A small and focused library of steroidal non-fused and fused pyrimidines was prepared from pregnenolone acetate and diosgenin, respectively. The key step was the cycloaddition reaction of nitrogen-containing 1,3-binucleophiles with the steroidal α,β-unsaturated ketone. Urea, thiourea and guanidine reacted in a similar manner and afforded the steroidal pyrimidines in good yields. The antiproliferative tests against human tumor cell lines gave GI₅₀ values in the micromolar range and had no effect on healthy fibroblasts. Additional experiments indicated that the compounds did not act as P-glycoprotein substrates, thus avoiding the rise of drug resistance. The fused steroidal pyrimidinethione was selected as drug lead for further testing due to its strong antiproliferative activities within the low micromolar range.

The genus Pycnoporus includes fungi with great potential for the production of antibiotic substances. It is necessary to develop new models to assess their effectiveness against microorganisms with an economic impact, such as phytopathogenic fungi. The objective of this study is to evaluate three models of Pycnoporus sanguineus for the growth inhibition of the phytopathogens Botrytis cinerea and Fusarium oxysporum. Model 1 involves dual tests of the antagonistic activity of P. sanguineus vs. phytopathogens, Model 2 involves antifungal effectiveness tests of cinnabarin, and Model 3 involves antifungal effectiveness tests of P. sanguineus extract. Models 2 and 3 are contrasted with products containing benomyl and captan. The results show that Model 3 is the most effective in controlling B. cinerea, with an inhibition percentage of 74.34% (p < 0.05) and a decrease in the growth rate (3.85 mm/day; p < 0.05); the same is true for F. oxysporum, with an inhibition percentage of 47.14% (p < 0.05). In general, F. oxysporum exhibits greater resistance (p < 0.05). The results of this study indicate that P. sanguineus extracts may be used as control agents for fungal species in the same way as other Pycnoporus species. Although commercial products are very efficient at inhibiting phytopathogens, one must consider the disadvantages of their use. In the short term, new models involving Pycnoporus for biological control in food production will be developed.

This work presents the green synthesis of iron oxide nanoparticles (IONPs) using Baccharis salicifolia extract and their incorporation in mesoporous silica MCM-41, obtaining an MCM-41@IONP composite. The MCM-41@IONP composite was characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), nitrogen adsorption and desorption, scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). The use of the natural reducing agent Baccharis salicifolia resulted in nanoparticles with an average size of 31 nm. Furthermore, we showcase the application of the MCM-41@IONP nanocomposite in a metal–insulator–semiconductor (MIS) diode, which was fabricated at room temperature. The current–voltage and capacitance–voltage curves of the MIS diode were carefully measured and subjected to detailed analysis. The results demonstrate the potential utility of MCM-41@IONP nanocomposite-based MIS diodes, suggesting their applicability in the design of biosensors or as discrete components in electronic devices.

Background. The use of agricultural waste is a key strategy to strengthen the sustainable production of edible and medicinal mushrooms, by allowing its valorization in the reduction of production costs. In agricultural regions such as the Altiplano Poblano, there is a wide availability of lignocellulosic waste with the potential to be used as alternative substrates. Objective. To evaluate the productive performance of the mushroom Hericium erinaceus (Bull.) Pers., using agricultural waste from the Altiplano Poblano as substrates for its cultivation. Methodology. Corn cobs and stubble, wheatgrass, pine sawdust, ocoxal (pine needle litter, Pinus spp.), and a balanced lignocellulosic mixture were used as substrates. The productive parameters mycelial colonization rate, biological efficiency, and production rate were evaluated in order to compare the mushroom's performance on each of the substrates tested. Results. Corn cobs and the control group showed the highest biological efficiency (64.72 y 63.58 %) and an average production rate of 11.32 and 12.64 g day⁻¹ respectively, which is attributed to their adequate porosity and carbon/nitrogen ratio. In contrast, corn stover and ocoxal showed low yields, while pine sawdust and wheatgrass registered the lowest productive performance. Implications. The results demonstrate the viability of using regional agricultural residues as alternative substrates, contributing to waste reduction, efficient use of local resources, and strengthening the circular economy in agricultural production systems. Conclusions. Of the agricultural residues, corn stover shows high potential for the cultivation of H. erinaceus, allowing for improved productive performance of the fungus and promoting sustainable production practices based on the valorization of agricultural byproducts.