Mo(VI) complex catalysed synthesis of sulfones and their modification for anti-HIV activities

Glucoconjugated Dinuclear Copper(II) Complex: An Efficient Catalyst for Stereoselective Synthesis of Trisubstituted Propargylamines via Solvent-free A3 Coupling Reaction

Development of catalytic systems using nontoxic natural precursors is the need of the era, and along this line, we have synthesized a new D-glucose derived ligand (4,6-O-ethylidene-N-(2-hydroxy-4-(octyloxy)benzylidene)-β-D-glucopyranosylamine) and its dinuclear copper(II) complex. The molecular structure of the complex has been established by single-crystal X-ray diffraction studies and detailed noncovalent intermolecular interactions present in it have been explored by Hirshfeld surface analysis. Further, the complex has been used as a catalyst in the enantioselective (87-99 % ee) synthesis of propargylamines in good to excellent yield (82-95 %) via aldehyde-amines-alkynes (A3) coupling reaction under solvent-free condition. The formation of aminal intermediate during the reaction has been confirmed by 1H-NMR and single-crystal X-ray diffraction studies. The catalytic system is reusable without any appreciable loss in the enantioselectivity or product yield.

Late-Stage Fluorination of Tyrosine Residues in Antiviral Protein Cyanovirin-N

The applications of fluorinated molecules in chemical biology are rapidly expanding driven by the unique properties of C-F bonds, leading to increased interest in methodologies for controlled introduction of this atom. In this study, we present the first method for late-stage fluorination of tyrosine residues in proteins. Our results demonstrate that electrophilic fluorination using Selectfluor, a stable and non-toxic reagent, offers a straightforward and cost-effective method for labeling Cyanovirin-N (CVN), a 101-amino-acid lectin with effective antiviral activity. Uni- and bidimensional 1H, 13C and 19F NMR analyses, along with mass spectrometry, revealed chemoselective fluorination of the three tyrosine residues in CVN without affecting its overall structure or mannose-binding affinity. Additionally, we observed that other aromatic amino acids, such as tryptophan, phenylalanine, and histidine, are not fluorinated using this method. These findings advance our understanding of protein fluorination and its applications in studying structure, dynamics, and interactions, as well as other biological utilities.

Synthesis, Characterization, and Biological Evaluation of Novel N-{4-[(4-Bromophenyl)sulfonyl]benzoyl}-L-valine Derivatives

In this article, we present the design and synthesis of novel compounds, containing in their molecules an L-valine residue and a 4-[(4-bromophenyl)sulfonyl]phenyl moiety, which belong to N-acyl-α-amino acids, 4H-1,3-oxazol-5-ones, 2-acylamino ketones, and 1,3-oxazoles chemotypes. The synthesized compounds were characterized through elemental analysis, MS, NMR, UV/VIS, and FTIR spectroscopic techniques, the data obtained are in accordance with the assigned structures. Their purities were verified by reversed-phase HPLC. The new compounds were tested for antimicrobial action against bacterial and fungal strains for antioxidant activity by DPPH, ABTS, and ferric reducing power assays, and for toxicity on freshwater cladoceran Daphnia magna Straus. Furthermore, in silico studies were performed concerning the potential antimicrobial effect and toxicity. The results of antimicrobial activity, antioxidant effect, and toxicity assays, as well as of in silico analysis revealed a promising potential of N-{4-[(4-bromophenyl)sulfonyl]benzoyl}-L-valine and 2-{4-[(4-bromophenyl)sulfonyl]phenyl}-4-isopropyl-4H-1,3-oxazol-5-one for developing novel antimicrobial agents to fight Gram-positive pathogens, and particularly Enterococcus faecium biofilm-associated infections.

Simultaneous dyeing and antibacterial finishing of polypropylene using vinyl sulfone dye under supercritical carbon dioxide

Polypropylene fibres are difficult to dye using commonly used techniques due to the high crystallinity and non-polar aliphatic structure, that lack reactive places for dyes in the molecule. Dyeing PP fabric in scCO₂ with antibacterial dyes merged the dyeing and finishing methods, resulting in a more productive technique in terms of water and energy consumption. Unmodified polypropylene fabric was dyed with 4-[2-[4-(ethenylsulphonyl)phenyl]diazenyl]-N,N-diethylbenzenamine antibacterial dye under scCO₂ medium. The influences of scCO₂ working parameters, such as dye concentration, pressure, dyeing time, and temperature, on fabric dye absorption expressed as color strength were studied. The color strength (K/S) was measured as well as CIELAB color parameters. The results were compared with its water dyeing analogue and it was observed that color strength as well as color depth (L) of the samples dyed in scCO₂ were noticeably better than its water counterpart. In both scCO₂ and water, the fastness properties (washing, rubbing, and light) of the dyed samples were excellent. Antibacterial activity of the dyed polypropylene sample in scCO₂ was estimated and the results indicated good antibacterial efficiency.

Sulfoxide and Sulfone Synthesis via Electrochemical Oxidation of Sulfides

The oxidation of diaryl sulfides and aryl alkyl sulfides to the corresponding sulfoxides and sulfones under electrochemical conditions is reported. Sulfoxides are selectively obtained in good yield under a constant current of 5 mA for 10 h in DMF, while sulfones are formed as the major product under a constant current of 10 or 20 mA for 10 h in MeOH. The oxygen of both the sulfoxide and sulfone function is derived from water.

Platinum complexes inhibit HER-2 enriched and triple-negative breast cancer cells metabolism to suppress growth, stemness and migration by targeting PKM/LDHA and CCND1/BCL2/ATG3 signaling pathways

Triple-negative-breast cancer (TNBC) and HER-2 enriched positive aggressive types of breast cancer and are highly metastatic in nature. Anticancer agents those target TNBC and HER-2 enriched positive breast cancers are considered important in the field of breast cancer research. In search of the effective anticancer agents, we synthesized Pt(II) complexes to target these cancers. Platinum complexes (C1-C8) were prepared in single step by the reaction of commercially available K₂PtCl₄ with the readily prepared ligands (L1-L8). All these compounds were characterized successfully by different spectroscopic and spectrophotometric analyses. Structures of C1, C3 and C8 were characterized by single crystal X-ray analysis that confirmed the exact chelation mode of the SNO-triply coordinated ligand. All these complexes inhibited the in vitro growth of MCF-7 (luminal-like), MDA-MB-231 (TNBC) and SKBR3 (HER-2 enriched) breast cancer cells. C1, C3 and C7 induced cell death and suppressed the clonogenic potential of these cancer cells. Importantly, C1, C3 and C7 showed potentials to suppress cancer stem cells/mammosphere formation and cell migration ability of MDA-MB-231 and SKBR3 breast cancer cells. These complexes also induced cellular senescence in MDA-MB-231 and SKBR3 cells, thus suggesting a cell retardation mechanism. Similarly, these complexes induced DNA damage by activating p-H2AX expression and promoted autophagy via ATG3/LC3B axis activation in MDA-MB-231 and SKBR3 cells. Furthermore, these complexes decreased the expression of oncogenic proteins such as BCL2 and cylin-D1 those are involved in cancer cell survival and cell cycle progression. To further gain insight, we found that C1 and C7 targeted glycolytic pathways by regulating PKM and LDHA expression, which are involved in glycolysis. Moreover, C1 and C7 suppressed the formation of ATP production that is required for cancer cell growth. Taken together, the easy synthesis and biological assays results point towards the importance of these complexes in MDA-MB-231 (TNBC) and SKBR3 (HER-2 enriched) breast cancer cells by targeting multiple signaling pathways those are considered important during breast cancer progression. This study produces bases for further deeper in vitro or in vivo study that could lead to the effective breast cancer agents which we are working on.