A comprehensive analysis of the conformational space of the three most abundant naturally occurring methoxylated anthocyanidins -peonidin petunidin and malvidin- as well as their frontier molecular orbitals (HOMO-LUMO) was performed for the first time to explain bioactivities of interest such as antioxidant and antimutagenic activities.

Planar (P) and non-planar (Z) conformers were analyzed in vacuum and in various solvents (using polarizable continuum model; PCM) including acetic acid methanol and water at the B3LYP/6-311++G** level of theory. Boltzmann averages were also calculated thereby achieving the quantitative contribution of each conformation to the total population. Physical properties such as dipole moment and polarizability were also evaluated for each conformer and the entire conformational space.

Thirty-five new conformers were reported for peonidin thirty-four for petunidin and nineteen for malvidin. Correct characterization of the whole conformational space for these compounds demonstrated the coexistence of positively charged quinoidal structures together with other resonance structures. Solvent polarity incorporation of donor groups into ring B together with the percentage contribution of P and Z conformers within the conformational space modified the antioxidant activity of these compounds. The percentage atom contributions to HOMO were appropriate to demonstrate antimutagenic activity as enzyme inhibitors as well as the steric and electrostatic requirements to form the pharmacophore.

Peonidin was the strongest antioxidant anthocyanidin and malvidin was the anthocyanidin with the best antimutagenic activity. The methodology proved to be a useful tool to explain specific bioactivities in anthocyanins and related flavonoid compounds.

Electron Paramagnetic Resonance (EPR) also known as Electron Spin Resonance (ESR) is a powerful nondestructive and nonintrusive characterization technique to evaluate unpaired electrons in paramagnetic substances. Unpaired electrons are found in free radicals and transition metals and are the main source of physical-chemistry changes in inorganic and organic substances. Thus EPR characterization has a wide range of applicability in catalysis photonics electrochemistry biology medicine semiconductors biofuels and radiation dosimetry.

However to extract useful data from EPR analysis a set of measurement parameters have to be adjusted. The present study aims to report how an EPR parametrization such as the number of scans modulation amplitude and sweep time are effective in the characterization of europium-thulium co-doped yttria (YET) nanoparticles.

Based on results EPR spectra of YET particles with suitable signal/noise ratio and resolution could be achieved using 10 scans modulation amplitude of 4G and sweep time of 10.2s.

These findings are promising data to advance toward formation of new materials based on rare-earth oxides for radiation dosimetry.

Among the various types of quantum dots Carbon Quantum Dots (CQDs) have emerged as a particularly promising class of nanomaterials. CQDs are characterized by their tunable photoluminescence high chemical stability low toxicity and excellent biocompatibility making them suitable for a wide range of applications including bioimaging sensing drug delivery and energy-related devices. Recent research has focused on enhancing the optical properties of CQDs through doping with rare earth elements which introduces unique photoluminescence properties due to their distinct electronic configurations and energy transitions. Photon upconversion a process where lower-energy photons are absorbed and re-emitted as higher-energy photons is a key area of interest in CQD research. This phenomenon is particularly useful in applications that require high-energy ultraviolet light such as bioimaging and photocatalysis. The ability of CQDs to exhibit photon upconversion alongside their traditional downconversion photoluminescence adds to their versatility and potential for innovative applications. The objective of this study is to synthesize and characterize pure and rare earth-doped Carbon Quantum Dots (CQDs) using a hydrothermal method with gelatin as the precursor. The research aims to investigate the photoluminescent properties of these CQDs with a particular focus on their photon upconversion capabilities and emission stability. By exploring the effects of doping and synthesis conditions on the optical characteristics of CQDs the study seeks to enhance their potential for applications in fields such as bioimaging fluorescent marking solar cell efficiency enhancement and other technologies requiring stable and reliable luminescence. The ultimate goal is to demonstrate the suitability of these synthesized CQDs for various scientific and practical applications contributing to advancements in nanomaterial research and technology.

The hydrothermal bottom-up method for synthesizing Carbon Quantum Dots (CQDs) involves dissolving 0.5 grams of gelatin in 25 mL of doubly deionized water with continuous stirring to create a uniform solution. This solution is then transferred into a 50 mL Teflon-lined autoclave which is placed in a muffle furnace set to 160°C. The mixture undergoes a hydrothermal reaction under controlled heat and pressure for 4 hours converting the gelatin into CQDs. After heating the autoclave is allowed to cool gradually stabilizing the synthesized CQDs with distinctive optoelectronic properties.

Gelatin-based pure and doped Carbon Quantum Dots (CQDs) were synthesized using the hydrothermal method and their photoluminescent and up-conversion properties were studied. Photoluminescence was observed at different excitation frequencies. At an excitation wavelength of 314 nm the emission wavelengths for P-CQD C-CQD and L-CQD were 395 nm 402 nm and 398 nm respectively. For an excitation wavelength of 341 nm the emissions were 402 nm 422 nm and 417 nm. Photon up-conversion was examined using a 420 nm excitation showing emission frequency variations with doping.

The synthesized gelatin-based pure and doped CQDs exhibited distinct photoluminescent and up-conversion properties with emission wavelengths varying according to the excitation frequencies and types of doping. The observed shifts in emission wavelengths especially under up-conversion at 420 nm excitation demonstrate that doping influences the optical behavior of CQDs. This tunability of emission frequencies is particularly promising for frequency conversion applications such as enhancing the spectral absorbance range of solar cells potentially improving their efficiency by enabling better utilization of the solar spectrum.

Our research aims to uncover how solute-solvent and solute-solute interactions behave in aqueous solutions exploring how temperature variations and concentration changes influence these interactions. This can provide deeper insights into the behavior of molecules in different environments potentially leading to applications in fields such as drug delivery chemical reactions and material science.

In the aqueous ternary system the physicochemical interactions between a medically powerful pharmacological molecule and two naturally occurring amino acids were explored. The investigations were performed in a dilute to infinite dilute medium to study the interactions between the solutes and solvent extensively.

The objective of this research is to systematically investigate the nature of solute-solvent and solute-solute interactions in aqueous solutions across a range of temperatures and concentrations. By doing so we aim to elucidate the underlying principles governing these interactions which could contribute to a deeper understanding of solution chemistry. This knowledge is intended to inform the development of more efficient and effective applications in various scientific and industrial fields including drug formulation catalysis and material design.

To characterize and calculate the interactions in the ternary system various models and formulas were considered and applied. Based on various parameters including viscosity-B coefficient apparent molar volume and molar conductance from viscosity density and conductance studies varying temperatures and concentrations were used to elucidate the molecular interactions. To elucidate the interactions between solute with co-solute and with solvent the limiting apparent molar volumes and the experimental slopes derived from the Masson equation and the Viscosity constants A and B obtained via the Jones-Doles equation were examined. To illustrate the structure- breaking/making character of the solutes in the solution Hepler’s method and dB/dT values were applied.

The results indicated that hydrophobic-hydrophobic interaction plays a significant role in the system.

These amino acid interaction models may explain the properties of a variety of physiologically active compounds and the mechanism can be expanded to comprehend the nature of similar systems. Furthermore the research could lead to advancements in areas such as pharmaceutical sciences where controlling solute interactions is crucial for drug delivery systems and in environmental chemistry where understanding pollutant behavior in water is essential for remediation efforts.

Superparamagnetic nanoparticles are widely employed in biomedicine especially in the fields of Magnetic Resonance Imaging (MRI) targeted medication delivery and hyperthermia therapy. Drugs or biomolecules can be used to functionalize SPIONs and an external magnetic field can be used to direct them to specific areas within the body. This allows for more focused medication administration with fewer systemic adverse effects. In chemotherapy adjunct therapy is found to be more beneficial and the use of vitamins and minerals as an add-on drug may improve tolerance. In this study soft hydrolysis of iron silica core-shell nanoparticles was achieved. The aim was to to study the loading and unloading of curcumin using Fe3O4-silane core-shell nanoparticles. Additionally Vitamin C was utilized as an add-on drug and DNA was cleavaged in the presence of Vitamin C whose effects were also studied.

The curcumin-loaded Fe2O4-silica magnetic nanoparticles (CLFS) were prepared and characterized using various methods. In particular the nanoparticles were characterised using SEM and XRD spectral techniques. The loading and unloading of curcumin were studied using absorption spectral techniques. The interaction of DNA was studied using emission CD electrochemical and gel electrophoresis techniques.

The loading capacity of curcumin was found to be 6.3 higher than that of commercial samples. A significant release of curcumin was observed using absorption spectroscopy after sonication. The DNA binding of CLFS with CT-DNA was confirmed using absorption emission CD and electrochemical studies.

The effective binding was established using these studies. The increase in the curcumin bioavailability was due to the loading of curcumin in CLFS. The efficient binding was established from the absorption emission and CD spectral results. The addition of vitamin C resulted in the breakage of DNA which was demonstrated using gel electrophoresis studies.

The ultimate goal of this novel strategy is to encapsulate curcumin in magnetic nanoparticles so that it can release the compound continuously over a period of seventy hours at a pH that is similar to physiological conditions. In the future CLFS may be used to treat cancer because it cleaves plasmid DNA into linear form when combined with vitamin C an add-on medication.