Journal of the Chilean Chemical Society

CHEMICAL CHARACTERIZATION AND BIOLOGICAL ACTIVITY OF POPULATIONS OF VALERIANA CARNOSA SM (CAPRIFOLIACEAE) DISTRIBUTED IN THE SOUTH-CENTRAL ANDES

2022-03-15T12:02:13+00:00

Valeriana carnosa SM (Caprifoliaceae), especie nativa de Chile, se distribuye desde la Región del Maule hasta Tierra del Fuego. Los rizomas y raíces se han utilizado para tratar diferentes enfermedades en forma de infusión, principalmente debido al amplio espectro de compuestos químicos con preocupación biológica. Esta investigación consistió en realizar una caracterización química y evaluación de la actividad antioxidante de V. carnosaen poblaciones naturales distribuidas en la zona centro-sur de Chile. La caracterización de los extractos se realizó mediante GC-MS, mostrando que los extractos de rizoma tanto del Parque Nacional Laguna del Laja como de la Reserva Nacional Malalcahuello mostraron un mayor porcentaje de sesquiterpenos, ácidos grasos y alcanos. Por otro lado, los extractos de hojas para el sitio Antuco presentaron mayor abundancia de alcanos y ácidos grasos y para Malalcahuello, alcanos y fitoesteroles. Se demostraron diferencias significativas en los extractos de rizoma según los valores de IC ₅₀ (157,6 y 154,8 µg / ml) en ambos sitios, sin embargo, para los extractos de hojas, Antuco presentó una IC ₅₀ mayor _.(450,33 µg / ml). ABTS, mostró que Antuco presentó una mayor actividad para ambos extractos, y la misma tendencia se demostró en el contenido de polifenoles, evaluados por el método Folin-Ciocalteu. En conclusión, la distribución de la especie e, indirectamente, las condiciones del sitio se consideran relevantes en esta investigación, mostrando una incidencia directa sobre la actividad biológica y perfil químico de V. carnosa.

REMOVAL OF COPPER IONS FROM AQUEOUS SOLUTIONS BY USING RESINS FROM PINUS RADIATA BARK RESINS

2022-03-15T12:02:44+00:00

A large amount of copper ions are released into the environment, which significantly affects water resources. The reduction of copper contaminants and the potential reutilization of these ions are important issues for environmental and human health. Resin based on Pinus radiata tannin and its derivatives obtained via chemical modifications with three cyclic anhydrides (maleic, citraconic, and itaconic) adsorbed Cu(II) from aqueous solutions. The effect of the pH on the adsorption, desorption, and maximum adsorption capacity for Cu(II) solutions was studied.The adsorption depends largely on the pH of the solution, and the highest adsorption was observed at pH 3. Modified tannins showed lower maximum adsorption values than the original tannin. However, tannins modified with maleic and citraconic anhydrides presented larger values than the unmodified tannin under high ion concentrations. The resin showed a Cu(II) adsorption capacity of approximately 55 mmol g^-1 and a desorption capacity higher55%, hence, it represents a good alternative for future use in the treatment of contaminated water.

POLY(4-VINYLBENZYL) TRIMETHYLAMMONIUM CHLORIDE-CO-(4-VINYLBENZYL)-N-METHYL-D-GLUCAMINE) COPOLYMER WITH REMOVAL PROPERTIES FOR VANADIUM (V) AND MOLYBDENIUM(VI). ADSORPTION ISOTHERM STUDY

2022-03-15T12:03:32+00:00

It was studied the removal properties of poly(4-vinylbenzyl) trimethylammonium chloride–co-(4-vinylbenzyl)-N-methyl-D-glucamine) P(ClVBTA-co-VBNMDG) ion exchange resin towards vanadium (V) and molybdenum (VI), and compared with commercial resin Amberlite IRA-743 which contains the same functional group. The resin was characterized by FT-IR spectroscopy and SEM. Parameters like water adsorption capacity, effect of the pH, maximum retention capacity of the metal ions, elution, regeneration, selectivity, interferents effect, adsorption time, and adsorption isotherms were studied. All the studies were carried out by Batch equilibrium procedure. Thermodynamic parameters such as enthalpy, entropy, and free energy were calculated. The P(ClVBTA-co-VBNMDG) resin showed higher capacity to remove V(V) and Mo(VI) from water solution than that Amberlite IRA-743 commercial resin. The higher capacity displayed by P(VBNMDG) resin was attributed to the higher degree of swelling and the stronger active functional groups.

AN IMPROVED SYNTHESIS OF P-PHENYLENE-BRIDGED METHYLATED BINUCLEAR FERROCENE

2022-03-15T12:09:20+00:00

This contribution describes an updated synthetic route along with full characterization of [{CpFe}₂-p-Ph’] with p-Ph’: p-Bis{2,3,4,5-tetramethylcyclopentadienyl}benzene). The complex reported here was characterized by ¹H and ¹³C NMR, elemental analysis, the X-ray crystal structure, and Mössbauer spectroscopy. From the crystallographic analysis, it was found that both {CpFe} fragments are coordinated to opposite sites of the p-Ph’ ligand. In addition, the analysis through of ¹H and ¹³C NMR spectroscopy, confirm that the synthesis and yield of just one isomer of this compound.

EVALUATION OF CYTOTOXIC EFFECT AGAINST TUMOUR CELLS OF THE ACIDIC POLYSACCHARIDES OF THE FUNGUS NOTHOPHELLINUS ANDINOPATAGONICUS

2022-03-14T16:24:04+00:00

Fungal polysaccharides possess an important bioactive potential, including antioxidant and anticarcinogenic activity. The aim of this work was to determine the antioxidant activity and cytotoxicity against tumour and non-tumour cell lines acidic polysaccharides (NAAPs) of the fungus Nothophellinus andinopatagonicus. The effect of NAAPs on tumour cells lines was evaluated by MTT assay and flow cytometry. The analyses determined that glucose was the most abundant monomer and IR spectrum showed the typical peaks of β-glucans in the NAAPs. The cell viability assays revealed significant activity of NAAPs against HL-60, HCT-116 and MCF-7 tumour cell lines (IC₅₀ = 767,16 µg mL^-1, 1256 µg mL^-1 and 4241,7 µg mL^-1, respectively); but a much lower cytotoxicity against the non-tumour cell line HGF-1 (outside the range of the highest concentration tested (>10 mg mL^-1)). NAAPs affected the cell cycle of HL-60 tumour cells, increasing the percentage of cells in the sub G1 phase and reducing it in the S/G2/M phases. Moreover, low concentrations of NAAPs also showed an effective cytotoxic activity against tumour cell lines while the non-tumour cell line was unaffected, maintaining a viability close to 100%. The antioxidant activity of the highest NAAPs concentration tested was 6.24% and 4.63%, for DPPH and ABTS method, respectively.

PHYTOCHEMICAL PROFILE, ANTIOXIDANT AND ANTIDIABETIC POTENTIAL OF ESSENTIAL OIL FROM FRESH AND DRIED LEAVES OF EUCALYPTUS GLOBULUS

2022-03-15T12:43:39+00:00

Pathogenesis of type 2 diabetes has been linked to oxidative stress. Synthetic drugs in use for the management of the stress and type 2 diabetes are expensive and their usage are associated with side effects. Some essential oils exhibited antioxidant and antidiabetic properties devoid of the effects. Their activities are attributed to the type of phytochemicals whose presence in the oils of the fresh and dried samples are determined by environmental factors. This study therefore aimed at monitoring the effect of air-drying at ambient temperature on the phytochemical profile, antidiabetic and antioxidant potentials of leaf essential oils of E.globulus. To achieve this, 500 g of fresh and dried leaves of E. globuluswere separately pulverized and hydrodistilled for three hours. The leaves yielded oils in the range of 0.22–0.55% (w/w). GC and GC–MS analyses of the oils revealed predominance of α-phellandrene (4.6–10.5%), D-limonene (18.5%) , β-myrcene (20.8%), m-cymene (5.0-29.8%), terpinen-4-ol (0.4-4.7%), globulol (3.1-10.5%) and spathulenol (4.9-18.8%). The antioxidant activity of the oils was determined by DPPH and FRAP assays using ascorbic acid as standard. α-Amylase and α-glucosidase inhibitory assays were used to determine the antidiabetic potential of the oils using acarbose as standard. The oils exhibited antioxidant and antidiabetic activities that compared favourably with the standards. Meanwhile, the oil obtained from the leaves air-dried for three days showed the highest activities with competitive mode of α-amylase and α-glucosidase inhibitions. The oil could serve as alternative for the management of oxidative stress and type 2 diabetes.

EFFECT OF TEMPERATURE AND CONTENT OF CHLORURATED SALT OF Cu(II), Mn(II) OR Al(III) ON THE DENSITY OF ACIDIFIED SEAWATER AND WATER MIXES SAMPLES

2022-03-15T12:44:23+00:00

The relationship between the density of seawater and acidified mixtures samples in the presence of up to a maximum concentrations of 0.18 m for Cu(II), 0.34 m for Mn(II) or 0.6 m for Al(III), in selected temperatures used in the copper leaching process (283.15 - 313.15 K), showed a positive linear behavior with salinity and cation concentration.

The influence of temperature on the density rate changes was similar when comparing the three solutes in acidified solutions of different salinity. The effect of temperature on the change in density did not exceed 1% and by concentration, the greatest influence was due to Al(III) with 5.43%, in agreement with its greater relative quantity.

The data obtained, using a vibrating tube density meter, were used to analyze and correlate to the Apelblat equation that was favorably applied to calculate the isobaric expansibility coefficient. The temperature had an influence on the isobaric expansibility coefficient values, suggesting a making interaction effect due to majority anions present in the seawater and mixture samples (Cl^- > SO₄^-2), and a breaking interaction effect when the cations Cu(II), Mn(II) or Al(III) were added.

NEW CHITOSAN-BASED CHEMO PHARMACEUTICAL DELIVERY SYSTEMS FOR TUMOR CANCER TREATMENT: SHORT-REVIEW

2022-03-15T12:45:04+00:00

The aim of this review is to provide an overview of the delivery systems of chitosan-based chemotherapy agents that have been developed for the treatment of tumor cancer. Cancer treatment is a challenge that has always provided opportunities in different areas of study, due to its very complexity. Innovative options to make chemotherapy an effective treatment by targeting drugs to cancer cells through different modifications in delivery systems are being investigated. Chitosan, a biopolymer that is obtained from the partial deacetylation of chitin (the second most abundant biopolymer on earth) and is present in the exoskeleton of crustaceans, some insects, and also in the cell wall of some fungi. Chitosan has specific characteristics of solubility, functional groups in its structure, crosslinking power, affinity with other materials, biocompatibility, biodegradability, muco adhesiveness, provides bioavailability of the chemotherapeutic agent on cancer cells, without harming healthy cells. This document compiles some interesting studies on the use of chitosan in conjugation with other agents and safe materials for use in biomedicine, for the design, characterization, and development of new transport systems for chemotherapeutic agents, increasing the efficacy of this therapy in cancer treatment tumors.

A REVIEW OF BIODIESEL PRODUCTION FROM NON-EDIBLE RAW MATERIALS USING THE TRANSESTERIFICATION PROCESS WITH A FOCUS ON INFLUENCE OF FEEDSTOCK COMPOSITION AND FREE FATTY ACIDS

2022-03-21T19:45:57+00:00

The main resources needed for an alternative fuel are availability and renewability, that is, less dependence on restricted raw materials accompanied by no or less pollution. Due to being eco-friendly and non-toxic to nature, biodiesel is attracting more and more interest. Biodiesel has many important technical advantages compared to petroleum diesel, such as inherent lubricity, low toxicity, derivation of renewable and domestic raw materials, biodegradability, insignificant sulfur content, and lower exhaust emissions. However, they have some important disadvantages that include the high cost of the raw material, lower storage and oxidative stability, lower volumetric energy content, lower low-temperature operability, and in some cases, higher NOx exhaust emissions. One of the major challenge obstacles is the high cost of refined vegetable oil as raw material, which consists of almost 70% of the total production costs. Therefore, in order to reduce the cost of biodiesel, non-edible sources such as residual cooking oil (WCO), algae oil, non-edible vegetable oil, and residual fats are commonly used for the production of biodiesel due to its low cost and don't affect the food chain. The most common method used in the production of biodiesel is the transesterification of vegetable oils and animal fats. Production and process are influenced by several factors, such as temperature and reaction time, the molar ratio of alcohol to oil, and type and concentration of catalyst. Therefore, this review focuses on the recent discovery of the transesterification of inedible sources for biodiesel, the influence of the composition of the raw material on the quality of biodiesel, and the possible solutions to its disadvantages for the production of biodiesel.

CONJUGATED FATTY ACIDS (CFAS) PRODUCTION VIA VARIOUS BACTERIAL STRAINS AND THEIR APPLICATIONS. A REVIEW

2022-03-14T16:24:05+00:00

Conjugated fatty acids (CFAs) mainly consists of Conjugated linoleic acids (CLAs) and conjugated linolenic acids (CLNAs). CFAs received significant importance because of their anti-carcinogenic, anti-obesity, anti-diabetic, lipid/ energy metabolism modulatory effects and some other health promoting properties. Though, their concentration in food stuff is inadequate for any therapeutic application to be implemented. For a biotechnological perspective, microbial production of these CFAs has been extensively explored as an alternative and various bacterial strains of Propionbacterium, Lactobacillus and Bifidobacterium have shown promising results. This review will amass and recap available data concerning CLA and CLNA production by various bacterial strains via various enzymatic reaction behind all the processes. Numerous studies on CFA biochemical pathways are important to understand and discourse the metabolic mechanisms behind this process showing all the gene products that could be involved in the production. Among these bacterial strains few have shown the modulation of lipid metabolism in-vivo, further research should be focused on this topic which would help us to understand the role of gut microbiota on human health and future foods sustainability.