Nitrophenyl-group-containing Heterocycles. Part I. Synthesis, Characterization, Anticancer Activity and Antioxidant Properties of Some New 5,6,7,8-tetrahydro-isoquinolines Bearing 3(4)-nitrophenyl Group

Regioselective cyclocondensation of 2,4-diacetyl-5-hydroxy-5-methyl-3-(3-nitrophenyl/4-nitrophenyl)cyclohexanones 1a,b with cyanothioacetamide afforded the corresponiing 7-acetyl-4-cyano-1,6-dimethyl-6-hydroxy-8-(3-nitrophenyl/4-nitrophenyl)-5,6,7,8-tetrahydro-soquinoline-3(2H)-thiones 2a,b in 93-96% yield. Reaction of compounds 2a,b with some ethyl iodide, 2-chloroacetamide (4a) or its N-aryl derivatives 4b-e by refluxing in ethanol, in the presence of slightly excess molar amounts of sodium acetate trihydrate, for one hour gave 3-ethylthio-5,6,7,8-tetrahydro-isoquinoline 3 and (5,6,7,8-tetrahydroisoquinolin-3-ylthio)acetamides 5a-i, respectively. On heating compounds 5b-d,f,g in ethanol containing a catalytic amount of sodium carbonate, they converted into their isomeric 1-amino- 6,7,8,9-tetrahydrothieno[2,3-c]isoquinoline-2-carboxamides 6b-d,f,g. Structural formulae of all synthesized compounds were characterized on the basis of their elemental analyses and spectroscopic data. Also, the biological evaluation of the synthesized isoquinolines as anticancer and antioxidant agents have been carried out and the obtained results are reported herein.

Nitrophenyl-group-containing Heterocycles. Part I. Synthesis, Characterization, Anticancer Activity and Antioxidant Properties of Some New 5,6,7,8-tetrahydroisoquinolines Bearing 3(4)-nitrophenyl Group

Regioselective cyclocondensation of 2,4-diacetyl-5-hydroxy-5-methyl-3-(3-nitrophenyl/4-nitrophenyl)cyclohexanones 1a,b with cyanothioacetamide fforded the corresponiing 7-acetyl-4-cyano-1,6-dimethyl-6-hydroxy-8-(3-nitrophenyl/4-nitrophenyl)-5,6,7,8-tetrahydro-soquinoline-3(2H)-thiones 2a,b in 93-96%. Reaction of compounds 2a,b ethyl iodide, 2-chloroacetamide or N-(naphthalen-1-yl)-2-chloroacetamide (5) in the presence of sodium acetate gave the corresponding p(5,6,7,8-tetrahydroisoquinolin-3-yl)thio derivatives 3a,b, 4a,b and 6a,b. In a similar manner, reaction of a,b with other N-aryl-2-chloroacetamides 7a-d gave 2-[(7-acetyl-4-cyano-1,6-dimethyl-6-hydroxy-8-(3-nitrophenyl/4-nitrophenyl)-5,6,7,8-tetrahydroisoquinolin-3-yl)thio]-N-arylacetamides (8a-g). On heating of compounds 8a-e in ethanol containing anhydrous sodium carbonate, they converted into 7-acetyl-1-amino-N-aryl-5,8-dimethyl-8-hydroxy-6-(3-nitrophenyl/4-nitrophenyl)-6,7,8,9-tetrahydrothieno[2,3-c]isoquinoline-2-carboxamides 9a-e. Structural formulae of all synthesized compounds were characterized on the basis of their spectroscopic data. Also, the applications of most synthesized isoquinolines as anticancer and as antioxidant agents have been carried out and the obtained results are reported herein.

Syntheses and identification of cefotaxime-non-transition metal complexes

The coordination chemistry of the biologically active cefotaxime sodium and, in particular, the mode of its interaction with some metal ions of electronic configuration d0 (alkaline earth) and others, Zn(II), Pb(II), and Ce ions with the electronic configuration d10 has been investigated. Seven complexes were synthesized, isolated in the solid-state, and characterized by elemental analyses, conductivity measurements, IR and UV/VIS spectra, as well as thermal analyses. Based on the obtained experimental data and literature, the structural formulae to these complexes were suggested and formulated as [Mg(cef)2].2H2O (1), [Ca(cef)2].2H2O (2) [Sr(cef)2].2H2O (3), [Ba(cef)2].2H2O (4), [Zn(cef)2(H2O)2] (5), [Pb(cef)2(H2O)2].4H2O (6) and [Ce(cef)2(H2O)2].3H2O (7). The data obtained show that cefotaxime interacted with metal in a molar ratio of 2:1, respectively. Cefotaxime bonded to metal ions in the anionic form as a bidentate ligand through the lactam carbonyl (C=O) and the carboxylate group (COO-). Tetrahedral and octahedral shapes were proposed as the most likely geometries associated with a metal having such electronic configurations. The absorption bands observed in the electronic spectrum of free cefotaxime are also observed with some shifts in the spectra of its complexes, indicating their formation. The absorption bands of free cefotaxime and its complexes were assigned to electronic transitions. The thermal analyses date strongly support the structures proposed for the complexes and indicate the formation of the corresponding metal oxide as a final decomposition product.

On the structural formula of smectites: a review and new data on the influence of exchangeable cations

The understanding of the structural formula of smectite minerals is basic to predicting their physicochemical properties, which depend on the location of the cation substitutions within their 2:1 layer. This implies knowing the correct distribution and structural positions of the cations, which allows assigning the source of the layer charge of the tetrahedral or octahedral sheet, determining the total number of octahedral cations and, consequently, knowing the type of smectite. However, sometimes the structural formula obtained is not accurate. A key reason for the complexity of obtaining the correct structural formula is the presence of different exchangeable cations, especially Mg. Most smectites, to some extent, contain Mg2+ that can be on both octahedral and interlayer positions. This indeterminacy can lead to errors when constructing the structural formula. To estimate the correct position of the Mg2+ ions, that is their distribution over the octahedral and interlayer positions, it is necessary to substitute the interlayer Mg2+ and work with samples saturated with a known cation (homoionic samples). Seven smectites of the dioctahedral and trioctahedral types were homoionized with Ca2+, substituting the natural exchangeable cations. Several differences were found between the formulae obtained for the natural and Ca2+ homoionic samples. Both layer and interlayer charges increased, and the calculated numbers of octahedral cations in the homoionic samples were closer to four and six in the dioctahedral and trioctahedral smectites, respectively, with respect to the values calculated in the non-homoionic samples. This change was not limited to the octahedral sheet and interlayer, because the tetrahedral content also changed. For both dioctahedral and trioctahedral samples, the structural formulae improved considerably after homoionization of the samples, although higher accuracy was obtained the more magnesic and trioctahedral the smectites were. Additionally, the changes in the structural formulae sometimes resulted in changing the classification of the smectite.

Triple molybdates K3–x Na1+x M 4(MoO4)6 (M = Ni, Mg, Co) and K3+x Li1–x Mg4(MoO4)6 isotypic with II-Na3Fe2(AsO4)3 and yurmarinite: synthesis, potassium disorder, crystal chemistry and ionic conductivity

The triple molybdates K3–x Na1+x M 4(MoO4)6 (M = Ni, Mg, Co) and K3+x Li1–x Mg4(MoO4)6 were found upon studying the corresponding ternary molybdate systems, and their structures, thermal stability and electrical conductiviplusmnty were investigated. The compounds crystallize in the space group R 3 c and are isostructural with the sodium-ion conductor II-Na3Fe2(AsO4)3 and yurmarinite, Na7(Fe3+, Mg, Cu)4(AsO4)6; their basic structural units are flat polyhedral clusters of the central M1O6 octahedron sharing edges with three surrounding M2O6 octahedra, which combine with single NaO6 octahedra and bridging MoO4 tetrahedra to form open three-dimensional (3D) frameworks where the cavities are partially occupied by disordered potassium (sodium) ions. The split alkali-ion positions in K3–x Na1+x M 4(MoO4)6 (M = Ni, Mg, Co) give their structural formulae as [(K,Na)0.5□0.5)]6(Na)[M1][M2]3(MoO4)6, whereas the lithium-containing compound (K0.5□0.5)6(Mg0.89K0.11)(Li0.89Mg0.11)Mg3(MoO4)6 shows an unexpected (Mg, K) isomorphism, which is similar to (Mn, K) and (Co, K) substitutions in isostructural K3+x Li1–x M 4(MoO4)6 (M = Mn, Co). The crystal chemistry of the title compounds and related arsenates, phosphates and molybdates was considered, and the connections of the cationic distributions with potential 3D ionic conductivity were shown by means of calculating the bond valence sum (BVS) maps for the Na+, Li+ and K+ ions. Electrical conductivity measurements gave relatively low values for the triple molybdates [σ = 4.8 × 10−6 S cm−1 at 390°C for K3NaCo4(MoO4)6 and 5 × 10−7 S cm−1 at 400°C for K3LiMg4(MoO4)6] compared with II-Na3Fe2(AsO4)3 (σ = 8.3 × 10−4 S cm−1 at 300°C). This may be explained by a low concentration of sodium or lithium ions and the blocking of their transport by large potassium ions.

Spanish Bentonites: A Review and New Data on Their Geology, Mineralogy, and Crystal Chemistry

A review and a synthesis of the geological, mineralogical, and crystal chemical data available in the literature on active Spanish bentonitic exploitations were done, and at the same time, new data are provided from a set of representative samples from these deposits. They were located in three different areas with different geological origins: (1) Miocene sedimentary deposits from the Tajo Basin (Madrid–Toledo provinces) in the center of the Iberian Peninsula, where bentonites appear in two different units named for their colors (Green Clays and Pink Clays); (2) samples from Tamame de Sayago (Zamora province) originating from the hydrothermal alteration of granitic Variscan rocks; and 3) Miocene deposits originating from the hydrothermal alteration of volcanic or subvolcanic rocks from the Cabo de Gata volcanic area (Almería Province) in the southern part of Spain, where the three main deposits (Cortijo de Archidona, Los Trancos, and Morrón de Mateo) were studied. The bentonites from the Tajo Basin were formed mainly by trioctahedral smectites, and there were significant mineralogical differences between the Green and Pink Clays, both in terms of the contents of impurities and in terms of smectite crystallochemistry and crystallinity. The smectites from Tamame de Sayago were dioctahedral (montmorillonite–beidellite series), and they appeared with kaolinite, quartz, and mica in all possible proportions, from almost pure bentonite to kaolin. Finally, the compositions of the bentonites from the three studied deposits in Cabo de Gata were quite similar, and zeolites and plagioclases were the main impurities. The structural formulae of the smectites from Cortijo de Archidona and Los Trancos showed a continuous compositional variation in beidellite–montmorillonite, while in Morrón de Mateo, the smectites were mainly montmorillonite, although there was continuous compositional variation from Al montmorillonites to Fe–Mg-rich saponites. The variation in the smectite composition is due to the intrusion of a volcanic dome, which brings new fluids that alter the initial composition of the smectites.

How to visualize the different lactose content of dairy products by Fearon’s test and Woehlk test in classroom experiments and a new approach to the mechanisms and formulae of the mysterious red dyes

The article connects historical developments in analytics with contexts of today and school experiments: Woehlk test and Fearon’s test are historically known as the reactions of lactose and maltose with ammonia and methylamine, respectively. Both lead to characteristic red dyes whose formation and structural formulae had not been of interest or had even been reported incorrectly until 2015. Even though these tests, developed in the first half of the twentieth century, are obsolete in medicinal analysis today, they pose interesting experiments for school chemistry, when investigating the topic of macromolecules or sugars. In an inquiry or context-based teaching approach, tests visualizing different lactose concentrations in different dairy products would fit into the contexts milk and chemical detection of diseases. The experiments can also be used in a historically based problem-oriented approach in which the scientists, their work and lives can be the central perspective. As both methods of analysis result in brightly colored solutions, they are easily interpretable as well as aesthetically appealing to students. As the test developed by Fearon is quicker and makes use of less dangerous chemicals, it is the one to be preferably used in school.

Fistuloates A–C: New antioxidative aromatic compounds isolated from Cassia fistula

Three new aromatic compounds named fistuloates: A (3-butyl-6-ethylnonyl-3-(1-phenylethyl) benzoate), B (3-(6- tert-butyl-1-ethoxy-5-ethyl-4-methylnonyl)-5-ethylbenzoic acid isobutyl ester) and C (4,5-diethoxy-2-propylbenzoic acid 7-(6-pentyltetrahydropyran-2-yl)-heptyl ester) were isolated from the ethyl acetate soluble fraction of Cassia fistula Linn. The structural formulae of the isolated compounds A–C were established through interpretation of their spectral data. Compounds A–C exhibited significant antioxidant properties in 2,2-diphenyl-1-picrylhydrazyl, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and superoxide anion radical scavenging assays that signifies that C. fistula carries potential anti-oxidant constituents and may assist to cure diseases associated with oxidative stress and others.

AntiHIV-Pred: web-resource for in silico prediction of anti-HIV/AIDS activity

Motivation Identification of new molecules promising for treatment of HIV-infection and HIV-associated disorders remains an important task in order to provide safer and more effective therapies. Utilization of prior knowledge by application of computer-aided drug discovery approaches reduces time and financial expenses and increases the chances of positive results in anti-HIV R&D. To provide the scientific community with a tool that allows estimating of potential agents for treatment of HIV-infection and its comorbidities, we have created a freely-available web-resource for prediction of relevant biological activities based on the structural formulae of drug-like molecules. Results Over 50 000 experimental records for anti-retroviral agents from ChEMBL database were extracted for creating the training sets. After careful examination, about seven thousand molecules inhibiting five HIV-1 proteins were used to develop regression and classification models with the GUSAR software. The average values of R2 = 0.95 and Q2 = 0.72 in validation procedure demonstrated the reasonable accuracy and predictivity of the obtained (Q)SAR models. Prediction of 81 biological activities associated with the treatment of HIV-associated comorbidities with 92% mean accuracy was realized using the PASS program. Availability and implementation Freely available on the web at http://www.way2drug.com/hiv/. Supplementary information Supplementary data are available at Bioinformatics online.

Structure Elucidation and Toxicity Analysis of the Degradation Products of Deoxynivalenol by Gaseous Ozone

Fusarium Head Blight (FHB) or scab is a fungal disease of cereal grains. Wheat scab affects the yield and quality of wheat and produces mycotoxins such as deoxynivalenol (DON), which can seriously threaten human and animal health. In this study, gaseous ozone was used to degrade DON in wheat scab and the degradation products of ozonolysis were analyzed by ultra-performance liquid chromatography quadrupole-orbitrap mass spectrometry (UHPLC Q-Orbitrap). Toxicology analyses of the degradation products were also studied using structure-activity relationships. Ozone (8 mg L−1 concentration) was applied to 2 μg mL−1 of DON in ultrapure water, resulted in 95.68% degradation within 15 s. Ten ozonized products of DON in ultrapure water were analyzed and six main products (C15H18O7, C15H18O9, C15H22O9, C15H20O10, C15H18O8, and C15H20O9) were analyzed at varying concentrations of ozone and DON. Structural formulae were assigned to fragmentation products generated by MS2 and Mass Frontier® software. According to structure-activity relationship studies, the toxicities of the ozonized products were significantly decreased due to de-epoxidation and the attack of ozone at the C9-10 double bond in DON. Based on the results of the study above, we can find that gaseous ozone is an efficient and safe technology to degrade DON, and these results may provide a theoretical basis for the practical research of detoxifying DON in scabby wheat and other grains.