in vitro results indicated only marginal inhibition, with percentages less than 50%. The bioevaluations indicate that nine of fourteen sesquiterpenes enhance the action of CEFM and CPM against the β-lactam resistant strains, and these compounds displayed moderate activity as inhibitors of β-lactamase.

Background: The first monograph of the genus Viguiera was published in 1918 by Blake, including about 141 species. Schilling & Panero based on studies of molecular sequences of nuclear Internal Transcribed Spacer and External Transcribed Spacer, as well as cpDNA, proposed to reclassify the genus, relocating its species in at least other nine genera. Question: Is it possible to identify distinctive patterns between the species of the new classification of Viguiera s. l. and the results of the chemical studies reported? Species considered: Sixty-seven species within the wide Viguiera circumscription with chemical studies and biological activities reported. Results: The species of the genus Viguiera synthesize terpenoids represented mainly by sesquiterpene lactones and diterpenes, with triterpenes, polyacetylenes, volatile terpenoids and flavonoids also present. The main types of secondary metabolites were present in the studied species, although some compounds were more frequent than others in some clades. Conclusion: Germacrolides, heliangolides, furanoheliangolides, tetracyclic diterpenes and flavonoids are the main constituents of Viguiera and segregated genera. Some interesting chemotaxonomic relationships are noted. Nevertheless, nondistinctive clear patterns were observed between clades and chemical groups. These results may be a consequence of the reported chemical studies of the species of Viguiera s. l., which have not agreed on objetives or methodologies.