Keenelynge3712

Two chiral Ru(II) polypyridyl complexes, Δ-[Ru(bpy)2(6-F-dppz)]2+ (Δ-1; bpy = 2,2'-bipyridine, 6-F-dppz = 6-fluorodipyrido[3,2-a2',3'-c]phenazine) and Λ-[Ru(bpy)2(6-F-dppz)]2+ (Λ-1), have been synthesized and characterized as binders for the RNA poly(U)•poly(A)*poly(U) triplex and poly(A)•poly(U) duplex in this work. Analysis of the UV-Vis absorption spectra and fluorescence emission spectra indicates that the binding of intercalating Δ-1 with the triplex and duplex RNA is greater than that of Λ-1, while the binding affinities of the two enantiomers to triplex structure is stronger than that of duplex structure. Fluorescence titrations show that the two enantiomers can act as molecular "light switches" for triple- and double-helical RNA. Thermal denaturation studies revealed that that the two enantiomers are more stable to Watson-Crick base-paired double strand of the triplex than the Hoogsteen base-paired third strand, but their stability and selectivity are different. For Δ-enantiomer, the increase of the thermal stability of the Watson-Crick base-paired duplex (13 °C) is slightly stronger than of the Hoogsteen base-paired strand (10 °C), displaying no obvious selectivity. However, compared to the Hoogsteen base-paired strand (5 °C), the stability of the Λ-enantiomer to the Watson-Crick base-paired duplex (13 °C) is more significant, which has obvious selectivity. The overall increase in viscosity of the RNA-(Λ-1) system and its curve shape are similar to that of the RNA-(Δ-1) system, suggesting that the binding modes of two enantiomers with RNA are intercalation. The obtained results in this work may be useful for understanding the binding differences in chiral Ru(II) polypyridyl complexes toward RNA triplex and duplex.Synthesis and spectroscopic characterization of five ligands ((E)-2-((pyridin-2-ylmethylene)amino)phenol L1, 2-(pyridin-2-yl)benzo[d]thiazole L2, (E)-N-(2-fluorophenyl)-1-(pyridin-2-yl)methanimine L3, (E)-1-(pyridin-2-yl)-N-(p-tolyl)methanimine L4 and (E)-1-(pyridin-2-yl)-N-(thiophen-2-ylmethyl)methanimine L5 along with fifteen silver(I) complexes of L1 - L5, with a general formula [AgL2]+X- (L = Schiff base and X = NO3-, ClO4- or CF3SO3-) is reported. The structures of complexes [Ag(L4)2]NO3, [Ag(L5)2]NO3, [Ag(L3)2]ClO4, [Ag(L4)2]ClO4 and [Ag(L5)2]CF3SO3 were determined unequivocally by single crystal X-ray diffraction analysis. Calf-thymus deoxyribonucleic acid (CT-DNA), bovine serum albumin (BSA) binding studies, antioxidant, and antibacterial studies were performed for all complexes. Complexes [Ag(L2)2]NO3, [Ag(L5)2]NO3, [Ag(L1)2]ClO4 and [Ag(L3)2]ClO4 whose ligands have an OH- and F- as substituents or with a thiophene or thiazole moiety showed better antibacterial activities with lower minimum inhibitory concentration (MIC) values compared to the standard ciprofloxacin, against most of the bacterial strains tested. Similarly, complexes [Ag(L1)2]NO3,[Ag(L2)2]NO3,[Ag(L3)2]NO3 and [Ag(L5)2]NO3 with the NO3- anion, [Ag(L1)2]ClO4 and [Ag(L2)2]ClO4 with ClO4- anion, and [Ag(L5)2]CF3SO3 with CF3SO3- anion showed higher activities for antioxidant studies. Complexes [Ag(L4)2]ClO4 and [Ag(L4)2]CF3SO3 with the Methyl substituent and CF3SO3- as the anion, displayed high antioxidant activities in FRAP (ferric reducing antioxidant power) than the standard ascorbic acid. Spectroscopic studies of all the complexes revealed their moderate to high interaction with calf thymus DNA via an intercalation mode. In addition, the relatively moderate interaction of most of the complexes with BSA was through a static quenching mechanism.An eco-friendly, efficient, and controlled synthesis of gold nanoparticles with application of the aqueous extract of Rosa damascena (Au@RD NPs) without using any other reducing agents was studied. Au@RD NPs of narrow size distribution were characterized by UV-vis and FT-IR spectroscopies, transmission electron microscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, particle size analysis, and zeta potential measurements. In vitro stability experiments revealed that the Au@RD NPs were stable for over a year (pH ~ 3.5), proving a significant stabilizing potential of the aqueous RD extract. The high total content of polyphenols, flavonoids, and reducing sugars along with the powerful antioxidant activity of the RD extract was determined by spectroscopic and analytical methods. Colloids prepared from the purified and lyophilized Au@RD NPs (electrokinetic potential of ca. -33 mV) were stable for at least 24 h under terms similar to physiological conditions (pH = 7.4, PBS). The in vitro cytotoxicity of Au@RD NPs was investigated against peripheral blood mononuclear lymphocytes (PBML), acute promyelocytic leukemia (HL60), and human lung adenocarcinoma (A549). Selective cytotoxicity of Au@RD NPs towards cancer cells (HL60, A549) over normal cells (PBML) in vitro was explicitly demonstrated by viability assays. Comet assay revealed a higher level of DNA damages in cancer cells when compared with normal ones. Apoptotic death in cancer cells was proved by measuring caspases activity. Thus, the developed Au@RD NPs, obtained by the plant-mediated green synthesis, are attractive hybrid materials for the medical applications combining two active components - metal nanoparticles platform and plant-derived metabolites.Alzheimer's disease (AD) is the most common form of dementia, characterized by extracellular protein deposits, comprised primarily of the peptide amyloid-beta (Aβ), are a pathological indicator of the disease. Commonly known as Aβ plaques, these deposits contain a relatively high concentration of metals, making metallotherapeutics uniquely suited to target soluble Aβ, thereby limiting its aggregation and cytotoxicity. Ruthenium-based complexes are promising candidates for advancement, as the complex PMRU20 (2-aminothiazolium [trans-RuCl4(2-aminothiazole)2]) and several thiazole-based derivatives were found to prevent the aggregation of Aβ, with hydrogen-bonding functional groups improving their performance. Further investigation into the impact of the heteroatom in the azole ring on the activity of Ru complexes was achieved through the synthesis and evaluation of a small set of imidazole-based compounds. Fimepinostat The ability of the complexes to prevent the aggregation of Aβ was determined where the same sample was subjected to analysis by three complementary methods ThT fluorescence, dynamic light scattering (DLS), and transmission electron microscopy (TEM).