Explore the vast range of titles available.

A review of the investigations devoted to the solvent extraction processes of metal ions with a chelating ligand thenoyltrifluoroacetone (HTTA) is presented herein. It seems that this molecule has been preferred in the field for more than half a century, and that it is used very often as an extractant for almost all metals. The main objective of the present review is also to provide an overview of the synergistic solvent extraction of lanthanoids, particularly with the use of a β-diketone−neutral mixture. Based on the previous published results in the open literature, the extraction efficiency has been examined in detail and discussed further mainly in terms of the corresponding equilibrium constants among other outlined, so-important parameters. Major conclusions on the role of ligating groups of extractants towards the mechanism, an improved extraction enhancement, and selectivity are additionally provided. The fact that ionic liquids (ILs) appear to be replacing volatile diluents in the field of the liquid–liquid extraction of metals, again with the participation of this β-diketone, is not surprising. As is well known, a very efficient and simple way to determine the stoichiometry of the extracted species in the organic phase is by the simple use of the slope analysis method; however, it is sometimes difficult to perform, either because it somehow requests good solubility of the ligand or because obtained slopes are quite often far from integer values in ILs.

A survey of the experimental equilibrium constants in solution for the mixed complexes of 4f ions with acidic (chelating) and O-donor organophosphorus ligands published in the period between 1954 and 2022 is presented. These data are widely used in both analytical and solvent extraction chemistry. Important data evaluation criteria involved the specification of the essential reactions, process conditions and the correctness of techniques and calculations used, as well as appropriate equilibrium analysis of experimental data. Higher-quality data have been evaluated, compiled and presented herein, providing a synoptic view of the unifying theme in this area of research, i.e., synergism.

In this work, the mutual solubilities of sets of organic diluents (CHCl3, C6H6, C2H4Cl2, CCl4, C6H12, and n-hexane) with the organic compound ethylene glycol are investigated via gas chromatography (GC). The experimental data measured for these binary organic systems are used to adjust the future nonaqueous systems for the solvent extraction of various metals with ligands. The obtained results showed that the solubility of ethylene glycol decreased in the order CHCl3>C6H6>C2H4Cl2>CCl4(0%)≈C6H12≈n-hexane. On the other hand, the solubility of the tested traditional organic diluents in ethylene glycol decreased in the following order: C6H6>CHCl3>C2H4Cl2>n-hexane>C6H12>CCl4. 1H NMR was also used as an analytic method in order to compare the obtained results for the samples showing significant solubility only, including an additional study with 1,2- or 1,3-propanediol. The enhanced solubility of the C6H6 compound in ethylene glycol was identified here as critical due to the GC technique, which will be without future consequences in chemical technology. Therefore, it was found that the best molecular diluent for the recovery of metals among the tested ones is C6H12, with a green protocol as the new paradigm, replacing the aqueous phase with another nonaqueous phase, i.e., a second organic diluent.

A study on the synergistic extraction of Eu(III) ions with a series of chelating ligands and determination of the process parameters is presented by employing ionic liquids and typical organic diluents. The investigations of the liquid–liquid extraction, commonly applied in the separation science of 4f and 5f-ions acidic chelating compounds, 4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-one (HP), 4-benzoyl-3-phenyl-5-isoxazolone (HPBI), and 2-thenoyltrifluoroacetone (HTTA) alone and in combination with two synergistic agents, meso-hexamethylpropyleneamine oxime (S2: HM-PAO) and its bis-imine precursor (S1: pre-HM-PAO), are presented. The interaction between the two extractants (acidic/neutral) in deuterochloroform was studied using 1H, 13C, and 1H-1H NOESY experiments. Several conclusions are given highlighting the role of the ionic diluent in complexation processes and selectivity with an employment of the two synergistic agents for various metal s-, p-, d-, and f-cations in the Periodic table, with almost 25 metal ions. The objective was to optimize a system for 4f-ions solvent extraction based on the new oxime molecules with β-diketone/isoxazolone/pyrazolone partnership. As detailed above, slight enhancements of extraction efficiencies were obtained either by using basic synergistic agents such as HM-PAO and/or using pre-HM-PAO. A competitive solvent extraction test of nearly 18 f-ions by various ligands (HTTA, S1, S2, and HPBI) and the two mixtures HTTA−S1 and HTTA−S2 diluted in ILs or organic diluents was also conducted in order to evaluate the switchable diluent impact. Additionally, electron paramagnetic resonance (EPR) spectroscopy was used to study the established chemical species with Cu2+ cations in the obtained organic extracts involving the two synergistic molecules.

A new solvent extraction system for the removal of 4f ions (Ln3+) from water by use of chelating ligands (HLn, n = 5, 6, 7, and 8) composed of heterocyclic receptors and one β-dicarbonyl fragment is reported. The covalent attachment of a β-dicarbonyl unit to a saturated N-heterocycle with variable ring size resulted in a cooperative interaction within the receptor for Ln3+ transfer, which remarkably enhanced the efficiency of the process. The intramolecular cooperative effect was observed only in the ionic liquid (IL) solvent system, providing a several-fold increase in extraction performance for Ln3+ ions (La, Nd, Eu and Dy) over chloroform. Thus, it is not possible to confirm that an identical reaction mechanism operated in both liquid systems: IL or CHCl3. The existence of neutral chelates of the type LnL3 or anionic lanthanoid complexes [LnL4−] in an ionic medium during the solvent extraction process applying various solvent systems has been established hitherto. Consequently, the Ln3+ ion was held by HLn molecules more rigidly in an IL medium ([C1Cnim+]/[C1C4pyr+]/[C1C4pip+][Tf2N−], n = 4, 6, 8, 10) than in chloroform, representing an important factor dominating the magnitude of the intramolecular cooperative effect of the chelating ligands for Ln3+ ions. The effect of the diluent’s chemical nature on the metal extraction and separation has been studied and discussed thoroughly. Furthermore, competitive solvent extraction and separation studies with various s-, p-, d-, and f-ions of the periodic table revealed that the magnitude of the intramolecular cooperative effect depends on the suitability between the metal ion size and the cavity size or flexibility of the HLn compounds. In addition, the solvent extraction process of 12 refractory metals and 8 platinum group metals with the synthesized chelating extractants is also investigated in different organic liquid media.

Medicinal plants and their derived compounds have drawn the attention of researchers due to their considerable impact on human health. Among medicinal plants, mint (Mentha species) exhibits multiple health beneficial properties, such as prevention from cancer development and anti-obesity, antimicrobial, anti-inflammatory, anti-diabetic, and cardioprotective effects, as a result of its antioxidant potential, combined with low toxicity and high efficacy. Mentha species are widely used in savory dishes, food, beverages, and confectionary products. Phytochemicals derived from mint also showed anticancer activity against different types of human cancers such as cervix, lung, breast and many others. Mint essential oils show a great cytotoxicity potential, by modulating MAPK and PI3k/Akt pathways; they also induce apoptosis, suppress invasion and migration potential of cancer cells lines along with cell cycle arrest, upregulation of Bax and p53 genes, modulation of TNF, IL-6, IFN-γ, IL-8, and induction of senescence phenotype. Essential oils from mint have also been found to exert antibacterial activities against Bacillus subtilis, Streptococcus aureus, Pseudomonas aeruginosa, and many others. The current review highlights the antimicrobial role of mint-derived compounds and essential oils with a special emphasis on anticancer activities, clinical data and adverse effects displayed by such versatile plants.

A study of the liquid–liquid extraction of ReO4− anions from hydrochloric acid solutions using the ionic liquid Aliquat 336 (QCl: trialkyl(C8–C10)methylammonium chloride) via the well-known method of slope analysis along with the determination of the process parameters is presented. This study employs CCl4, CHCl3 and C6H12 as diluents. This study was carried out at room temperature (22 ± 2) °C and an aqueous/organic volumetric ratio of unity. The ligand effect on the complexation properties of ReO4− is quantitatively assessed in different organic media. The organic extract in chloroform media is examined through 1H, 13C and 15N NMR analysis as well as the HRMS technique and UV-Vis spectroscopy in order to view the anion exchange and ligand coordination in the organic phase solution. Final conclusions are given highlighting the role of the molecular diluent in complexation processes and selectivity involving ionic liquid ligands and various metal s-, p-, d- and f-cations. ReO4− ions have shown one of the best solvent extraction behaviors compared to other ions. For instance, the Aliquat 336 derivative bearing Cl− functions shows strongly enhanced extraction as well as pronounced separation abilities towards ReO4−.

The synergistic solvent extraction of La(III), Eu(III) and Lu(III) with a chelating extractant, 4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-one (HL), and neutral bidentate heterocyclic amines, such as 1,10-phenanthroline (S1 (phen)) or 2,2′-bipyridine (S2 (bipy)) in an ionic liquid of the imidazolium family [C1C4im+][Tf2N−] was investigated. Synergistic effects have been observed to result from the formation of a ternary complex in the organic phase, particularly in cases where the ligand S is a neutral synergistic agent. Examples include La(L)2(S2)2, Eu(L)3(S2) and Lu(L)x(S2)2, as well as La(L)3(S1)2, Eu(L)2(S1) and Lu(L)3(S1)x). The parameters of the solvent extraction process were determined and the influence of the synergistic agent on the extraction process was discussed. Additionally, the synergistic increase and separation factors were determined. The equilibrated organic phases were analyzed using 1H NMR spectroscopy to elucidate the synergism in an extraction mechanism. The role of the ionic diluent in complexation processes and selectivity was investigated with the employment of the two synergistic agents for various metal s-, p-, d- and f-cations in the periodic table, with almost 22 metal ions.

Our study evaluated the in vitro antioxidant properties, antibacterial and antifungal activities, anti-inflammatory properties, and chemical composition of the essential oils (EOs), total phenol, and total flavonoid of wild Mentha pulegium L. This study also determined the mineral (nutritional and toxic) elements in the plant. The EOs were extracted using three techniques—hydro distillation (HD), steam distillation (SD), and microwave-assisted distillation (MAD)—and were analyzed using chromatography coupled with flame ionization (GC-FID) and gas chromatography attached with mass spectrometry detector (GC-MS). The antioxidant effects of the EOs were tested with 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ABTS (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), while the antibacterial and antifungal activities of the EO and methanolic extract were tested using Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. Twenty-six compounds were identified in the essential oil, representing 97.73% of the total oil, with 0.202% yield. The major components were pulegone (74.81%), menthone (13.01%) and piperitone (3.82%). Twenty-one elements, including macro- and micro-elements (Ba, Br, Ca, Cl, Co, Cr, Cs, Eu, Fe, K, Mg, Mn, Mo, Na, Rb, Sb, Sc, Sr, Th, U and Zn), were detected using neutron activation analysis (INAA) and inductively coupled plasma optical emission spectrometry (ICP-OES), with the concentration of mineral element close to the FAO recommendation. The results show that the EOs and extracts from Mentha pulegium L. had significant antimicrobial activities against the microorganisms, including five human pathogenic bacteria, one yeast (Candida albicans), and one phytopathogenic fungi. The in vivo anti-inflammatory activities of the leaf extracts were confirmed. The results indicate that the EOs and extracts from Mentha pulegium L. have promising applications in the pharmaceutical industries, clinical applications, and in medical research.

Conifers have long been recognized for their therapeutic potential in different disorders. Alkaloids, terpenes and polyphenols are the most abundant naturally occurring phytochemicals in these plants. Here, we provide an overview of the phytochemistry and related commercial products obtained from conifers. The pharmacological actions of different phytochemicals present in conifers against bacterial and fungal infections, cancer, diabetes and cardiovascular diseases are also reviewed. Data obtained from experimental and clinical studies performed to date clearly underline that such compounds exert promising antioxidant effects, being able to inhibit cell damage, cancer growth, inflammation and the onset of neurodegenerative diseases. Therefore, an attempt has been made with the intent to highlight the importance of conifer-derived extracts for pharmacological purposes, with the support of relevant in vitro and in vivo experimental data. In short, this review comprehends the information published to date related to conifers’ phytochemicals and illustrates their potential role as drugs.