Alfonso Alejo‐Armijo

Universidad de Jaén

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

Sofı́a Salido

Universidad de Jaén

A. Jorge Parola

Universidade Nova de Lisboa

Joaquı́n Altarejos

Universidad de Jaén

Fernando Piña

Universidade Nova de Lisboa

E. Ortega

Universidad de Jaén

Ambrósio Camuenho

Universidade Nova de Lisboa

Clara S. B. Gomes

Universidade Nova de Lisboa

César A. T. Laia

Universidade Nova de Lisboa

João Carlos Lima

Universidade Nova de Lisboa

Artur J. Moro

Universidade Nova de Lisboa

Cooperative Institutions

Universidade Nova de Lisboa

Rede de Química e Tecnologia

University of Lisbon

Universidad de Jaén

Universidad de Granada

Laboratório Associado para a Química Verde

Faculdade de Tecnologia e Ciências

University of Coimbra

Consejo Superior de Investigaciones Científicas

Romanian Academy

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Lactate dehydrogenase A inhibitors with a 2,8-dioxabicyclo[3.3.1]nonane scaffold: A contribution to molecular therapies for primary hyperoxalurias

Bioorganic Chemistry (2022)

Alfonso Alejo‐Armijo Cristina Cuadrado Joaquı́n Altarejos Miguel X. Fernandes Eduardo Salido

Primary hyperoxaluria

10.1016/j.bioorg.2022.106127

Cite

Citations (15)

Thermodynamic Stability of Flavylium Salts as a Valuable Tool To Design the Synthesis of A-Type Proanthocyanidin Analogues

The Journal of Organic Chemistry (2018)

Alfonso Alejo‐Armijo A. Jorge Parola Fernando Piña Joaquı́n Altarejos Sofı́a Salido

A convenient method to synthesize A-type proanthocyanidin analogues from flavylium salts and π-nucleophiles has been developed. It was found that the thermodynamic stability of the starting flavylium salt, assessed by the measurement of the apparent acidity constant (K′a), was the key parameter to design effective one-pot reactions between flavylium salts and nucleophiles such as phloroglucinol and (+)-catechin. When flavylium salts have a pK′a value of 1.7 or lower, the synthesis of the corresponding 2,8-dioxabyciclo[3.3.1]nonane derivative was properly achieved.

Chemical Stability

10.1021/acs.joc.8b01780

Cite

Citations (11)

CCDC 2207219: Experimental Crystal Structure Determination

The Cambridge Structural Database (2023)

Ambrósio Camuenho A. Jorge Parola Alfonso Alejo‐Armijo Clara S. B. Gomes César A. T. Laia

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

10.5517/ccdc.csd.cc2d2smx

Cite

Citations (0)

CCDC 1853345: Experimental Crystal Structure Determination

The Cambridge Structural Database (2019)

Alfonso Alejo‐Armijo Artur J. Moro A. Jorge Parola João Carlos Lima Fernando Piña

10.5517/ccdc.csd.cc206kb4

Cite

Citations (0)

Ground and excited state properties of furanoflavylium derivatives

Physical Chemistry Chemical Physics (2019)

Alfonso Alejo‐Armijo Nuno Basílio Adilson A. Freitas António L. Maçanita João Carlos Lima

The comparison of the ground-state reactivity of anthocyanins and aurone model compounds (i.e. with and without the furano bridge) has shown that the kinetic paradigm does not depend on the bridge but only on the hydroxyl substituent pattern, independently of the presence of the bridge: (i) bell shaped kinetics for those with two hydroxyl substituents in position 4' and 7, and (ii) four distinct kinetic steps for the mono substituted compounds with a hydroxyl in position 4'. The excited state proton transfer (ESPT) properties of these compounds were also investigated using steady-state and time-resolved spectroscopic techniques. It was found that the ESPT efficiency is significantly higher for the bridged compounds. Interestingly, pH-dependent steady-state fluorescence emission experiments show that in 4',7-dihydroxyfuranoflavylium the hydroxyl group in position 7 is the more acidic one in the excited state, while 1H NMR titration curves indicate a higher acidity constant in the ground state for the proton at the hydroxyl group in position 4'. Differently, the fluorescence emission spectrum of the quinoidal base deprotonated at position 7 is only observed upon excitation of the flavylium cation while the one from the base deprotonated at 4' is observed upon direct excitation.

10.1039/c9cp04917g

Cite

Citations (8)

Halogenated Analogs to Natural A-Type Proanthocyanidins: Evaluation of Their Antioxidant and Antimicrobial Properties and Possible Application in Food Industries

Molecules (2024)

Antonio Cobo Alfonso Alejo‐Armijo Daniel Cruz Joaquı́n Altarejos Sofı́a Salido

A description of new antimicrobial agents suitable for food industries has become necessary, and natural compounds are being considered as promising sources of new active derivatives to be used with the aim of improving food safety. We have previously described desirable antimicrobial and antibiofilm activities against foodborne bacteria by analogs to A-type proanthocyanidins (PACs) with a nitro (NO

Natural food

Food additive

10.3390/molecules29153622

Cite

Citations (1)

A diagnostic tool for assessing the conservation condition of cellulose nitrate and acetate in heritage collections: quantifying the degree of substitution by infrared spectroscopy

Heritage Science (2020)

Sofia Nunes Francesca Ramacciotti Artur Neves Eva Mariasole Angelin A.M. Ramos

Abstract Cellulose nitrate and acetate are materials at risk in heritage collections because it is not possible to predict the evolution of their conservation state over time. Knowing that the degree of substitution (DS) of these materials correlates with their state of conservation because the fundamental degradation mechanism is hydrolysis, in this work, DS was measured in historical objects and artworks. Infrared spectra were used to develop and optimize calibration curves for cellulose nitrate and acetate references that were next applied to calculate DS values of heritage objects. The extent of hydrolysis measured, with this tool, correlated well with the physical deterioration assessed through the sample hardness (Shore A) which was measured with a Durometer. Calibration curves were optimized in reference materials by Attenuated Total Reflectance (ATR-FTIR) and Micro Fourier Transform Infrared Spectroscopy (μFTIR). The DS values of the AC reference materials was previously calculated by nuclear magnetic resonance spectroscopy. The calibration curves were obtained plotting DS as a function of the ratio between a reference peak (which does not suffer relevant changes during degradation) and selected peaks that monitor the degradation for cellulose acetate and nitrate polymers (avoiding the interference of plasticizers). The reference peak for both was the COC stretching mode (νCOC). The probe peak was, for cellulose nitrate, the NO 2 asymmetric stretching (ν a NO 2 ) and, for cellulose acetate, the OH stretching mode (νOH). This ratio was then applied to calculate DS values of historical materials, in good and poor conservation condition; in situ by ATR, and in micro-samples collected from artworks by μFTIR. This selection comprises cinematographic and photographic films dated from the 1890s to the 1960s, and contemporary works of art made with cellulose acetate sheets by Portuguese artist José Escada dated from the 1960s. Finally, by comparison with the original estimated DS values, we show how this tool permits to define the state of degradation of these complex polymer matrixes. Thus, establishing the quantification of the DS as a novel tool to monitor the degradation of cellulose ester plastics, contributing in this way for a sustainable preservation of an irreplaceable heritage.

Cellulose acetate

Attenuated total reflection

10.1186/s40494-020-00373-4

Cite

Citations (58)

Phytochemicals and Biological Activities of Laurel Tree (Laurus nobilis)

Natural Product Communications (2017)

Alfonso Alejo‐Armijo Joaquı́n Altarejos Sofı́a Salido

This review summarizes the chemical composition reported up to date on Laurus nobilis L. (Lauraceae), an evergreen shrub or tree cultivated for its aromatic leaves and ornamental interest. It has been focused on non-volatile phytochemicals such as sesquiterpene lactones, flavonoids and proanthocyanidins, among others. Moreover, biological activities of laurel extracts and pure compounds have also been reviewed.

Laurus nobilis

Lauraceae

Ornamental plant

Osmanthus fragrans

Magnoliaceae

10.1177/1934578x1701200519

Cite

Citations (41)

CCDC 1585959: Experimental Crystal Structure Determination

The Cambridge Structural Database (2019)

Amparo Navarro Sonia B. Jiménez‐Pulido Andrés Garzón-Ruíz Nuria A. Illán‐Cabeza Francisco Hueso‐Ureña

10.5517/ccdc.csd.cc1q79z7

Cite

Citations (0)

Effect of Methyl, Hydroxyl, and Chloro Substituents in Position 3 of 3′,4′,7-Trihydroxyflavylium: Stability, Kinetics, and Thermodynamics

Chemistry - A European Journal (2016)

Alfonso Alejo‐Armijo Sofı́a Salido Joaquı́n Altarejos A. Jorge Parola Sandra Gago

The effect of methyl, hydroxyl, and chloride substituents in position 3 of the 3',4',7-trihydroxyflavylium core structure was studied. The stability, relative energy of each of chemical species (thermodynamics), and their rates of interconversion (kinetics) are very dependent on these substituents. By comparing the mole fraction distribution at equilibrium of the three multistate systems with the parent 3',4',7-trihydroxyflavylium, introduction of a methyl substituent in position 3 increases the mole fraction of hemiketal at the expense of the trans-chalcone and increases the hydration rate very significantly; a hydroxyl substituent in position 3 gives rise to a degradation process, as observed in anthocyanidins. In the case of 3-chloro-3',4',7-trihydroxyflavylium, a dramatic increase of the flavylium cation acidity was observed and a photochromic system can be operated upon irradiation of the respective trans-chalcone in 1 m HCl. According to the photochromic response of 3,3',4',7-tetrahydroxyflavylium and 3',4',7-trihydroxyflavylium, some requirements for a good photochromic performance are discussed.

Mole fraction

10.1002/chem.201601564

Cite

Citations (10)