Browsing by Subject "Cyclodextrin"

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    A physicochemical, thermodynamical, structural and computational evaluation of kynurenic acid/cyclodextrin complexes
    (Elsevier, 2021-03-23) Matencio Durán, Adrián; Caldera, Fabrizio; Rubin Pedrazzo, Alberto; Monfared, Yousef Khazaei; Dhakar, Nilesh K.; Trotta, Francesco; Bioquímica y Biología Molecular A; Facultad de Biología
    In this work, the interaction between Kynurenic acid (KYNA) and several natural and modified cyclodextrins (CDs) is carried out. Among all the CD tested, HPβ-CD showed the strongest complexation constant (KF), with a value of 270.94 ± 29.80 M−1. Between natural (α- and β-) CDs, the complex of KYNA with β-CD was the most efficient. The inclusion complex of KYNA with CDs showed a strong influence of pH and temperature. The KF value decreased at high pH values, when the pKa was passed. Moreover, an increase of the temperature caused a decrease in the KF values. The thermodynamic parameters of the complexation (ΔH°, ΔS° and ΔG°) were studied with negative entropy, enthalpy and spontaneity of the process at 25 °C. Moreover, the inclusion complex was also characterized using FTIR and TGA. Finally, molecular docking calculations provided different interactions and their influence in the complexation constant.
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    Cyclodextrins increase phytosterol and tocopherol levels in suspension cultured cells obtained from mung beans and safflower
    (Wiley, 2017-07-13) Tudela, Libertad Raquel; Almagro Romero, Lorena; Miras Moreno, Begoña; Pedreño García, María Ángeles; Sabater Jara, Ana Belén; Biología Vegetal
    In this work, suspension-cultured cells of mung beans and safflower were used in order to analyze the effect of methyl jasmonate and/or cyclodextrins, on bioactive compound production such as phytosterols and tocopherols. The results indicated that mung bean suspension-cultured cells produced higher amount of total phytosterols and tocopherols. In particular, mung bean suspension-cultured cells produced almost 220-fold higher levels of tocopherols than safflower suspension-cultured cells in the best conditions. However, while cyclodextrins were able to enhance extracellular production of phytosterols, in the case of tocopherols, they only increased their intracellular accumulation. Our results showed that mung bean cells could be used as a highly efficient system for the production of phytosterols and tocopherols which have a wide range of biological activities.
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    Induction of extracellular defense-related proteins in suspension cultured-cells of Daucus carota elicited with cyclodextrins and methyljasmonate
    (Elsevier, 2014-02-18) Almagro Romero, Lorena; Pedreño García, María Ángeles; Sabater Jara, Ana Belén; Biología Vegetal
    Suspension cultured-cells (SCC) of Daucus carota were used to evaluate the effect of methyl jasmonate and cyclodextrins, separately or in combination, on the induction of defense responses, particularly the accumulation of pathogenesis-related proteins. A comparative study of the extracellular proteome (secretome) between control and elicited carrot SCC pointed to the presence of amino acid sequences homologous to glycoproteins which have inhibitory activity against the cell-wall-degrading enzymes secreted by pathogens and/or are induced when carrot cells are exposed to a pathogen elicitor. Other amino acid sequences were homologous to Leucine-Rich Repeat domain-containing proteins, which play an essential role in defense against pathogens, as well as in the recognition of microorganisms, making them important players in the innate immunity of this plant. Also, some tryptic peptides were shown to be homologous to a thaumatin-like protein, showing high specificity to abiotic stress and to different reticuline oxidase-like proteins that displayed high levels of antifungal activity, suggesting that methyl jasmonate and cyclodextrins could play a role in mediating defense-related gene product expression in SCC of D. carota. Apart from these elicitor-inducible proteins, we observed the presence of PR-proteins in both control and elicited carrot SCC, suggesting that their expression is mainly constitutive. These PR-proteins are putative class IV chitinases, which also have inhibitory activity against pathogen growth and the class III peroxidases that participate in response to environmental stress (e.g. pathogen attack and oxidative), meaning that they are involved in defense responses triggered by both biotic and abiotic factors.
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    Nanoparticles of betalamic acid derivatives with cyclodextrins. Physicochemistry, production characterization and stability
    (Elsevier, 2020-07-14) Guerrero Rubio, Alejandra; Matencio Durán, Adrián; Gandía Herrero, Fernando; López Nicolás, José Manuel; García Carmona, Francisco; Bioquímica y Biología Molecular A
    The use of betalains as bioactive compounds has been widely investigated. However, their use as a functional food requires a more exhaustive study because of their photosensitivity and poor stability. For this reason, this works studies the stabilization of two highly bioactive betalain derivatives, phenylethylamine-betaxanthin (Ph- Bx) and indoline-betacyanin (In-Bc) by nanoencapsulation in natural a modified cyclodextrins (CDs). Methyl- β-CD (Mβ-CD) showed the best results for Ph-Bx while Hydroxypropyl-β-CD (HPβ-CD) was better in the case of In- Bc. In addition, the effect of pH and temperature on encapsulation was studied finding that the encapsulation constant (KF) value increased as the pH decreased in the case of Ph-Bx but not in the case of In-Bc. The KF decreased as the temperatures increased. The thermodynamic parameters, ΔH◦, ΔS◦ and ΔG◦, were also calculated. Molecular docking provided further insight into how the different interactions influenced the encapsulation constant. The results show that the presence of CDs during the biotechnological synthesis of Ph-Bx and In- Bc increased production by 51 and 26%, respectively, and also increased the stability of both derivatives. This study represents a first step towards increasing the production of this type of compound for introduction into functional foods.
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    The use of cyclodextrins as solubility enhancers in the ORAC method may cause interference in the measurement of antioxidant activity
    (Elsevier, 2022-02-26) Navarro Orcajada, Silvia; Rodríguez Bonilla, Pilar; Matencio Durán, Adrián; Conesa Valverde, Irene; López Nicolás, José Manuel; García Carmona, Francisco; Bioquímica y Biología Molecular A
    The ability of cyclodextrins to enhance the water solubility of lipophilic compounds is used to modify the waterbased Oxygen Radical Absorbance Capacity (ORAC) method to measure antioxidant activity in vitro. However, the use of these solubility enhancers may alter fluorescent readings, which has led to contradictory results being described in the literature. The low specificity of these oligosaccharides and their controlled release effect can result in cyclodextrins forming inclusion complexes with other reagents in the assay, changing the kinetics. In this study, the cause of cyclodextrins’ interference in the ORAC method is evaluated through a physicochemical and computational approach. Cyclodextrins showed a clear increase in the fluorescent signal both in the presence and absence of the antioxidant oxyresveratrol, the precise effect being dependent on the type and concentration of cyclodextrin. Although the glucidic nature of cyclodextrins could play a minimal role in this effect, it seems that the main cause was the encapsulation of other substrates in the reaction, fluorescein and AAPH.
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    Use of b-cyclodextrins to enhance phytosterol production in cell suspension cultures of carrot (Daucus carota L.)
    (Springer, 2013-04-14) Pedreño García, María Ángeles; Sabater Jara, Ana Belén; Biología Vegetal
    Phytosterols are isoprenoid-derived compounds that play essential roles in plant growth and development as they are integral components of the plant cell membranes, and responsible for their permeability and fluidity. In this study, the effect of different types of beta-cyclodextrins (β-CD) on phytosterol production was evaluated using Daucus carota cell suspension cultures. A detailed analysis provides the optimal type and concentration of β-CD, elicitation time, and the optimal cell age and density. The highest levels of phytosterols produced by cells and secreted to the culture medium were obtained when 10 day-old D. carota cell suspension cultures, with an initial cell density of 200 g of fresh weight (FW) l−1, were incubated in the presence of 50 mM of methylated-β-CD (M-β-CD) for 144 h. In addition, M-β-CD significantly promoted the accumulation of phytosterol in the extracellular medium of D. carota cell suspension cultures, which was not observed in control cell suspension cultures. Moreover, these high phytosterol levels did not improve when methyl jasmonate (MJ) was added to the cell suspension cultures alone or combined with 50 mM M-β-CD, although MJ stimulated the formation of defense-related compounds. Therefore, the use of carrot cell suspension cultures seems a promising biotechnological alternative since the addition of β-CD to the culture medium not only induced the biosynthesis of phytosterols but also promoted their secretion into the culture medium, where they were accumulated and could be isolated easily.