Contaminant dynamics in honey bees and hive products of apiaries from environmentally contrasting Argentinean regions.

Argentina is a leading honey producer and honey bees are also critical for pollination services and wild plants. At the same time, it is a major crop producer with significant use of insecticides, posing risks to bees. Therefore, the presence of the highly toxic insecticide chlorpyrifos, and forbidden contaminants (organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs)) was investigated in honey bee, beebread, wax and honey samples in apiaries from three contrasting regions of Argentina. Chlorpyrifos was detected in all samples with higher levels during period 1 (spring) in contrast to period 2 (fall), agreeing with its season-wise use in different crops, reaching 3.05 ng/g in honey bees. A subsequent first-tier pesticide hazard analysis revealed that it was relevant to honey bee health, mainly due to the high concentrations found in wax samples from two sites, reaching 132.4 ng/g. In addition, wax was found to be the most contaminated matrix with a prevalence of OCPs (∑OCPs 58.23-172.99 ng/g). Beebread samples showed the highest concentrations and diversity of pesticide residues during period 1 (higher temperatures). A predominance of the endosulfan group was registered in most samples, consistent with its intensive past use, especially in Central Patagonia before its prohibition. Among the industrial compounds, lighter PCB congeners dominated, suggesting the importance of atmospheric transport. The spatio-temporal distribution of pesticides shows a congruence with the environmental characteristics of the areas where the fields are located (i.e., land use, type of productive activities and climatic conditions). Sustained monitoring of different pollutants in beekeeping matrices is recommended to characterize chemical risks, assess the health status of honey bee hives and the pollution levels of different agroecosystems. This knowledge will set a precedent for South America and be helpful for actions focused on the conservation of pollination services, apiculture and ecosystems in Argentina.

Galenic formulations of Cannabis sativa: comparison of the chemical properties of extracts obtained by simple protocols using lipidic vehicles.

The growing use of Cannabis sativa as a complementary therapy to allopathic medicine has brought about the modification of laws for its use worldwide. This entails the need to harmonize the methods of galenic preparations in pharmacies and cannabis-specialized non-governmental organizations as well as for self-provision as contemplated in some current legislation, such as that of Argentina. Thus, this work aimed to study simple and efficient methods to produce medicinal cannabis oils that require low-cost equipment and few handling steps. The final formulas allowed the obtaining of preparations of known concentrations of neutral cannabinoids, total polyphenol content, total flavonoid content, and antioxidant capacity. These methods allow for the selection of convenient vehicles and access to safe medicinal products of standardized quality. Our results show that cannabis extraction can be efficiently performed by directly using long-chain lipidic vehicles as extractants, resulting in a formulation with maximized oxidizing capacity and potentially extending its durability.

Occurrence of chlorpyrifos and organochlorine pesticides in a native bumblebee (Bombus pauloensis) living under different land uses in the southeastern Pampas, Argentina.

Pollinators such as Apidae bees are vital for ecosystems and food security. Unfortunately, their populations have declined due to several factors including pesticide use. Among them, the organophosphate insecticide chlorpyrifos, poses a global threat, while legacy compounds like organochlorine pesticides (OCPs) easily bioaccumulate, increasing the concern. Bombus pauloensis, a widely distributed native bee in Argentina, is used for commercial pollination; however, information regarding their health status is scarce. This study assessed chlorpyrifos and OCP levels in B. pauloensis (workers and males) and related environmental matrices living from three different land uses schemes, by means of GC-ECD and GC-MS. The ornamental horticulture field (OP) showed the highest total pesticide concentrations in workers (13.1 ng/g), flowers and soils, whereas the organic agriculture field (OA) exhibited the lowest. Chlorpyrifos was the most abundant compound, accounting for at least 20 % of pesticide load across all matrices. The food production horticulture field (FH) had the highest chlorpyrifos concentration in workers, males and soils (5.0, 4.4 and 3.3 ng/g, respectively), suggesting a local greater usage, whereas OA showed the lowest. Regarding OCPs groups, Drins and DDTs were predominant in most matrices, with FH males registering the highest levels (4.0 and 2.5 ng/g, respectively), closely followed by OP. However, metabolites' contribution indicated historical use and atmospheric inputs in all sites. Multivariate analyses confirmed the significance of site and bumblebee sex to explain pesticide composition. Males from all sites exhibited higher chlorpyrifos levels than workers and this trend was similar for some OCP groups. Overall, OA differed from FH and OP, indicating a correlation between production modes and pesticide profiles. This study demonstrates the value of B. pauloensis as a pesticide biomonitor but also offers insights into its populations' health in the area. In this sense, this information could be useful towards the preservation of this crucial pollinator.

Broad-Spectrum Antiviral Effect of Cannabidiol Against Enveloped and Nonenveloped Viruses.

Introduction: Cannabidiol (CBD), the main non-psychoactive cannabinoid of the Cannabis sativa plant, is a powerful antioxidant compound that in recent years has increased interest due to causes effects in a wide range of biological functions. Zika virus (ZIKV) is a virus transmitted mainly by the Aedes aegypti mosquitoes, which causes neurological diseases, such as microcephaly and Guillain-Barre syndrome. Although the frequency of viral outbreaks has increased recently, no vaccinations or particular chemotherapeutic treatments are available for ZIKV infection. Objectives: The major aim of this study was to explore the in vitro antiviral activity of CBD against ZIKV, expanding also to other dissimilar viruses. Materials and Methods: Cell cultures were infected with enveloped and nonenveloped viruses and treated with non-cytotoxic concentrations of CBD and then, viral titers were determined. Additionally, the mechanism of action of the compound during ZIKV in vitro infections was studied. To study the possible immunomodulatory role of CBD, infected and uninfected Huh-7 cells were exposed to 10 µM CBD during 48 h and levels of interleukins 6 and 8 and interferon-beta (IFN-ß) expression levels were measured. On the other hand, the effect of CBD on cellular membranes was studied. For this, an immunofluorescence assay was performed, in which cell membranes were labeled with wheat germ agglutinin. Finally, intracellular cholesterol levels were measured. Results: CBD exhibited a potent antiviral activity against all the tested viruses in different cell lines with half maximal effective concentration values (CE50) ranging from 0.87 to 8.55 µM. Regarding the immunomodulatory effect of CBD during ZIKV in vitro infections, CBD-treated cells exhibited significantly IFN-ß increased levels, meanwhile, interleukins 6 and 8 were not induced. Furthermore, it was determined that CBD affects cellular membranes due to the higher fluorescence intensity that was observed in CBD-treated cells and lowers intracellular cholesterol levels, thus affecting the multiplication of ZIKV and other viruses. Conclusions: It was demonstrated that CBD inhibits structurally dissimilar viruses, suggesting that this phytochemical has broad-spectrum antiviral effect, representing a valuable alternative in emergency situations during viral outbreaks, like the one caused by severe acute respiratory syndrome coronavirus 2 in 2020.

Stable and Reusable Fe3 O4 /ZIF-8 Composite for Encapsulation of FDH Enzyme under Mild Conditions Applicable to CO2 Reduction.

The enzymatic reduction of carbon dioxide presents limited applicability due to denaturation and the impossibility of biocatalyst recovery; disadvantages that can be minimized by its immobilization. Here, a recyclable bio-composed system was constructed by in-situ encapsulation under mild conditions using formate dehydrogenase in a ZIF-8 metalorganic framework (MOF) in the presence of magnetite. The partial dissolution of ZIF-8 in the enzyme's operation medium can be relatively inhibited if the concentration of magnetic support used exceeds 10 mg mL-1 . The bio-friendly environment for immobilization does not harm the integrity of the biocatalyst, and the production of formic acid is improved 3.4-fold compared to the free enzyme because the MOFs act as concentrators of the enzymatic cofactor. Furthermore, the bio-composed system retains 86 % of its activity after a long time of five cycles, thus indicating an excellent magnetic recovery and a good reusability.

Chemical profiles of cannabis sativa medicinal oil using different extraction and concentration methods.

The present study shows the variability in chemical profiles of three different varieties of Cannabis sativa extracts used in medicinal cannabis oil when using two different extraction and evaporation methods. Procedures were compared by analyzing rate of total terpenoids to the principal cannabinoids, tetrahydrocannabinol (THC) and cannabidiol (CBD), using gas chromatography coupled to mass spectrometry (GC-MS). The extraction of inflorescences using soxhlet method showed the highest mass of final extract. Also, the use of heating and the presence of oxygen when evaporating the solvents, greatly modified the final profiles due to evaporation or chemical reactions. These variations in chemical profiles must be carefully taken into account and standardized in the elaboration of medicinal oils.

Experimental and theoretical studies on the enantioselectivity of molecularly imprinted polymers prepared with a chiral functional monomer.

A comprehensive study on the enantioseparation of racemic bis[1-phenylethyl]amine (PEA) on a series of molecularly imprinted polymers (MIPs) prepared using the chiral functional monomer (S)-2-(2-methyl-acryloylamino)-3-phenyl propionic acid (MAPP) is reported. MIP-R, MIP-S and MIP-RS, were synthesized separately by imprinting the pure enantiomers (R-, S-PEA) and racemic PEA, respectively, MAPP, EDGMA as crosslinker and chloroform as the porogen. It was found that all MIPs prepared were able to resolve the PEA racemate. Residence times (t(r)) and enantioselectivity factors (α) were estimated from typical elution chromatography experiments. Frontal chromatography experiments were conducted to acquire the adsorption isotherms for both enantiomers on the different MIPs (and on the non-imprinted polymer, NIP). The adsorption isotherms were analyzed using the affinity spectrum (AS) and the expectation-maximization (EM) methods. The study also involved the theoretical evaluation of the MAPP/enantiomers interactions in the pre-polymer mixture. The EM method predicts mono- and bimodal distribution of affinity binding sites depending upon the polymer analyzed. Apparently, the enantioseparation process depends on relatively small differences in the stabilization of the diasteroisomeric ion-pairs PEA/MAPP complexes on the surface of the polymers.

Role of ruthenium oxidation states in ligand-to-ligand charge transfer processes.

We describe in this paper the properties of [Ru(II/III)(bpy)(2)ClL](+1/+2) and [Ru(II/III)(bpy)(2)L(2)](+2/+3). L = ditolyl-3-pyridylamine (dt3pya) is a redox active ligand related to triarylamines, which is very similar to 3-aminopyridine except for the reversible redox behavior. The monosubstituted complex shows a metal-to-ligand charge-transfer (MLCT) at 502 nm, and reversible waves in acetonitrile at E(0)(Ru(III/II)) = 1.07 V, E(0)(L(+/0)) = 1.46 V (NHE). The disubstituted complex shows an MLCT at 461 nm, a photorelease of dt3pya with quantum yield of 0.11 at 473 nm, and two reversible one-electron overlapped waves at 1.39 V associated with one of the ligands (1.37 V) and Ru(III/II) (1.41 V). Further oxidation of the second ligand at 1.80 V forms a 2,2'-bipiridine derivative, in an irreversible reaction similar to dimerization of triphenylamine to yield tetraphenylbenzidine. In the dioxidized state, the spectroelectrochemistry of the disubstituted complex shows a ligand-to-ligand charge transfer at 1425 nm, with a transition moment of 1.25 Å and an effective two-state coupling of 1200 cm(-1). No charge transfer between ligands was observed when Ru was in a 2+ oxidation state. We propose that a superexchange process would be involved in ligand-metal-ligand charge transfer, when ligands and metals are engaged in complementary π interactions, as in metal-ligand-metal complexes. Best orbital matching occurs when metallic donor fragments are combined with acceptor ligands and vice versa. In our case, Ru(III) bridge (an acceptor) and two dt3pya (donors, one of them being oxidized) made the complex a Robin-Day Class II system, while the Ru(II) bridge (a donor, reduced) was not able to couple two dt3pya (also donors, one oxidized).

Charge transfer properties of Tröger base derivatives.

Two triarylamine centers bridged through an aliphatic bridge feature unexpected charge transfer properties, bearing an important electronic coupling between them in the absence of a π linker; EPR, electrochemistry, electronic spectroscopy and first principles molecular calculations are combined to study the electronic structure of this compound.