Journal of the Chilean Chemical Society

Synthesis of Curcumin-ferulic acid conjugate via Steglich esterification and anti-lung cancer activity of against Human non-small lung cancer cells (NSLCC)

2025-01-11T00:35:08+00:00

In the current work, the conjugate of curcumin and ferulic acid (compound 1) was developed and then examined utilizing a battery of biochemical assays to assess its pharmacological effectiveness against lung cancer. The compound 1 was synthesized using steglich esterification in excellent yield and then evaluated for its ability to inhibit the growth of different types of human cancer cells, including cells of the gastric cancer (SGC-7901), breast cancer (MCF7), liver cancer (HepG-2), lung cancer (A549), and human cervical carcinoma (HeLa). It exhibited stronger inhibitory effects on A549 cells compared to the other cell types, indicating its potent anti-lung cancer activity. It induces substantial suppression of many kinases, including EGFR, PI3K, mTOR, and VEGFR2. It exhibited cell cycle suppression of G2/M phase, resulting in a significant rise in apoptosis rate in A549 cells. Compound 1 showed a notable suppression of telomerase activity and a rise in the depolarization of mitochondrial membrane potential in A549 cells. The present study showcased the creation of a curcumin-ferulic acid conjugate (referred to as Compound 1) as a very potent anticancer medication that selectively targets lung cancer cells.

IMPORTANCE OF DEW AS A REMOVER OF ATMOSPHERIC CATIONS AND ANIONS IN AN URBAN AREA OF SANTIAGO, CHILE

2025-01-11T00:35:08+00:00

ABSTRACT

In an urban commune of Santiago, Chile, a monitoring campaign for dew and PM₁₀atmospheric particulate matter was implemented during 2022. The pH, conductivity, cation and anion concentrations of dew water, and the water-soluble fraction of PM₁₀, were analyzed.

In the water-soluble fraction of PM₁₀, the average cation concentrations were: 4.19 µgm³for ammonia; 1.40 µgm^-3 for calcium; 0.46 µgm^-3 for potassium; 0.36 µgm^-3for sodium; and 0.17 µgm^-3 for magnesium. In a decreasing order, concentrations were: NH₄ ˃ Ca ˃ K ˃ Na ˃ Mg ˃ Zn ˃ Ba ˃ Cu ˃ Mn ˃ Al ˃ As ˃ V.

Among anions, the nitrate ion showed concentrations within the 4.49 to 20.09 µgm^-3 range. The concentration of the carbonate ion ranged between 0 and 6.7 µgm^-3 ; the sulphate ion ranged from 2.65 to 6.13 µgm^-3 ; the chloride ion from 2.21 to 3.43 µgm^-3 M; the phosphate ion varied between 2.08 and 2.33 µgm^-3 ; the nitrite ion between 1.21 and 1.33 µgm^-3 ; and the fluoride ion between 0.14 and 0.18.

Simultaneously, 60 water dew events were collected during working days, with a total volume of 6465 mL, and 20 events on weekends. This volume was similar to the total level of rainfall in Santiago during 2022 (8217mL). In the dew water, the mean pH was 7.47, and the mean concentrations were: ammonia:13300 µgL^-1, calcium: 12040 µgL^-1 , potassium: 2600 µgL^-1 , sodium 1530 µgL^-1 , magnesium: 669 µgL^-1 , zinc: 65 µgL^-1, manganese: 50 µgL^-1 , and copper:19 µgL^-1. Among anions, mean concentration values were: chlorides: 8720 µgL^-1 ; sulphates: 28938 µgL^-1; nitrates: 32538 µgL^-1: nitrites: 7556 µgL^-1; and carbonates: 14540 µgL^-1.

Simple linear correlations between cations and anions present in dew water and PM₁₀ showed values of 0.788 and 0.81, indicating a key removing role from the dew water in this city. In Santiago, dew water has a cleansing or removal effect as important as that of rain water

Homobimetallic Ferrocene derived from 1,4-phenylenebis(1H-1,2,3-triazole-4,1-diyl))diphenol as burning rate catalyst

2025-01-11T00:35:08+00:00

To comprehend the synergistic catalytic effect on the thermal decomposition of ammonium perchlorate (AP) when two ferrocene (Fc) fragments are in the same molecule linked by the ligand 4,4'-(1,4-phenylenebis(1H-1,2,3)-triazol-4,1-diyl))diphenol (1) was synthesized a bimetallic ferrocene compound (2), and compared with other homo- and monobimetallic ferrocene compounds already reported, as a potential burning rate catalyst. We conducted a differential scanning calorimetry (DSC) analysis of compound (2), which showed a decrease the high-temperature decomposition (HTD) of Ammonium Perchlorate (AP) to 379 ºC. Our results suggest that the ferrocene is a suitable and competitive alternative to be used as an enhancer of solid composite propellants.

DETERMINATION OF pKa AND pKb FROM ELECTRONIC PROPERTIES DERIVED FROM CONCEPTUAL DENSITY FUNCTIONAL THEORY (cDFT)

2025-01-11T00:35:08+00:00

In the present work we apply a semiempirical method capable of calculating the pka and pkb values of a series of organic acids and bases through their electronic properties. This multilinear model, analogous to the one introduced by Kamlet-Taft, relates acid-base properties such as HBA and HBD to the regional electrophilicity and nucleophilicity derived from cDFT. To test the model, it was applied to a series of mono and dicarboxylic acids, as well as aliphatic/cyclic and heterocyclic amines, showing us that the model is only functional when the series of compounds present similar characteristics such as functional groups. Based on the regionalization of the electrophilicity and nucleophilicity, it can be observed that the acid-base characteristics are not exclusive to limited regions of the molecules, but that these present a bifunctional character that shifts to the relative characteristics of acid and/or base according to the global distribution of the electronic density.

Synthesis, Characterization, Crystal structures and Corrosion Inhibition Capabilities of The New (1H-Benzotriazol-2-yl)methyl Acetate and Their Analogs

2025-01-11T00:35:08+00:00

The products of 1H-benzotriazole-1-methanol 1 O-acetylation, and their corrosion inhibition capabilities are reported. The O-acetylation of 1 led to the formation of 1-acetyl-1H-benzotriazole 4 as the major product and minor quantities of the O-acetylated isomeric acetates 2 and 3. Molecular structures were determined by NMR Spectroscopy, HRMS, and Single crystal X-ray diffraction. STM D1275-06 test was used to assess the corrosion inhibition capabilities. Compound 1 was the most active inhibitor. Substitution at N2 position is not recommended when looking for inhibition capabilities, the electron attracting capacity and the substituent’s size are important for an effective interaction with the copper surface.

ONE-POT GREEN SYNTHESIS OF FLUORESCENT-QUANTUM CARBON DOTS FROM AVOCADO PEELS AND EVALUATION OF ITS ANTIMICROBIAL PROPETIES

2025-01-11T00:35:08+00:00

In this work, avocado peel was chosen as a low-value waste that could be used as a carbon source to synthesize carbon dots (APCQDs). To obtain it, the hydrothermal method was used in the absence of co-doping agents. The synthesis was carried out for 6 hours at 250 ºC. After purification by dialysis and lyophilization, CQDs that exhibited intense blue fluorescence (emission at 378 nm) were obtained. Field emission scanning electron microscopy (FESEM), evidence the spherical morphology of carbon dots within nanometer range. HPLC analysis and separation showed excellent separation even in columns with low porosity, indicating a separation mechanism where polarity predominates as the property that governs the separation. It is highlighted that avocado peel CQDs have potent antimicrobial activity against the pathogens Listeria monocytogenes ATCC 7644, Escherichia coli ATCC 11775, Staphylococcus aureus ATCC 9144, and Salmonella enterica ATCC 13076. The antioxidant effect was also evidenced in the DPPH and ORAC-FL. The synthesis method for APCQDs could be easily scaled up for gram scale synthesis of carbon quantum dots.

STUDY OF THE ADSORPTION-DESORPTION PROCESS OF THE METALS: Cu, Mn, Pb and Zn IN VOLCANIC SOILS.

2025-01-11T00:35:08+00:00

ABSTRACT

The study of the processes of adsorption – desorption of metallic trace elements or heavy metals in soils is crucial for the proposal of effective strategies for mitigation, reduction or elimination of these in natural systems.

This work presents a study of the processes of adsorption and/desorption of Cu, Mn, Pb and Zn in two Chilean soils: Alhué (VI Region, Chile) and Nueva Braunau (X Region, Chile), both of volcanic origin and agricultural use.

The soil samples studied were dried and sieved (< 2 mm or < 0.63 mm). The physicochemical characterization: pH, CE, MO, COT, N, P, CIC and texture was performed using described methods. The total fraction of each metal was obtained by microwave digestion with HNO₃ and HCl. The contact time needed to reach equilibrium was determined by leaving the soil with the metal solution at different times (3, 6, 12, 24, 48 and 72 hours). The adsorption process was performed by a batch experiment, mixing different aliquots of metal solution with balancing solution (KNO₃) 0.1 molL^-1. Desorption was made from the 50/50 metal/balancing solution. The metals in the different soil samples and the total fraction in the soil were determined by AAS.

The distribution of the total fraction of metals in decreasing order is in Alhué soil: Mn > Pb > Cu > Zn and in Nueva Braunau soil: Mn > Pb > Zn > Cu. It was determined that the contact time at which metals reach equilibrium is 48 hours for both soils, fitting appropriately with Elovich's model.

The decreasing order of adsorption in the Alhué soil is: Cu > Zn > Pb > Mn and in the Nueva Braunau soil: Cu > Pb > Zn > Mn.

The determination of the type of adsorption was made through the application of adsorption models of Langmuir and Freundlich. Cu adjusted according to the Langmuir model on both soils. Cu and Zn conformed to Freunlich's model.

The desorption results are: Alhué soil: Pb > Mn > Zn > Cu and Nueva Braunau soil: Mn > Pb > Zn > Cu.

The negative ΔG° (Gibbs free energy change) values obtained in the presents study indicate that the adsorption of metals onto soil samples is a spontaneous process and that the adsorption was an exothermic process excep for Mn in both soils.

Antioxidant activity and phytoactive compounds related to biological effects present in native southern Chilean plants: A review.

2025-01-11T00:35:08+00:00

Studies carried out in different native Chilean plants demonstrate that compounds found in both fruits and leaves have the capacity to decrease oxidative cellular damage in humans, thus contributing to the prevention of chronic illnesses such as diabetes, cancer, and arterial hypertension. Information on native Chilean medicinal plants was extracted from the Scopus, Science Direct, Google Scholar, and PubMed databases. Plants with relevant antioxidant activity were selected based on their chemical compounds and their use as native-flora research materials in Chile. Provitamin A, carotenoids and vitamins C and E are the main compounds found in the studied species. Several analyses also show the presence of polyphenolic and alkaloid compounds with proven capacity to increase antioxidant activity. Therefore, such native species should be of interest for the food, cosmetic, and pharmaceutical industries, as safer natural antioxidant compounds are crucial for the prevention of human illnesses and for replacing the synthetic antioxidants currently in use (BHT, BHA).

The present review aims to provide up-to-date information on the traditional uses of native plants in popular medicine, and to present evidence concerning the antioxidant activity of the studied plant species and their relationship with the active principles found.

Comparison of Arsenic Speciation Techniques: Focus on Chemical and Electrochemical Methods

2025-01-11T00:35:09+00:00

Traditional chemical methods, such as HPLC and AAS, are sensitive and selective for arsenic speciation but require complex sample preparation and are costly. In contrast, electrochemical methods, like voltammetry, offer a faster, more sensitive, and cost-effective analysis with a simpler sample preparation, highlighting their sample size and portability. The choice between both approaches depends on the specific needs of the analysis and the available resources.