Conversion of Oleic Acid into Azelaic and Pelargonic Acid by a Chemo-Enzymatic Route

Oleic acid reduces oxidative stress in rat brain induced by some anticancer drugs

Oleic acid (OA) is a monounsaturated compound with many health-benefitting properties such as obesity prevention, increased insulin sensitivity, antihypertensive and immune-boosting properties, etc. The aim of this study was to analyze the effect of oleic acid (OA) and some anticancer drugs against oxidative damage induced by nitropropionic acid (NPA) in rat brain. Six groups of Wistar rats were treated as follows: Group 1, (control); group 2, OA; group 3, NPA + OA; group 4, cyclophosphamide (CPP) + OA; group 5, daunorubicin (DRB) + OA; and group 6, dexrazoxane (DXZ) + OA. All compounds were administered intraperitoneally route, every 24 h for 5 days. Their brains were extracted to measure lipoperoxidation (TBARS), H2O2, Ca+2, Mg+2 ATPase activity, glutathione (GSH) and dopamine. Glucose, hemoglobin and triglycerides were measured in blood. In cortex GSH increased in all groups, except in group 2, the group 4 showed the highest increase of this biomarker. TBARS decrease, and dopamine increase in all regions of groups 4, 5 and 6. H2O2 increased only in cerebellum/medulla oblongata of group 5 and 6. ATPase expression decreased in striatum of group 4. Glucose increased in group 6, and hemoglobin increased in groups 4 and 5. These results suggest that the increase of dopamine and the antioxidant effect of oleic acid administration during treatment with oncologic agents could result in less brain injury.

Azelaic acid can efficiently compete for the auxin binding site TIR1, altering auxin polar transport, gravitropic response, and root growth and architecture in Arabidopsisthaliana roots

The present study investigates the phytotoxic potential of azelaic acid (AZA) on Arabidopsis thaliana roots. Effects on root morphology, anatomy, auxin content and transport, gravitropic response and molecular docking were analysed. AZA inhibited root growth, stimulated lateral and adventitious roots, and altered the root apical meristem by reducing meristem cell number, length and width. The treatment also slowed down the roots' gravitropic response, likely due to a reduction in statoliths, starch-rich organelles involved in gravity perception. In addition, auxin content, transport and distribution, together with PIN proteins' expression and localisation were altered after AZA treatment, inducing a reduction in auxin transport and its distribution into the meristematic zone. Computational simulations showed that AZA has a high affinity for the auxin receptor TIR1, competing with auxin for the binding site. The AZA binding with TIR1 could interfere with the normal functioning of the TIR1/AFB complex, disrupting the ubiquitin E3 ligase complex and leading to alterations in the response of the plant, which could perceive AZA as an exogenous auxin. Our results suggest that AZA mode of action could involve the modulation of auxin-related processes in Arabidopsis roots. Understanding such mechanisms could lead to find environmentally friendly alternatives to synthetic herbicides.

Forensic analytical aspects of homemade explosives containing grocery powders and hydrogen peroxide

Homemade explosives become a significant challenge for forensic scientists and investigators. In addition to well-known materials such as acetone peroxide trimer, black powder, or lead azides, perpetrators often produce more exotic and less recognized Homemade Explosives (HMEs). Mixtures of hydrogen peroxide with liquid fuels are widely acknowledged as powerful explosives. Interestingly, similar explosive properties are found in mixtures of numerous solid materials with H2O2. Notably, powdered groceries, such as coffee, tea, grounded spices, and flour, are particularly interesting to pyrotechnics enthusiasts due to their easy production using accessible precursors, which do not attract the attention of security agencies. H2O2-based HMEs may become a dangerous component of improvised explosive devices for terrorists and ordinary offenders. For the four most powerful mixtures-HMEs based on coffee, tea, paprika, and turmeric-molecular markers useful for identification using the GC-MS technique have been proposed. Furthermore, the observed time-dependent changes in mixtures of H2O2 with these food products were studied and evaluated as a potential method for assessing the age of the evidence and reconstructing timelines of crimes. The paper also discusses the usefulness of FT-IR spectroscopy for identifying H2O2-based HMEs.

Selective Supercritical CO2 Extraction and Biocatalytic Valorization of Cucurbita pepo L. Industrial Residuals

The valorization of biomass residuals constitutes a key aspect of circular economy and thus a major challenge for the scientific community. Among industrial wastes, plant residuals could represent an attractive source of bioactive compounds. In this context, a residue from the industrial extraction of Cucurbita pepo L. seeds, whose oil is commercialized for the treatment of genito-urinary tract pathologies, has been selected. Supercritical CO₂ technology has been employed as a highly selective "green" methodology allowing the recovery of compounds without chemical degradation and limited operational costs. Free fatty acids have been collected in mild conditions while an enrichment in sterols has been selectively obtained from sc-CO₂ extracts by appropriate modulation of process parameters (supercritical fluid pressure and temperature), hence demonstrating the feasibility of the technique to target added-value compounds in a selective way. Obtained fatty acids were thus converted into the corresponding ethanol carboxamide derivatives by lipase-mediated biocatalyzed reactions, while the hydroxylated derivatives of unsaturated fatty acids were obtained by stereoselective hydration reaction under reductive conditions in the presence of a selected FADH₂-dependent oleate hydratase.

Spongy titanosilicate promotes the catalytic performance and reusability of WO3 in oxidative cleavage of methyl oleate

A tungsten containing catalyst catalyzed oxidative cleavage of methyl oleate (MO) by employing H₂O₂ as an oxidant and is known as an efficient approach for preparing high value-added chemicals, however, the tungsten leaching problem remains unresolved. In this work, a binary catalyst consisting of tungsten oxide (WO₃) and spongy titanosilicate (STS) zeolite is proposed for MO oxidative cleavage. The function of STS in this catalyst is investigated. On the one hand, STS converts MO to 9,10-epoxystearate (MES), which further forms nonyl aldehyde (NA) and methyl azelaaldehydate (MAA) with the catalysis of WO₃. In this way, MO oxidation and hydrolysis that generates unwanted diol product 9,10-dihydroxystearate (MDS) decreases obviously. On the other hand, STS decomposes peroxide and promotes the conversion of soluble peroxotungstate to insoluble polytungstate. Meanwhile, these tungsten species are allowed to precipitate on its surface instead of remaining in the liquid phase owing to its relative large specific area. Therefore, tungsten leaching can be reduced from 37.0% to 1.2%. Due to the cooperation of WO₃ and STS, 94.4% MO conversion and oxidative cleavage product selectivity of 63.1% are achieved, and the WO₃–STS binary catalyst maintains excellent catalytic performance for 8 recycling reactions.

Proposed “dissolve and precipitate” reaction mechanism of WO₃–STS catalyzed MO oxidative cleavage reaction.

Azelaic Acid: A Bio-Based Building Block for Biodegradable Polymers

Azelaic acid is a dicarboxylic acid containing nine C atoms, industrially obtained from oleic acid. Besides its important properties and pharmacological applications, as an individual compound, azelaic acid has proved to be a valuable bio-based monomer for the synthesis of biodegradable and sustainable polymers, plasticizers and lubricants. This review discusses the studies and the state of the art in the field of the production of azelaic acid from oleic acid, the chemical and enzymatic synthesis of bio-based oligo and polyester and their properties, including biodegradability and biocompostability.

Identification and quantification of dicarboxylic fatty acids in head tissue of farmed Nile tilapia (Oreochromis niloticus)

Nile tilapia (Oreochromis niloticus) was grown in Bangladesh with four different feeding treatments as part of a project that aims to produce fish in a cost-effective way for low-income consumers in developing countries. Fillet and head tissue was analysed because both tissues were destined for human consumption. Gas chromatography with mass spectrometry (GC/MS) analyses of transesterified fatty acid methyl ester extracts indicated the presence of ~ 50 fatty acids. Major fatty acids in fillet and head tissue were palmitic acid and oleic acid. Both linoleic acid and polyunsaturated fatty acids with three or more double bonds were presented in quantities > 10% of total fatty acids in fillet, but lower in head tissue. Erucic acid levels were below the newly proposed tolerable daily intake in the European Union, based on the consumption of 200 g fillet per day. Moreover, further analysis produced evidence for the presence of the dicarboxylic fatty acid azelaic acid (nonanedioic acid, Di9:0) in head tissue. To verify this uncommon finding, countercurrent chromatography was used to isolate Di9:0 and other dicarboxylic acids from a technical standard followed by its quantification. Di9:0 contributed to 0.4–1.3% of the fatty acid profile in head tissue, but was not detected in fillet. Fish fed with increasing quantities of flaxseed indicated that linoleic acid was the likely precursor of Di9:0 in the head tissue samples.

Cosmeceutical Aptitudes of Azelaic Acid

BACKGROUND

Azelaic acid (AZA) is a white crystalline dicarboxylic acid naturally found in grains, rye and barley. AZA has substantial biological and therapeutic abilities (viz a viz) its anti-inflammatory, anti-oxidant, anti-keratinizing, anti-microbial properties, etc. which contribute to its applicability in the management of mild to harsh dermatological complications (acne, rosacea, dermatitis, hyper-pigmentation, carcinomas, etc.). AZA has shown its effectiveness against varied non-inflammatory and inflammatory lesions by normalizing the hyper-keratinization statie and attenuating the increased levels of microbial content. Topically AZA, either alone or in conjunction with other active moieties, has proved to be effective in preventing acne and several other hyper-pigmentary conditions.

OBJECTIVES

Chronic applicability of AZA has been evidenced with the effects like itching, burning, stinging, redness, etc. To deal with the former issues, research is being conducted to substitute the conventional formulations with novel preparations (liposome's, niosomes, micro sponges, lipid nanocarriers, etc.), which could enhance the overall pharmaceutical and pharmacological profile of the drug.

CONCLUSION

This article is an attempt to highlight the basic physiochemical properties of AZA, its physiological role (especially in dermatology), various commercial preparations and recent novel approaches that are in research with an aim to augment the therapeutic and safety profile of AZA.

Homogeneous Catalysis and Heterogeneous Recycling: A Simple Zn(II) Catalyst for Green Fatty Acid Esterification

This work describes the use of simple zinc(II) salts (ZnCl₂, ZnCO₃, Zn(OAc)₂, ZnO, Zn(ClO₄)₂, Zn(TfO)₂, and Zn(BF₄)₂) as effective catalysts for the esterification of fatty acids with long-chain alcohols and simple polyols through a homogeneous system that allows the gradual and selective removal of water. The results show that the catalytic activity depends on the nature of the counterion: the most effective are the salts with poorly coordinating anions (perchlorate and triflate) or containing basic Brønsted anions (oxide, acetate, and carbonate). However, only with the latter is it possible to fully recover the catalyst at the end of each run, which is easily filtered in the form of zinc carboxylate, given its insolubility in the ester produced. In this way, it is possible to recycle the catalyst numerous times, without any loss of activity. This beneficial prerogative couples the efficiency of the homogeneous catalysis with the advantage of the heterogeneous catalysis. The process is, therefore, truly sustainable, given its high efficiency, low energy consumption, ease of purification, and the absence of auxiliary substances and byproducts.

Oleaginous Yeasts as Cell Factories for the Sustainable Production of Microbial Lipids by the Valorization of Agri-Food Wastes

The agri-food industry annually produces huge amounts of crops residues and wastes, the suitable management of these products is important to increase the sustainability of agro-industrial production by optimizing the entire value chain. This is also in line with the driving principles of the circular economy, according to which residues can become feedstocks for novel processes. Oleaginous yeasts represent a versatile tool to produce biobased chemicals and intermediates. They are flexible microbial factories able to grow on different side-stream carbon sources such as those deriving from agri-food wastes, and this characteristic makes them excellent candidates for integrated biorefinery processes through the production of microbial lipids, known as single cell oils (SCOs), for different applications. This review aims to present an extensive overview of research progress on the production and use of oleaginous yeasts and present discussions on the current bottlenecks and perspectives of their exploitation in different sectors, such as foods, biofuels and fine chemicals.

Electrochemical behaviour of piperine. Comparison with control antioxidants

Piperine, as the most abundant alkaloid in pepper, gained a lot of attention for possible antioxidant and therapeutic properties. Electrochemical techniques were applied to widely evaluate the redox behavior of piperine by comparison to that of well-known antioxidants: ascorbic acid, protocatechuic acid, syringic acid, tyrosine and capsaicin used as controls. Also, electrochemistry was involved in an innovative way to investigate the potential antioxidant properties of piperine combined with different in vitro peroxidation and reducing assays: (i) 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH) scavenging; (ii) 2,2,6,6-tetramethylpiperidinyl-1-oxy (TEMPO) scavenging; (iii) ferric ions (Fe³⁺) reducing power; (iv) hydrogen peroxide (H₂O₂) scavenging. Results show that piperine readily reacts with highly oxidizing radicals and bind redox-active metal ions in a similar manner as antioxidants used as model.

Chemical Penetration Enhancers Increase Hydrogen Peroxide Uptake in C. elegans for In Vivo Fast Photochemical Oxidation of Proteins

Fast photochemical oxidation of proteins (FPOP) is a hydroxyl radical protein footprinting method that covalently labels solvent-accessible amino acids by photolysis of hydrogen peroxide. Recently, we expanded the use of FPOP for in vivo (IV-FPOP) covalent labeling in C. elegans. In initial IV-FPOP studies, 545 proteins were oxidatively modified in all body systems within the worm. Here, with the use of chemical penetration enhancers (CPEs), we increased the number of modified proteins as well as the number of modifications per protein to gain more structural information. CPEs aid in the delivery of hydrogen peroxide inside C. elegans by disturbing the highly ordered lipid bilayer of the worm cuticle without affecting worm viability. IV-FPOP experiments performed using the CPE azone showed an increase in oxidatively modified proteins and peptides. This increase correlated with greater hydrogen peroxide uptake by C. elegans quantified using a chemical fluorophore demonstrating the efficacy of using CPEs with IV-FPOP. Mass spectrometry proteomics data are available via ProteomeXchange with identifier PXD019290.