In this work, we realized a theoretical study of the behavior of N-tosylacylpyrroles and N-tosylacylindoles being electrophilic dienophiles in polar Diels-Alder reactions joint to different nucleophilic dienes: isoprene, 1-trimethylsiloxy-1,3-butadiene, and Danishefsky's diene. Calculations were developed considering the experimental results of these reactions in thermal conditions. The computational theorical methods employed are based in the Density Functional Theory. Electrophilicity and nucleophilicity indexes, based in the energy of frontier molecular orbitals HOMO and LUMO, were the parameter used to explore the feasibility of the cycloaddition. It was observed that the acyl pentaheterocycles suffer the cycloaddition yielding indol derivatives, and, the benzofused ones convert into carbazole derivatives. The regioselectivity was predicted using the Fukui function to achieve local electrophilicity and nucleophilicity indexes. Also, the reaction mechanisms of some selected cases were analyzed in order to understand the reaction path. Considering the mechanism study, a unique and notably asynchronous transition state was found between the reactants and the primary cycloadduct.  As a consequence of the theoretical study we can conclude that these reactions are concerted and asynchronous cycloadditions and that the sterochemistry is defined by the acyl group in the dienophile and the substituent groups of the dienes. Only the reactions where Danishefsky's diene participates are completely regioselective.

Metal ions are of great significance to the environment and biological system. Particularly, trivalent - iron, aluminium and chromium - and divalent - copper, mercury, cadmium, and zinc - cations are some of the more important. Among the different chemosensors, those based on ion-induced changes in fluorescence are especially suitable as they are easy to use and usually give an instantaneous response with high sensitivity.

Recently we have designed and synthesized two new ligands derived from bis-vanillin. Both ligands were studied as fluorimetric sensors of trivalent cations. It was concluded that a combination of them can be used to discriminate between Fe³⁺, Al³⁺ and Cr³⁺.

Based in these results, we present a theoretical study based on the Functional Density Theory related to the complexation types of both ligands with M³⁺ cations, which structures contained a hydrazoline or isoniazide moiety. Moreover, we realize a predictive theoretical study to explore the ligands' complexation with M²⁺ cations.  The optimized structures of the ligands and their cation complexes are presented and discussed. In addition, for the M³⁺ complexes, we analyze the changes in the dihedral angle of the complexes structures and their connection with the experimental observations. The global energies of the optimized structures show that the complexes possess less energy than the isolated ligands. On the other hand, in all the cases the values ​​of the difference between HOMO and LUMO energies are determined to compare the energy gap and relate them to the effects observed in the UV bands.

A docking studies of a set of several 1,5-disubstituted tetrazoles (1,5-DS-T) compounds to find potential inhibitors of the Abelson tyrosine-protein kinase (ABL kinase) and the mutated ABL kinase T315I were conducted by using Lamarckian genetic algorithms as search algorithms in Autodock4. Bayesian calculations were performed, and specificity (Sp) and sensitivity (Se) values as well as positive predicted values (PPVs) and negative predicted values (NPVs) were calculated using a set of 99 active ligands and 385 decoys for ABL kinase from the DUD database. RMSD values were calculated between the X-ray crystallographically determined coordinates of the ligands in the complexes of ligand with the ABL kinase and with T315I ABL kinase resistant to imatinib. The predicted results showed the importance of the interactions of the protein with halogens present in some of these 1,5-DS-T ligands. In conclusion, the results suggest that eight novel 1,5-DS-T compounds were identified to be effective inhibitors of ABL kinase.

A series of imine analogs of anticancer drug imatinib were synthesized in moderate to good yields, under ecofriendly conditions. Some compounds containing fluorine atoms and important medicinal chemistry scaffolds such as chromone, pyridine and pyrrole. These compounds could have potential applications in medicinal chemistry as antifungal, antibacterials and mainly Abl tyrosine kinase inhibitors.

            Natural and synthetic polymers and plastics made of them, are an integral part of the urban environment  in many different areas . Polyethylene is one of the most widely used polymers. Production of films of different kinds and purposes is determined by the specific properties of polyethylene. Among the polymers and polymeric materials only a small portion can be considered non-flammable. The vast majority (including the above-mentioned polyethylene) undergoes a process of thermal destruction under the influence of a sufficient amount of energy, emitting a considerable amount of heat and smoke. Studies on the flammability of polymers and methods of its reduction are driven by factors of ecological, economic and safety aspects.

            The experimental section describes a procedure for preparing a film material and a comparison of properties, with respect to the used filler: colloidal silica, calcium phosphate or hydroxyapatite. With Differential Scanning Calorimetry (DSC) we tested properties such as melting and crystallisation temperature, heat of fusion and the content of crystalline phase. Studies were carried out using the flammability test LOI UL-94 and microcalorimetry of pyrolysis-combustion to determine the burning rate, the limiting oxygen index as well as the rate and the amount of released heat. Optical microscopy was also used to examine the morphology of the polymer matrix.

            On the basis of the results, the modification of polyethylene matrix was found effective. The addition of fillers had a significant impact on the mechanism of combustion of the investigated films. It revealed a reduction in burn rate, a reduction in rate and amount of released heat and an increase of the value of LOI. At the same time, there were no significant effects on the other properties of the composites. The most prominent flame retardant effect as compared to a pure polyethylene film was provided by hydroxyapatite. There was no occurrence of synergistic effect between the phosphorus compounds and the silica, so there is no reason to apply them in such combination as a mixture of fillers, giving the effect of fire retardant in the composite material.

The process of bonding and adhesives are an important part of human life from the earliest times. Over the years, a development has evolved. Natural adhesives were increasingly replaced by synthetic, which allowed to obtain more permanent weld and glue together  different types of materials. Despite the emergence of new industrial sectors which allowed to connect components such as soldering, welding, thermal bonding, rivets, screws or pins gluing process did not lose in significance. People are willing to use the features and ease of use adhesives. Ecological aspects, however, pay attention to the safety of the environment. Decreasing non-renewable sources and the growing amount of waste affects the market, on which to a greater extent firms appear with environmentally friendly technologies. An important field of biodegradable polymers are produced from renewable raw materials that do not affect negatively the environment. Nowadays, more and more research is conducted to increase the scope of their use.

The experimental section presents a method to prepare polylactide paper adhesives and the effects of additives on its properties. The first part  a review of the latest scientific and patent literature towards polylactide biocomposite adhesives. This review shows a lack of studies on polylactide adhesives in the literature. This led to a series of experimental studies related to the selection of  appropriate adhesive formulations, as well as additives favorably affecting  the strength of the glued joints. The object of the study were the four compositions with the same concentration (polylactide dissolved in chloroform - primary composition, the composition containing pigments, the composition containing the essential oil and the composition with corn flour).

The resulting compositions were subjected to a series of experimental studies such as: rheological tests including measurements of viscosity and thixotropy, peel strength, wettability and penetration, content of solids and creep tests. The lifetime of adhesives were determined, and we finally propose a method and the respective conditions for their long-term storage.

Recently, interest in food of plant origin and its pro-health properties have increased. Plant products due to significant antioxidant activity should be a constant part of the human diet. Elderberry is a plant with high potential as a source of functional component obtained from flowers, fruits, bark and roots.  Wild elderberry flowers are used as a antipyretic, diuretic and sealing blood vessels. On the other hand elderberry fruits are known as the source of many substances that have detoxifying, antiviral and strengthening effects on human body. Outside of therapeutic significance both fruits and flowers are used increasingly in the food industry. Micelle-mediated separation is similar to traditional liquid-liquid extraction. In this method the organic solvent is replace with an aqueous surfactant solution. Micelles are colloidal type cluster that are spontaneously formed when the concentration of surfactant molecules increase above called critical micellar concentration (cmc).The aim of this work was to extract bioactive components from elderberry (Sambucus nigra) fruits and flowers by means of various extraction solutions. The extraction solution were WPC (whey protein concentrate) and WPI (whey protein isolate) solution. Comparative extracts were also made using ethanol solutions and distilled water as control. Obtained extracts were analyzed by determination of: total reduction capacity using Folin-Ciocalteu reagent, flavonoid content, antioxidant activity using DPPH reagent. In WPC and WPI protein extracts, the extraction of bioactive components is more efficient than in the case of water extraction. This could be seen at the lowest concentration of both WPI and WPC. The work was financed by scientific grant
No. DS3700/WTZ/2017

Indole frameworks or scaffold are the most heterocyclic compounds in many biological systems that show medicinal properties and pharmacological activity.¹ During the past, a large numeral of natural products containing bis(indolyl)methanes (BIM’s), which contain two indole or substituted indole units in a molecule, have been isolated from marine sources. The BIM’s exhibit antibacterial, antibiotics, analgesic and anti-inflammatory activities. They are also highly beneficial in promoting good estrogen and increase the body’s natural metabolism of hormones.^2,3

In continuing to our ongoing efforts towards developing efficient catalysts for different MCRs ^4,5, we report herein heteroaromatic isocyanurate ring functionalized MCM-41, as a new, efficient and recoverable catalyst, for the synthesis of BIM derivatives (Scheme 1).

­ Scheme 1. Representative examples of biologically active bisindolylmethane (BIM) derivatives.

References

(1) Shiri, M. Chemical reviews 2012, 112, 3508.

(2) Sarva, S.; Harinath, J. S.; Sthanikam, S. P.; Ethiraj, S.; Vaithiyalingam, M.; Cirandur, S. R. Chinese Chemical Letters 2016, 27, 16.

(3) Yaghoubi, A.; Dekamin, M. G.; Arefi, E.; Karimi, B. Journal of Colloid and Interface Science 2017, 505, 956.

(4) Dekamin, M. G.; Azimoshan, M.; Ramezani, L. Green Chemistry 2013, 15, 811.

(5) Dekamin, M. G.; Kazemi, E.; Karimi, Z.; Mohammadalipoor, M.; Naimi-Jamal, M. R. International journal of biological macromolecules 2016, 93, 767.

Indole frameworks have been extensively known as vital moieties in biological, agrochemical and pharmacological compounds.¹ Several MCR methods have been reported for the synthesis of substituted indoles. Within indole derivatives, 3-substituted indoles are versatile intermediates for the synthesis of a widespread range of indole compounds. The conjugate addition of indoles to Michael acceptors affords easy access to 3-substituted indole derivatives. ²

In continuing to our ongoing efforts towards developing efficient catalysts for different MCRs^3,4, we report herein a general route to 3-substituted indole derivatives via the three-component reaction of indoles, malononitrile and aldehydes promoted by a new alkaline functionalized chitosan, as a highly efficient and recoverable catalyst (Scheme 1).

­ Scheme 1. The three-component reaction of aldehydes, indole and malononitrile.

References

(1) Shiri, M. Chemical reviews 2012, 112, 3508.

(2) Qu, Y.; Ke, F.; Zhou, L.; Li, Z.; Xiang, H.; Wu, D.; Zhou, X. Chemical Communications 2011, 47, 3912.

(3) Dekamin, M. G.; Azimoshan, M.; Ramezani, L. Green Chemistry 2013, 15, 811.

(4) Dekamin, M. G.; Kazemi, E.; Karimi, Z.; Mohammadalipoor, M.; Naimi-Jamal, M. R. International journal of biological macromolecules 2016, 93, 767.

Many optically active compounds exhibit important and desirable biological properties. One way of carrying out enantioselective reactions to produce optically pure compounds is the use of chiral catalysts. Among many catalysts, transition metal complexes with different types of chiral ligands play a very important role. Bisphosphine ligands are among the most important class of ligands used in transition metal catalysis. The search for new structures of ligands and complexes and their use in stereocontrolled reactions is an important direction of research. An important aspect in the search for new ligands is the use of natural, renewable and easily accessible chiral precursors. Monoterpenes, especially alpha-pinene and camphor, fill these rules very well. In our previous studies, we have shown that the use of a rigid bicyclic pinane structure as a framework for the construction of chiral spiroborate esters¹ or PHOX² ligands gives good results.

Herein, we present the new approach to the synthesis of rigid bicyclic chiral bisphosphines derived from α-pinene. Thus, α-pinene is transformed into isopinocamphone or verbanone and these ketones are converted to spiroepoxides. Controlled reduction of epoxides with borane gives allylic alcohols, which are transformed into bisphosphines by previously developed methods.

We wish to thank for the financial support from National Science Centre Preludium 4 No. 2012/07/N/ST5/02194.

¹ Ćwiklińska M., Krzemiński M. P., Tafelska-Kaczmarek A., Tetrahedron: Asymmetry 2015, 26, 1453-1458.

² Kmieciak A., Krzemiński M. P., Tetrahedron: Asymmetry 2017, 28, 467-472.