The mechanism of encapsulating curcumin into oleosomes (Lipid Droplets)

Organisms have evolved intracellular micron-sized lipid droplets to carry and protect lipids and hydrophobic minor compounds in the hydrophilic environment of cells. These droplets can be utilized as carriers of hydrophobic therapeutics by taking advantage of their biological functions. Here, we focus on the potential of plant-derived lipid droplets, known as oleosomes, as carriers for hydrophobic therapeutics, such as curcumin. By spectroscopy and confocal microscopy, we demonstrate that the oleosome membrane is permeable to hydrophobic curcumin molecules. Fluorescence recovery after photobleaching shows rapid curcumin diffusion towards oleosomes, with a diffusion time in the range of seconds. Following this, quenching probes and dilatational rheology reveal that part of the loaded curcumin molecules can accumulate at the oleosome interface, and the rest settle in the inner core. Our findings shed light on the loading mechanism of the plant-derived lipid droplets and underscore the significance of molecular localization for understanding the mechanism. This work not only enhances the understanding of the loading process but also shows potential for oleosomes use as lipid carriers.

A new series of acylhydrazones derived from metribuzin with modulated herbicidal activity

This paper reports the preparation and herbicidal evaluation of a small library of acylhydrazones based on the synthetic herbicide metribuzin. The hydrazone linkage easily obtained by reaction of metribuzin with aliphatic and aromatic aldehydes, masks efficiently the exocyclic amino group, thereby altering significantly H-bonding with the receptor and increasing the lipophilicity relative to the parent herbicide. The structures of all compounds, including key stereochemical issues on conformation and E/Z configuration around the C[bond, double bond]N bond were thoroughly elucidated by spectroscopic methods, and unambiguously corroborated by X-ray diffraction analysis. The herbicidal assays using an aliphatic and an aromatic acylhydrazone were performed on tomato and rapeseed plants grown in greenhouse. Our results demonstrate, regardless of rate application, that such acylhydrazone formulations do not alter the selectivity of metribuzin. Moreover, the herbicide activity was even higher in the alkyl derivative than that achieved by commercial metribuzin, thus suggesting that this substance can be applied with no need of combination with chemical coadjuvants, unlike most formulations of commercially available herbicides. Therefore, the study shows the promising effect of chemical derivatization of a common herbicide as metribuzin, to improve the herbicide activity without compromising selectivity, and allowing the farmers its use in crop protection safely and effectively.

The emulsifying ability of oleosomes and their interfacial molecules

Oleosomes are natural oil droplets, present in all organisms and abundant in oilseeds. After their aqueous extraction from oilseeds, they can be directly utilized as oil droplets in food, cosmetics and all types of oil-in-water emulsion systems. However, to expand the potential uses of oleosomes as green ingredients and to valorize oilseeds as efficient as possible, we explored their emulsifying ability. Oleosomes were extracted from rapeseeds, and 10.0 wt% oil-in-water emulsions were created after homogenization with 0.5-6.0 wt% oleosomes, and the droplet size of the emulsions and their structure was measured by laser diffraction and confocal laser scanning microscopy (CLSM), respectively. The emulsion with an oleosome concentration lower than 1.0 wt% gave unstable emulsions with visible free oil. At oleosome concentrations at 1.5 wt% or higher, we obtained stable emulsions with droplet sizes between 2.0 and 12.0 µm. To investigate the role of the oleosome interfacial molecules in stabilizing emulsions we also studied their emulsifying and interfacial properties (using drop tensiometry) after isolating them from the oleosome structure. Both oleosomes and their isolated interfacial molecules exhibited a similar behavior on the oil-water interfaces, forming predominantly elastic interfacial films, and also showed a similar emulsifying ability. Our results show that oleosomes are not stabilizing the oil-in-water emulsions as intact particles, but they provide their interfacial molecules, which are enough to stabilize an oil-water surface up to about 2 times bigger than the initial oleosome surface. The understanding of the behavior of oleosomes as emulsifiers, opens many possibilities to use oleosomes as alternative to synthetic emulsifiers in food and pharma applications.

A new method for the treatment of kitchen waste: Converting it into agronomic sprayable mulch film

This report describes a new method for converting kitchen waste (KW) with high water content into mulch films that can be applied in agricultural production. Specifically, the KW was emulsion polymerized with acrylic monomers (in various proportions) to obtain a series of sprayable bio-based KW-acrylate mulch films. The films' properties and performances were evaluated, and the experimental results showed that the KW-acrylate mulch films exhibited excellent sprayability, membrane formation, and mechanical properties, which allowed them to effectively reduce soil water evaporation (by 13-50%) and increase soil temperature (by 1.9-6.7%). Compared with bare soil, the soil treated with the optimized KW-acrylate mulch film increased the germination rate of rapeseeds by 20% and the yield of Chenopodium album by 0.7 times; the mulch film biodegradation then reached 70% after 100 days.

Evaluation of confirmatory data following the Article 12 MRL review and modification of the existing maximum residue levels for prothioconazole in celeriacs and rapeseeds

In accordance with Article 6 of Regulation (EC) No 396/2005, the applicants Bayer SAS Crop Science and the Agriculture and Horticulture Development Board submitted two requests to the competent national authority in the United Kingdom to modify the existing maximum residue levels (MRLs) for prothioconazole in rapeseeds and celeriacs, respectively. The data submitted in support of the requests were found to be sufficient to derive MRL proposals for these crops. The applicant Bayer SAS Crop Science additionally submitted a request to the competent national authority in the United Kingdom to evaluate the confirmatory data identified in the framework of the MRL review under Article 12 of Regulation (EC) No 396/2005 as not available. To address the data gaps, residue trials on carrots, onions, rapeseeds and wheat, and storage stability studies were submitted. The data gaps are considered fully addressed for the root and tuber vegetables, the oilseeds concerned and wheat. The data gaps have been partially addressed for onions, shallots, flowering brassica, Brussels sprouts, head cabbages, leeks, rye, barely and oat. The data gaps were not addressed for pulses and grass. Based on the risk assessment results, EFSA concluded that the short-term and long-term intake of residues resulting from the existing and intended uses of prothioconazole according to the reported agricultural practices is unlikely to present a risk to consumer health. For the triazole derivative metabolites (TDMs), only an indicative exposure assessment was performed considering celeriacs and rapeseeds; the results showed that the expected exposure to TDMs in these commodities is well below the toxicological reference values derived for the TDMs.