In the present work, the synthesis and biological activity of substituted 2-aminopyridine δ-lactones derivatives were achieved. 4,6,6-trimethyl-2-oxo-5,6-dihydro-2H-pyran-3-carbonitrile was synthetised from 4-hydroxy-4-methylpentan-2-one and then its enaminonitrile was obtained with DMFDMA. This enaminonitrile with amines gave substituted 2-aminopyridine δ-lactones identified by various spectroscopic methods (IR, ¹H NMR, ¹³C NMR and MS). The antioxidant effects of substituted 2-aminopyridine δ-lactones derivatives were evaluted through DPPH assay and revealed a great antioxydant capacity.The antifungal and antibacterial activities were tested by disc diffusion method against clinical Gram-negative bacteria and against clinical fungi. The study shows moderate to very good antibacterial and antifungal activities for the new substituted 2-aminopyridine δ-lactones derivatives.

Ricinine is an alkaloide of Ricinus commununis posseding numerous biological properties.

Ricinidine (1-Methyl-2-oxo-1,2-dihydro-3-pyridinecarbonitrile) and new N-analogues of Ricinidine were obtained by the reaction of ethyl α-ethoxyethylidenecyanoacetate with amines. The ethyl α-ethoxyethylidenecyanoacetate was prepared from ethyl cyanoacetate. Biologically amines as tryptamine and histamine were used in order to introduced a second pharmacophore.

BODIPYs involving styryl groups at the 3/5 BODIPY positions have demonstrated interest as readily accessible red-to-NIR chromophoric platforms for the development of smarter dyes for advancing biophotonic applications, including smarter photosensitizers for photodynamic therapy (PDT) and phototheragnosis.

In this context, we have recently discovered the capability of highly-fluorescent 3-styryl- and 3,5-distyrylBODIPYs, bearing tripheynylphosphonium groups at their styryl moieties, to serve as a new type of heavy-atom-free red phototheragnostic agents, due to enhanced PDT triggered by their selective accumulation into mitochondria. The specific targeting of these organelle is achieved by the role of the tripheynylphosphonium groups, due to the well-known mitochondria membrane potential (160–180 mV; negative inside).

We were interested in exploring whether this amazing PDT activity, surprisingly coming from a highly fluorescent dye, could be also achieved by using other delocalized cations instead of tripheynylphosphonium or, even, non-delocalized cations (e.g., quaternary ammonium salts). To this aim, we found it interesting to carry out a preliminary study on the use of styryl moieties functionalized with ammonium cations (directly linked to the styryls or through suitable spacers avoiding electronic conjugation) for the rapid construction of new mitochondria-targetable phototheragnostic red styrylBODIPYs. This communication reports the preliminary results obtained from such a study, which could allow designing improved red-to-NIR PDT agents free of heavy atoms.

We define a new strategy to develop, through a straightforward and low cost synthetic protocol, two BODIPYs with red-absorption and good fluorescence ability. These novel BODIPYs, were functionalized by Knoevenagel condensations with styryl moieties that present non-delocalized cations (trimethylammonium salt) attached to the BODIPY through a spacer, or directly linked. This approach has been exemplified by the development of new dyes for cell bioimaging. The preliminary results over one them show, successfully internalize into Hela cells and accumulate in the mitochondria. In vitro suitability for photodynamic therapy (PDT) was also analyzed in this derivative and confirmed that it’s a mitochondria-targetable phototheragnostic red styrylBODIPYs.

A composite based on three components including PMMA (polymethyl metacrylate), HA (hydroxyl apatite) and LDH (layered double hydroxide) was prepared, characterized and applied as bone cement.

Bone cement is a biomaterial performs in clinical applications by fixing joint replacements in hip and knee joints. There are four types of bone cements, two of which applied in dentistry and orthopedics are polymer-based including a) Acrylic cements based on PMMA, b) Cements based on PPF (polypropyl fumarate). LDH with the general formula of [M(II)_1-xM(III)_x(OH)₂]^x+.(A^n-)_X/n· mH₂O has M(II) and M(III) cations and A^n- inter-layer anion. The importance of LDH is for its planar layered structure. HA is a thermodynamically stable calcium phosphate similar to the human hard tissues in morphology and composition.

In this work, we have prepared a Zr-CoLDH with a green method and mixed it with PMMA and HA in a given ratio. In order to characterize the composite, XRD, FTIR and SEM analyses are done.

A novel synthetic method has been developed by utilizing the chemical reactivity of functionalized graphene and CNT with a covalent combination of chemically diverse GO/FCNT and toluene diisocyanate. Thereby yield a synergistic polymer nanocomposite. Comprehensive composite material has simultaneous covalent as well as π-π interactions confirms sp2-hybridized frameworks of graphene oxide and MWCNTs by Raman absorption spectra at 1345 and 1590 cm^-1 of D and G band respectively. Toluene diisocyanate and GO/FCNT inspired polymeric formulation obtained by the classical curing reaction initiated by ultrasound sonication. This method allowed 50 wt. % doping of GO/FCNT without segregation ensures good adhesion to the law steel surface. Large surface area and morphological character of GO and FCNT by SEM and TEM ensure stable and dispersed integrated molecules. It has advantages over the high-temperature hazardous curing reaction overcomes the problem of graphene exfoliation and does not allow CNT slipping within the bundle to falls apart at higher concentration.

A regioselective method for the preparation of p-tolyl-substituted alkanes based on the reaction of dialkyl-substituted alkynes with 4 equiv. of TaCl₅ or NbCl₅ in the presence of stoichiometric amounts of metallic magnesium in toluene solution. It was found that the reaction of 5-decyne with the TaCl₅-M reagent system (where М = Mg, Zn, Fe, Sm, Al, Mn) in a toluene solution is accompanied by the selective formation of 1-(decan-5-yl)-4-methylbenzene in a high yield (79-90%). The effect of solvents on the selectivity of the conversion of 5-decyne under the action of the TaCl₅-Mg reagent system has been studied.

Green chemistry as a powerful tool plays momentous role in various research fields such as synthetic organic, biomedical, industrial chemistry, In summary, an efficacious method is described for the synthesis of spirooxindole derivatives using Fe₃O₄@SiO₂@Pr-Tris(aminomethyl)amine a green catalyst. This is a one-pot three-component condensation in water as a clean and environmentally favorable media. The present procedure proposes various remarkable privileges such as mild reaction conditions, simple work-up procedure and environment friendly. Moreover, the catalyst used is easily recovered by the external magnetic field and reused without significant deterioration in catalytic activity after at least five times.

Organic-inorganic hybrids (OIH) are a versatile type of material that joins organic and inorganic moieties in a polymeric matrix and can be easily synthesized by sol-gel method. OIH can be doped with chemosensors to yield an ion-sensitive polymeric matrix that can be used in the design of a more complex sensory device. Heterocyclic aldehydes show promising optical properties for supramolecular interactions with different ions, through molecular recognition and changes in the optical signal. Cu(II) is a cation with biological and environmental relevance, being an appealing target for the design of chemosensors.

Following the group’s work on OIH materials and heterocyclic chromophores/fluorophores, this work reports the synthesis and characterization of an OIH based on Jeffamine THF-170 and 3-isocyanatopropyltriethoxysilane (3-ICPTES), doped with a previously synthesized heterocyclic aldehyde that features a naked-eye detection of Cu(II). Additionally, the organic-inorganic hybrid material show color changes in the presence of Cu(II). Therefore, the obtained material shows promising properties to be used in the development of an optical fiber sensor for Cu(II) detection.

Although the most common types of secondary structures in proteins are helices and sheets, other types of structures are also formed, such as turns and loops.

Turns play an important role, both structurally and functionally. With regard to the structural aspect, they intervene in the folding of the peptide chain, favouring the formation of a specific tertiary, globular or fibrous structure. With regard to the functional aspect, the turns are mainly located in the region of the proteins most exposed to the environment, and therefore influence various processes, such as molecular and cellular recognition, as well as interactions between peptide structures and non-peptide substrates or receptors. In addition, the turns serve as templates for the design of new drugs, antigens and pesticides.

The serine-proline sequence, in terms of its ability to induce β-turns, is present in proteins that regulate gene expression and DNA binding. In addition, this sequence is recognised as a substrate by numerous kinases, representing a preferential site for protein phosphorylation.

As an application of our work on the synthesis of dihydroxyprolines, we will discuss the ability of the dihydroxyproline-proline domain to induce the formation of β-turns similar to those induced by the serine-proline pair in synthetic peptides. To this end, it is proposed to incorporate the proline-dihydroxyproline dimer (in blue) into peptide II. This novel peptide supports the possibility of formation of hydrogen bonds similar to those of peptide I, which incorporates the serine-proline sequence (in blue).

The search for structures that fold in the form of peptide turns, in which α-amino acids are totally or partially replaced by constraints made up of β- or γ-amino acids is of great interest. But so are those structures in which α-amino acids are amino acids are replaced by non-amino acid molecules, which also give rise to peptide turns. The interest, in both cases, is due to the limitations of the α-peptides, mainly its low structural diversity, due to the limited number of proteinogenic acids as well as its remarkable conformational flexibility and low metabolic stability.

This communication deals with the turn inducer properties of peptidomimetic I. Its synthesis and structural study will be discussed.