Glucosinolates, a natural chemical arsenal: More to tell than the myrosinase story

Glucosinolates are a group of thioglucosides that belong to the class of plant nitrogen-containing natural products. So far, very little biological activity has been associated with intact glucosinolates. The hydrolysis of glucosinolates has, for long, attracted attention because of the potent biological activity of the hydrolysis products. From allelopathic to antiparasitic, antimicrobial and antineoplastic effects, the activity spectrum of the degradation products of typical glucosinolates has been the subject of much research. The present review seeks to address the various means of glucosinolate degradation (thermal, enzymatic, or chemical degradation) and the ensuing products. It also aims to draw a comparative profile of the various antimicrobial effects of these degradation products to provide a further understanding of the biological function of these important compounds.Fil: Abdel Massih, Roula M.. Central Michigan University; Estados UnidosFil: Debs, Espérance. University of Balamand; LíbanoFil: Othman, Leen. University of Balamand; LíbanoFil: Attieh, Jihad. University of Balamand; LíbanoFil: Cabrerizo, Franco Martín. Universidad Nacional de San Martin. Instituto Tecnológico de Chascomús - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Tecnológico de Chascomús; Argentin

Propiedades fotofísicas citotoxicidad de complejos de coordinación de Re(I)

Los complejos de Re(I) con ligando polipiridínicos han sido extensamente estudiados gracias a sus potenciales aplicaciones en diferentes campos de aplicación, siendo un área de interés la utilización de los mismos en procesos de fotosensibilización. En este artículo se han estudiado las propiedades fotofísicas y la citotoxicidad (evaluada en células de adenocarcinoma alveolar humano) de nuevos complejos de coordinación de Re(I) con ligandos polipiridínicos y beta-carbolinas como ligandos. Se encontró que la emisión de los complejos depende fuertemente del solvente y que los mismos poseen un alto rendimiento cuántico de 1O2. La viabilidad celular disminuyó significativamente al comparar los resultados con el ligando libre, siendo además dependiente del compuesto que se encuentra ligado al metal de transición.Facultad de Ciencias Agrarias y Forestale

Propiedades fotofísicas citotoxicidad de complejos de coordinación de Re(I)

Los complejos de Re(I) con ligando polipiridínicos han sido extensamente estudiados gracias a sus potenciales aplicaciones en diferentes campos de aplicación, siendo un área de interés la utilización de los mismos en procesos de fotosensibilización. En este artículo se han estudiado las propiedades fotofísicas y la citotoxicidad (evaluada en células de adenocarcinoma alveolar humano) de nuevos complejos de coordinación de Re(I) con ligandos polipiridínicos y beta-carbolinas como ligandos. Se encontró que la emisión de los complejos depende fuertemente del solvente y que los mismos poseen un alto rendimiento cuántico de 1O2. La viabilidad celular disminuyó significativamente al comparar los resultados con el ligando libre, siendo además dependiente del compuesto que se encuentra ligado al metal de transición.Facultad de Ciencias Agrarias y Forestale

Propiedades fotofísicas citotoxicidad de complejos de coordinación de Re(I)

Los complejos de Re(I) con ligando polipiridínicos han sido extensamente estudiados gracias a sus potenciales aplicaciones en diferentes campos de aplicación, siendo un área de interés la utilización de los mismos en procesos de fotosensibilización. En este artículo se han estudiado las propiedades fotofísicas y la citotoxicidad (evaluada en células de adenocarcinoma alveolar humano) de nuevos complejos de coordinación de Re(I) con ligandos polipiridínicos y beta-carbolinas como ligandos. Se encontró que la emisión de los complejos depende fuertemente del solvente y que los mismos poseen un alto rendimiento cuántico de 1O2. La viabilidad celular disminuyó significativamente al comparar los resultados con el ligando libre, siendo además dependiente del compuesto que se encuentra ligado al metal de transición.Facultad de Ciencias Agrarias y Forestale

N-methyl-β-carboline alkaloids: structure-dependent photosensitizing properties and localization in subcellular domains

N-methyl-Beta-carboline (bC) alkaloids, including normelinonine F and melinonine F, have been found in a vast range of living species playing different biological, biomedical and/or pharmacological roles. Despite this, molecular bases of the mechanisms through which these alkaloids would exert their effect still remain unknown. Fundamental aspects including the photosensitizing properties and intracellular internalization of a selected group of N-methyl-bC alkaloids were investigated herein. Data reveal that methylation of the bC main ring enhances its photosensitizing properties either by increasing its binding affinity with DNA as biomolecular target and/or by increasing its oxidation potential, in a structure dependent manner. As a general rule, N(9)-substituted bCs showed the highest photosensitizing efficiency. With the exception of 2-methyl-harminium, all the N-methyl-bCs investigated herein induce a similar DNA photodamage profile, dominated largely by oxidized purines. This fact represents a distinctive behavior when comparing with N-unsubstituted-bCs. On the other hand, although all the investigated compounds might accumulate mainly into the mitochondria of HeLa cells, methylation provides a distinctive dynamic pattern for mitochondrial uptake. While rapid (passive) diffusion is most probably reponsible for the prompt uptake/release of neutral bCs, an active transport appears to mediate the (reatively slow) uptake of the quaternary cationic bCs. This might be a consequence of a distinctive subcellular localization (mitochondrial membrane and/or matrix) or interaction with intracellular components. Biomedical and biotechnological implications are also discussed herein.Fil: Denofrio, Maria Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Rasse Suriani, Federico Ariel Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Paredes, Jose M.. Universidad de Granada. Facultad de Farmacia. Departamento de Fisicoquimica.; EspañaFil: Fassetta, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Crovetto, Luis. Universidad de Granada. Facultad de Farmacia. Departamento de Fisicoquimica.; EspañaFil: Giron, Maria D.. Universidad de Granada. Facultad de Farmacia.; EspañaFil: Salto, Rafael. Universidad de Granada. Facultad de Farmacia.; EspañaFil: Epe, Bernd. Johannes Gutenberg Universitat Mainz; AlemaniaFil: Cabrerizo, Franco Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentin

Albumin–Folate Conjugates for Drug‐targeting in Photodynamic Therapy

Photodynamic therapy (PDT) is based on the cytotoxicity of photosensitizers in the presence of light. Increased selectivity and effectivity of the treatment is expected if a specific uptake of the photosensitizers into the target cells, often tumor cells, can be achieved. An attractive transporter for that purpose is the folic acid receptor α (FRα), which is overexpressed on the surface of many tumor cells and mediates an endocytotic uptake. Here, we describe the synthesis and photobiological characterization of polar β‐carboline derivatives as photosensitizers covalently linked to folate‐tagged albumin as the carrier system. The particles were taken up by KB (human carcinoma) cells within <90 min and then co‐localized with a lysosomal marker. FRα antibodies prevented the uptake and also the corresponding conjugate without folate was not taken up. Accordingly, a folate‐albumin‐β‐carbolinium conjugate proved to be phototoxic, while the corresponding albumin–β‐carbolinium conjugates without FA were nontoxic, both with and without irradiation. An excess of free folate as competitor for the FRα‐mediated uptake completely inhibited the photocytotoxicity. Interestingly, the albumin conjugates are devoid of photodynamic activity under cell‐free conditions, as shown for DNA as a target. Thus, phototoxicity requires cellular uptake and lysosomal degradation of the conjugates. In conclusion, albumin–folate conjugates appear to be promising vehicles for a tumor cell targeted PDT.Facultad de Ciencias Exacta

Determining the molecular basis for the pH-dependent interaction between 2′-deoxynucleotides and 9H-pyrido[3,4-b]indole in its ground and electronic excited states

Interaction between norharmane and three different 2′-deoxynucleotides (dNMP) (2′-deoxyguanosine 5′-monophosphate (dGMP), 2′-deoxyadenosine 5′-monophosphate (dAMP) and 2′-deoxycytidine 5′-monophosphate (dCMP)), in aqueous solution, was studied in the ground state by means of UV-vis and ¹H-NMR spectroscopy and in the first electronic excited state using steady-state and time-resolved fluorescence spectroscopy. In all cases, the norharmane–dNMP interaction dependence on the pH was examined. Possible mechanisms for the interaction of both ground and electronic excited states of norharmane with nucleotides are discussed. Spectroscopic, molecular modeling and chemometric analysis were performed to further characterize the chemical structure of the complexes formed and to get additional information concerning the interaction between dNMPs and norharmane.Centro de Química InorgánicaInstituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

N-Methyl-β-carboline alkaloids: structure-dependent photosensitizing properties and localization in subcellular domains

N-Methyl-β-carboline (βC) alkaloids, including normelinonine F (1b) and melinonine F (2b), have been found in a vast range of living species playing different biological, biomedical and/or pharmacological roles. Despite this, molecular bases of the mechanisms through which these alkaloids would exert their effect still remain unknown. Fundamental aspects including the photosensitizing properties and intracellular internalization of a selected group of N-methyl-βC alkaloids were investigated herein. Data reveal that methylation of the βC main ring enhances its photosensitizing properties either by increasing its binding affinity with DNA as a biomolecular target and/or by increasing its oxidation potential, in a structure-dependent manner. As a general rule, N(9)-substituted βCs showed the highest photosensitizing efficiency. With the exception of 2-methyl-harminium, all the N-methyl-βCs investigated herein induce a similar DNA photodamage profile, dominated largely by oxidized purines. This fact represents a distinctive behavior when comparing with N-unsubstituted-βCs. On the other hand, although all the investigated compounds might accumulate mainly into the mitochondria of HeLa cells, methylation provides a distinctive dynamic pattern for mitochondrial uptake. While rapid (passive) diffusion is most probably reponsible for the prompt uptake/release of neutral βCs, an active transport appears to mediate the (reatively slow) uptake of the quaternary cationic βCs. This might be a consequence of a distinctive subcellular localization (mitochondrial membrane and/or matrix) or interaction with intracellular components. Biomedical and biotechnological implications are also discussed herein.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Photosensitized electron transfer within a self-assembled norharmane–2′-deoxyadenosine 5′-monophosphate (dAMP) complex

Norharmane is a compound that belongs to a family of alkaloids called β-carbolines (βCs). These alkaloids are present in a wide range of biological systems, playing a variety of significant photo-dependent roles. Upon UV-A irradiation, βCs are able to act as efficient photosensitizers. In this work, we have investigated the photosensitized oxidation of 2′-deoxyadenosine 5′-monophosphate (dAMP) by norharmane in an aqueous phase, upon UV-A (350 nm) irradiation. The effect of the pH was evaluated on both the interactions between norharmane and dAMP in the ground and electronic excited states, and on the dAMP photosensitized oxidation. A quite strong static interaction between norharmane and dAMP was observed, especially under those pH conditions where the protonated form of the alkaloid is present (pH < 7). Theoretical studies were performed to further characterize the static complex structure. The participation of reactive oxygen species (ROS) in the photosensitized reaction was also investigated and the photoproducts were characterized by means of UV-LDI-MS and ESI-MS. All the data provided herein indicate that electron transfer (Type I) within a self-assembled norharmane–dAMP complex is the operative mechanism in the dAMP photosensitization.Centro de Química Inorgánic

Latin America: Reduced S&T Investment Puts Sustainable Development at Risk

Latin America is home to more than 600 million people and has considerable natural and human resources. However, investment in science and technology (S&T) lags far behind that in developed countries. This gap represents a barrier to the development of economies based on knowledge and hampers the region's ability to tackle environmental and social problems. This lack of investment is evident in the extreme case of Venezuela, where much of the science workforce has fled economic chaos, but also in every Latin American country, including science powers such as Brazil and Argentina, where federal budgets in science, technology and education have been drastically reduced in recent years. Investments in S&T foster cooperation, commerce and good will and enhance resilience in the face of environmental and social turmoil. Therefore, scientists must start to actively engage governments and encourage long-term spending in S&T to support the development of Latin American societies.Universidad de Costa Rica/[]/UCR/Costa RicaSistema Nacional de Investigación/[]/SNI/SENACYT/PanamáUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Estación Experimental Agrícola Fabio Baudrit Moreno (EEAFBM)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Jardín Botánico Lankester (JBL