The pathogenicity and virulence of Mycobacterium tuberculosis have further potentiated its infectiousness thereby making it a killer disease as evident from the WHO database. Eradicating the TB epidemic by 2030 is amongst the major health targets of the United Nations Sustainable Development Goals (SDGs). The increase in multidrug-resistant TB (MDR-TB) cases has challenged and prompted the scientific community to develop novel chemotherapeutic agents with novel mechanisms of action. This can be achieved by the concept of “conditionally essential target” (CET)-based drug design. The research pertaining to the Mycobactin biosynthesis pathway (MBP) relating to iron acquisition is at a nascent stage and serves as a promising endogenous target for novel lead compounds discovery (non-specific MBP inhibitors). In continuation to our previous research work reported by Stirret et al, 2008 and Ferreras et al., 2011; here we further aim to explore the structural diversity of the previously identified active molecules which could lead to the discovery of a more potent analog. Eventually, we designed a small library of mycobactin analogs retaining the basic scaffold as diaryl-substituted pyrazoline (DAP) and tested their insilico stability by molecular docking (AutoDock 4.2.6). Docking of the designed molecules was performed in the active site of the receptor (PDB: 5KEI; by analogy with the related structure PDB: 1MDB) to evaluate the binding modes and inhibitory profile. The lowest energy conformation of each docked ligand was analyzed in BIOVIA Discovery Studio Visualizer. Docking results showed that the designed compound GS was found to be more potent and could serve as a lead compound. The ADMET profile also revealed satisfactory results. Further, these results can be validated using MD simulation and intracellular activity.

Cyanine dyes are widely used as fluorescent labels in many biomedical applications, such as cancer imaging, enzyme assay, nucleic acid detection, and biomolecular labeling. This is due to their excellent spectral properties, including narrow absorption bands, large molar absorption coefficients and an intense π-π* absorption which can be easily tuned by structural modifications in the chromophore moiety. Among these dyes, pentamethine cyanine (Cy5) fluorophores which emit in the NIR region can be used to effectively reduce the background signal arising from auto-fluorescence of the biological matrix and light scattering. For this reason, pentamethine dyes have been employed as donor/acceptor groups in FRET-based fluorescent probe to study biological processes in vitro and in vivo.

Having these facts in mind and considering our interest in the synthesis of FRET-labelled peptide substrates for in vitro validation of a nanoconstructed drug delivery system, we report herein the synthesis and characterization of a pentamethine cyanine dye. Its structure contains two sulfonic acid groups to increase its aqueous solubility and a carboxylic acid group, which can be activated to form succinimidyl ester and thus be conjugated to a specific peptide. The pentamethine dye preparation was performed by traditional solution phase chemistry and the desired compound was characterized by NMR, UV/Vis absorption and fluorescence spectroscopy.

In recent years, push-pull dicyanovinyl derivatives have been reported for several optical applications, including as fluorescent probes for cyanide ion detection. In presence of cyanide ions, this type of compound exhibits an ICT mechanism associated with the addition of the cyanide ion to the β-position of the dicyanovinyl group, due to the strong electron-withdrawing effect of the cyano groups. These structural changes caused by the addition reaction are accompanied by changes in the probe’s absorption and emission.

In this communication, we report a thiophene-based dicyanovinyl derivative and its prospective application as an anion chemosensor. The photophysical characterization was carried out in acetonitrile and aqueous acetonitrile solutions. Preliminary sensing assays in the presence of various anions of biological, medicinal and environmental relevance and spectrophotometric titrations on relevant anions will be presented.

Insect resistance to pesticides, resulting from factors like the frequency of resistance alleles, pest management practices and cross-resistance, provoke loss to agriculture and consequences on public health. The development of alternative pesticides could help to circumvent this significant limitation.
Carboxamide compounds have shown insecticidal effects against insect pest such as Spodoptera litura, or mosquitoes Aedes aegypti; the pyrazole carboxamide chlorantraniliprole and the benzamide broflanilide have been placed on the market by agrochemical companies.
Considering the above-mentioned facts, and in continuation of our recent interests in pesticides, in the present work a series of benzamide derivatives was synthesised in order to predict their potential as insecticides. In addition, an in silico inverted virtual screening protocol considering the 13 common insecticide protein targets was used to evaluate the potential insecticide activity of these molecules and identify the most likely targets. The results suggest important clues for the development of this class of derivatives as alternative insecticides.

The synthesis of the five new bis-furanyl-pyrrolo[3,4-b]pyridin-5-ones 1a-e in 24 to 40% yields through a domino sequence based on the Ugi-Zhu three-component reaction is presented. Then, on the main protease M^Pro (PDB: 6lu7) from the SARS-CoV-2, the synthesized products and co-crystallized ligands of M^Pro were in silico evaluated using the docking technique, finding moderate to good binding energies and some interesting interactions, suggesting that some bis-furanyl-pyrrolo[3,4-b]pyridin-5-ones may be used for further in vitro assays against the virus.

New para-aminobenzoic acid (PABA) grafted on silica-coated magnetic nanoparticles (Fe₃O₄@SiO₂@Pr-PABA) were prepared. The efficiency of the new Fe₃O₄@SiO₂@Pr-PABA nanoparticles, as a heterogenous nanocatalyst, was examined in the synthesis of biologically-active 2,3-disubstituted-2,3-dihydroquinazolin-4(1H)-one derivatives via one-pot three-component condensation of isatoic anhydride, aromatic aldehydes and aromatic amine on water under reflux conditions. The advantages of this green protocol are low catalyst loading, high to quantitative yields of the favorable products, short reaction times and easy separation and recycle of catalyst.

A simple method for the synthesis of new derivatives of isoindoline-1,3-diones has been developed, which consists in the interaction of N-arylbenzenecarboximidamides with phthalic anhydride in benzene at reflux. It was found that carrying out the reaction without heating leads to the formation of monoacylation products - phthalic acid amides. The structure of the isolated substances was proved using ¹H and ¹³C NMR spectroscopy. Acute toxicity and biological activity in silico was studied for all the obtained compounds using the online programs GUSAR and PASS. For 2-(phenyl(phenylimino)methyl)isoindoline-1,3-dione and 2-((phenyl(phenylimino)methyl)carbamoyl)benzoic acid, an acute toxicity and biological activity in vivo was studied in laboratory mice. It was shown that the results of in silico and in vivo methods are comparable and indicate the low toxicity of the obtained compounds. It was revealed that 2-(phenyl(phenylimino)methyl)isoindoline-1,3-dione has a high analgesic activity, 1.6 times higher than the activity of the reference drug metamizole sodium.

Asymmetric transfer hydrogenation (ATH) of ketones using ([(arene)Ru(TsDPEN)Cl]-type catalysts is now a well-established method for the enantioselective synthesis of alcohols. In most cases, formic acid / triethylamine azeotrope (FA:TEA, 5:2) is used as the hydrogen source. ATH of some simple ketones such as, acetophenone and benzophenone derivatives, using Noyori-Ikariya catalysts has been reported and often gives the corresponding alcohol products with high enantioselectivities. But the ATH of hindered and challenging ketones is less well studied.

Hence, herein we report the results of two systematic studies. The first is of substrates containing the o-hydroxyphenyl group. ATH was carried out using various catalysts out of which (R,R)-C3-tethered catalyst was found to be the most active. The enantioselectivity is influenced by a combination of steric and electronic factors. We demonstrate how the correct choice of substituents can be used to deliver products with very high enantiomeric excess, including examples that would otherwise be very difficult to access by other methods. The directing effect of the o-OH group can provide the products with high enantioselectivity. The methodology was applied to the synthesis if challenging targets, including a sphingosine 1-phosphate receptor inhibitor. In another application, the ATH of a range of ketones flanked by a combination of an aromatic and a heterocyclic ring (furan, thiophene, N-methylimidazole) was also studied. The reduction enantioselectivity was high (up to 99% ee) in cases where the aromatic ring contained an ortho-substituent.

Among analytical methods that can be useful for detecting nanomaterials in watery samples¹, fluorescence-based sensing remains one of the most promising approaches due to its simple solution assay processing, low cost, rapid response and high sensitivity, as well as its high selectivity through molecular binding design.

With the aim of investigating the development of an easily synthesized dansyl-based fluorescent probe for detecting heavy metal-based nanomaterials in aqueous solution, we have designed a Schiff base ligand H2L. This derives from the reaction of 4-formyl-3- hydroxybenzoic acid with N-(2-aminobenzyl)-5- (dimethylamino)naphthalene-1-sulfonamide. H2L incorporates a suitable O,N-binding do- main that can bind heavy metal ions at the surface of the particles.

H₂L can be obtained in a quick two-step synthesis. In the first step, 2‑(aminomethyl)aniline reacts selectively through the aminomethyl group with dansyl chloride to form N-(2-aminobenzyl)-5-(dimethylamino)naphthalene-1-sulfonamide. Subsequent nucleophilic addition of N-(2-aminobenzyl)-5-(dimethylamino)naphthalene-1-sulfonamide to 4-formyl-3-hydroxybenzoic acid yields the desired Schiff base ligand H₂L.

The obtaining of H₂L has been demonstrated using IR and NMR spectroscopies. The IR spectrum of H₂L shows unequivocally the presence of a new strong sharp band at about 1613 cm^-1, which is attributable to the formation of the imino group. The most remarkable observation in the ¹H NMR spectrum of H₂L is the presence of imine (singlet) proton at about 8.66 ppm and the disappearance at 4.83 ppm of the amino group of N-(2-aminobenzyl)-5-(dimethylamino)naphthalene-1-sulfonamide. This is a clear evidence of the condensation of N-(2-aminobenzyl)-5-(dimethylamino)naphthalene-1-sulfonamide with 4-formyl-3-hydroxybenzoic acid yielding the desired Schiff base ligand H₂L.

The aim of the research is the development of an one-pot method for the synthesis of biologically active compounds – lignans. For this purpose the ansa-zirconocenes of various structures were tested as the catalysts of the allylbenzene cyclometalation with ethylaluminum dichloride (EtAlCl₂) and Mg. The effect of organophosphorus compounds hexamethylphosphoramide (HMPA) and triphenylphosphine (PPh₃) on the chemo- and regioselectivity of the reaction was studied. It was shown that the structure of the η⁵-ligand at the Zr atom significantly affects the activity of the system, and the presence of HMPA increases the yield of cyclometalation products up to 77%. The reaction proceeds with the formation of regioisomers of 3,4-dibenzyl- and 2,4-dibenzyl-substituted alumolanes with a ratio (1-2):1, which hydrolysis provides corresponding dibenzylbutane and 9,8'-neo- lignans.