Agobardo Cárdenas-Chaparro’s research while affiliated with Pedagogical and Technological University of Colombia and other places

Aims: Perform the synthesis of novel fluoro phenyl triazoles via click chemistry with or without microwave irradiation and their evaluation as anti-proliferative agents in SiHa cells Background: Triazoles are heterocyclic compounds containing a five-member ring with two carbon and three nitrogen atoms. They are of great importance since many of them have shown to have biological activity as antifungal, antiviral, antibacterial, anti-HIV, anti-tuberculosis, vasodilator, and anticancer agents. Objective: Synthesize novel fluoro phenyl triazoles via click chemistry and evaluate their anti-proliferative activity Method: First, several fluorophenyl azides were prepared. Reacting these aryl azides with phenylacetylene in the presence of Cu(I) catalyst, the corresponding fluoro phenyl triazoles were obtained by two methodologies, stirring at room temperature and under microwave irradiation at 40 ºC. In addition, their antiproliferative activity was evaluated in cervical cancer SiHa cells Result: Fluoro phenyl triazoles were obtained within minutes by means of microwave irradiation. The compound 3f, containing two fluorine atoms next to the carbon connected to the triazole ring, was the most potent among the fluoro phenyl triazoles tested in this study. Interestingly, the addition of a fluorine atom to the phenyl triazole structure in a specific site increases its antiproliferative effect as compared to parent phenyl triazole 3a without a fluorine atom. Conclusion: Several fluoro phenyl triazoles were obtained by reacting fluoro phenyl azides with phenylacetylene in the presence of copper sulphate, sodium ascorbate and phenanthroline. Preparation of these triazoles with MW irradiation represents a better methodology since they are obtained within minutes and higher yields of cleaner compounds are obtained. In terms of biological studies, the proximity between fluorine atom and triazole ring increases its biological activity.

Z‐bixin is the main metabolite contained in Achiote, which is widely used as a food condiment and pigment. Z‐bixin plays an important role in photosynthesis. It is used to develop artificial solar cells and scavenge radical oxygen and nitrogen species. In this work, the photochemistry of Z‐bixin with solar irradiation and lamps at 365 and 410 nm was determined in solution. The ultraviolet‐visible spectroscopy (UV‐Vis) and Ultra High Performance Liquid Chromatography (UHPLC) analysis showed that elaidinization of Z‐bixin to E‐bixin can be reached under radiation. This is in accordance with the computational evaluation that indicates that the mechanism consists of three bond rotations with an energy requirement of 5.43 and 5.23 kcal/mol for the first and second steps and no energy barriers to the last step. After elaidinization, total degradation was observed through a cascade reaction that generated CO, CO2, H2CO, and HCl.

Chagas and leishmaniasis are two neglected diseases considered as public health problems worldwide, for which there is no effective, low-cost, and low-toxicity treatment for the host. Naphthoquinones are ligands with redox properties involved in oxidative biological processes with a wide variety of activities, including antiparasitic. In this work, in silico methods of quantitative structure–activity relationship (QSAR), molecular docking, and calculation of ADME (absorption, distribution, metabolism, and excretion) properties were used to evaluate naphthoquinone derivatives with unknown antiprotozoal activity. QSAR models were developed for predicting antiparasitic activity against Trypanosoma cruzi, Leishmania amazonensis, and Leishmania infatum, as well as the QSAR model for toxicity activity. Most of the evaluated ligands presented high antiparasitic activity. According to the docking results, the family of triazole derivatives presented the best affinity with the different macromolecular targets. The ADME results showed that most of the evaluated compounds present adequate conditions to be administered orally. Naphthoquinone derivatives show good biological activity results, depending on the substituents attached to the quinone ring, and perhaps the potential to be converted into drugs or starting molecules.

Quinoa is an ancestral crop in the Andean region, characterized by its adaptability to different agroclimatic conditions, great nutritional value, and broad genetic variability. A preliminary approach for understanding the genetics of quinoa materials entails a morphologic characterization, which can provide the basis for the selection of materials that satisfy the needs of farmers and consumers. Therefore, this study aimed to evaluate the phenotypic characteristics of thirty genetic C. quinoa accessions for the selection of outstanding accessions in terms of yield and grain quality. A randomized complete block design was used, with nine replications for each accession under greenhouse conditions. Nine quantitative and twelve qualitative descriptors were evaluated with descriptive analysis, Spearman correlation variance, and multivariate and cluster analysis. The results showed that the accessions with heights greater than the average (>176.72 cm) and long panicles (>57.94 cm) presented lower yields and smaller seed sizes, thus decreasing the grain quality. The multivariate and cluster analyses established groups of accessions with good yields (>62.02 g of seeds per plant) and stable morphological characteristics. The proposed selection index, based on yield components and morphological descriptors, indicated four accessions as potential parents for quinoa breeding programs in Colombia.

Quinoa (Chenopodium quinoa Willd.) is an ancestral species from the Andean region, which is considered as a staple food for its populations. In Colombia, the crop has been gaining economic importance despite little information related to the varietal purity of cultivated materials. The department of Boyacá has a diversity of quinoas with potential for use, which can be an alternative for more productive crops. Thus, the objective of this research was to evaluate the yield and phenological aspects of 30 quinoa genetic materials in Boyacá and establish a selection index to differentiate them according to their yield. It was determined that the phenological cycle of the 30 genetic materials ranged between 144 and 189 days, the estimation of the yield components showed that the variables that contributed the most to the observed phenotypic variation were the panicle length, yield, seed diameter, and weight of 1000 seeds. Through the selection index, it was determined that the materials Quinua Primavera, Amarilla de Maranganí and Quinua Peruana, have the potential to increase productivity, since they present high yield, semi-late phenological cycle, large grain size and weight of 1000 seeds between 0.3 and 0.4 g. This research showed that phenotypic variables can be useful for the design of selection tools, oriented to the characteristics of agronomic importance and determined their usefulness to increase the efficiency of quinoa improvement programs.

Sacha inchi (Plukenetia volubilis L.) seed oil is a rich source of polyunsaturated fatty acids (PUFAs) that are beneficial for human health, whose nutritional efficacy is limited because of its low water solubility and labile bioaccessibility (compositional integrity). In this work, the encapsulation effect, using blended softgels of gelatin (G) and cactus mucilage (CM) biopolymers, on the PUFAs' bioaccessibility of P. volubilis seed oil was evaluated during in vitro simulated digestive processes (mouth, gastric, and intestinal). Gas chromatography-mass spectrometry (GC-MS) and gas chromatography with a flame ionization detector (GC-FID) were used for determining the chemical composition of P. volubilis seed oil both before and after in vitro digestion. The most abundant compounds in the undigested samples were α-linolenic, linoleic, and oleic acids with 59.23, 33.46, and 0.57 (g/100 g), respectively. The bioaccessibility of α-linolenic, linoleic, and oleic acid was found to be 1.70%, 1.46%, and 35.8%, respectively, along with the presence of some oxidation products. G/CM soft capsules are capable of limiting the in vitro bioaccessibility of PUFAs because of the low mucilage ratio in their matrix, which influences the enzymatic hydrolysis of gelatin, thus increasing the release of the polyunsaturated content during the simulated digestion.

2-chloro-3-(R-anilino)-1,4-naphthoquinones react with sodium azide upon refluxing in DMF. The thermochemistry of 2-azido-3-(R-anilino)-1,4-naphthoquinone is strongly modified by the substituent on aniline. Having an strong electron-donor like O-R results in the generation of a phenazine while having an electron-withdrawing substituent results in the formation of 2-amino-3-(R-anilino)-1,4-naphthoquinone. The products obtained are explained in terms of singlet and/or triplet nitrene chemistry.

A new crosslinking formulation using gelatin (G) and cactus mucilage (CM) biopolymers was developed, physicochemically characterized and proposed as an alternative wall material to traditional gelatin capsules (softgels). The effect of G concentration at different G/CM ratios (3:1, 1:1 and 1:3) was analyzed. Transparency, moisture content (MC), solubility in water (SW), morphology (scanning electron microscopy, SEM), vibrational characterization (Fourier transform infrared, FTIR), color parameters (CIELab) and thermal (differential scanning calorimetry/thermogravimetric analysis, DSC/TGA) properties of the prepared composite (CMC) capsules were estimated and compared with control (CC) capsules containing only G and glycerol. In addition, the dietary fiber (DF) content was also evaluated. Our results showed that the transparency of composite samples decreased gradually with the presence of CM, the G/CM ratio of 3:1 being suitable to form the softgels. The addition of CM decreased the MC, the SW and the lightness of the capsules. Furthermore, the presence of polysaccharide had significant effects on the morphology and thermal behavior of CMC in contrast to CC. FTIR spectra confirmed the CMC formation by crosslinking between CM and G biopolymers. The addition of CM to the softgels formulation influenced the DF content. Our findings support the feasibility of developing softgels using a formulation of CM and G as wall material with nutritional properties.

The host–guest inclusion complex structure and binding ability of two different quinolones with γ-cyclodextrin (γ-CD) were investigated in solution by means of UV–Vis and ¹H NMR spectroscopy. Competition of oxolinic and nalidixic acid molecules for the γ-CD cavity was evaluated by determination of association constants. Both quinolones form 1:1 inclusion complexes, their binding constants at room temperature (25 °C) under acidic and basic conditions were calculated using Benesi–Hildebrand equation. The stability of the complexes was dependent on the structure of the quinolone. In general, the weaker binding constants were observed for oxolinic acid-γ-CD complexes (1616 and 1765 M⁻¹) and the larger binding constants were obtained for nalidixic acid-γ-CD complexes (3760 and 3840 M⁻¹). ¹H NMR studies in D2O were performed to elucidate the structure of each inclusion complex, nalidixic acid molecule penetrates more deeply into the γ-CD cavity and an intermolecular hydrogen bond is formed. Knowledge about structure and relative stability of quinolone-γ-CD complexes will be useful for future applications of these antimicrobial agents in medicinal chemistry.

Naphthoquinone amino derivatives exhibit interesting physicochemical properties and a wide range of biological activities with potential medicinal applications. A clean, fast and simple method for the preparation of phenylamino-1,4-naphthoquinones is presented by the reaction of naphthoquinone (NQ) and anilines under ultrasound irradiation (US). Anilino derivatives were synthesized in good yields and shorter reaction times in comparison with the conventional method. This ultrasound procedure can be applied to the preparation of naphthoquinone derivatives with anilines containing electron-donor substituents (2-OMe, 4-OMe, 4-Me and 4-OEt) or halogen or electron-withdrawing substituents (4-F, 4-Cl, 4-Br, 3-F, 3-Cl, 3-Br, 4-Ac). This procedure was also applied to the reaction of anilines with 2,3-dichloro-1,4-naphthoquinone (DCNQ). A reaction mechanism involving an EDA complex is proposed based on NMR experiments and previous studies about solid/solid reactions. Graphical Abstract Open image in new window