A. Mainar - Academia.edu (original) (raw)

Papers by A. Mainar

Research paper thumbnail of β-Carotene, α-Tocoferol and Rosmarinic Acid encapsulated within PLA/PLGA microcarriers by Supercritical Emulsion Extraction: encapsulation efficiency, drugs shelf-life and antioxidant activity

The Journal of Supercritical Fluids

Research paper thumbnail of Acute toxicological effects on the earthworm Eisenia fetida of 18 common pharmaceuticals in artificial soil

The Science of the total environment, Jan 9, 2015

Following soil applications of recycled water and biosolids, pharmaceutical residues can eventual... more Following soil applications of recycled water and biosolids, pharmaceutical residues can eventually enter the terrestrial environment. In vitro and in vivo assays have largely focused on the acute ecotoxicity of these compounds in aquatic systems. However, studies on the ecotoxicological effects of pharmaceuticals in soil biota are especially scarce. The aim of this study was to investigate the acute toxicity of 18 pharmaceuticals (4 NSAIDs, 5 blood lipid-lowering agents, 6 β-blockers and 3 antibiotics) that are usually found in the environment by using an Eisenia fetida bioassay. In addition, the presence of these pharmaceuticals in artificial soil was verified at the end of the test. Our results indicate that seven of the studied drugs cause acute adverse effects in E. fetida, in particular, the NSAIDs and the blood lipid-lowering agents. Ibuprofen (LC50=64.80mg/kg) caused the highest acute toxicity for all tested compounds, followed by diclofenac (LC50=90.49mg/kg) and simvastatin...

Research paper thumbnail of Solvent effects on Diels-Alder reactions. The use of aqueous mixtures of fluorinated alcohols and the study of reactions of acrylonitrile

Journal of the Chemical Society, Perkin Transactions 2, 1997

Rate, endo/exo, regio-and diastereo-facial selectivities of several Diels–Alder reactions were me... more Rate, endo/exo, regio-and diastereo-facial selectivities of several Diels–Alder reactions were measured in a series of fluorinated alcohol–water mixtures, whose solvophobicity has been determined by means of the solvophobic power (Sp) parameter. Solvophobicity is the main factor ...

Research paper thumbnail of Viscometric and volumetric properties of benzene + methyl acetate, or + methyl propanoate, or + methyl butanoate binary systems at 283.15, 298.15 and 313.15 K

Physics and Chemistry of Liquids, 2011

Viscosities and densities of three binary liquid mixtures, benzene + methyl acetate, benzene + me... more Viscosities and densities of three binary liquid mixtures, benzene + methyl acetate, benzene + methyl propanoate and benzene + methyl butanoate, have been measured at 283.15, 298.15 and 313.15 K, and atmospheric pressure. From experimental data, viscosity deviation, excess energy of activation for viscous flow, and excess molar volume were calculated and satisfactorily correlated with Redlich and Kister equation. Empirical and semiempirical equations and the predicted group-contribution

Research paper thumbnail of Extraction of Volatile Oil from Aromatic Plants with Supercritical Carbon Dioxide: Experiments and Modeling

Molecules, 2012

An overview of the studies carried out in our laboratories on supercritical fluid extraction (SFE... more An overview of the studies carried out in our laboratories on supercritical fluid extraction (SFE) of volatile oils from seven aromatic plants: pennyroyal (Mentha pulegium L.), fennel seeds (Foeniculum vulgare Mill.), coriander (Coriandrum sativum L.), savory (Satureja fruticosa Béguinot), winter savory (Satureja montana L.), cotton lavender (Santolina chamaecyparisus) and thyme (Thymus vulgaris), is presented. A flow apparatus with a 1 L extractor and two 0.27 L separators was built to perform studies at temperatures ranging from 298 to 353 K and pressures up to 30.0 MPa. The best compromise between yield and composition compared with hydrodistillation (HD) was achieved selecting the optimum experimental conditions of extraction and fractionation. The major differences between HD and SFE oils is the presence of a small percentage of cuticular waxes and the relative amount of thymoquinone, an oxygenated monoterpene with important biological

Research paper thumbnail of Solubility of gases in butanols

Fluid Phase Equilibria, 1999

ABSTRACT Solubilities of 15 nonpolar gases (He, Ne, Ar, Kr, Xe, H2, D2, N2, O2, CH4, C2H4, C2H6, ... more ABSTRACT Solubilities of 15 nonpolar gases (He, Ne, Ar, Kr, Xe, H2, D2, N2, O2, CH4, C2H4, C2H6, CF4, SF6, and CO2) in 2-methyl-2-propanol (tert-butanol) have been measured at the temperature 303.15 K and 101.33 kPa partial pressure of gas. Standard changes of the Gibbs energy of solution have been also determined from experimental data. The Lennard–Jones 6,12 pair potential parameters have been estimated for that solvent using the Scaled Particle Theory (SPT) and these parameters have been compared with those corresponding to the other isomers of butanol. It can be concluded that the derived energy parameters provide a measurement of the association of the alkanol. A version of the UNIFAC model has been applied and the corresponding interaction parameters for alkanes and alkanols have been determined.

Research paper thumbnail of Densities and excess molar volumes of the ternary mixture (1-butanol+n-hexane+1-chlorobutane) at 298.15 and 313.15 K. Application of the ERAS model

Fluid Phase Equilibria, 1998

Ž. Ž. Densities of the liquid mixtures n-hexaneq 1-chlorobutane and 1-butanolq n-hexaneq 1-chloro... more Ž. Ž. Densities of the liquid mixtures n-hexaneq 1-chlorobutane and 1-butanolq n-hexaneq 1-chlorobutane have been measured by the vibrating tube technique at 298.15 K and 313.15 K. With these densities, excess molar volumes were calculated. An extended version of the so-called ERAS model has been used for describing V E of the complete ternary system at 298.15 K. Qualitatively the ERAS-model gives an adequate representation of this system, being similar the shapes of both the experimental and the predicted curves. q 1998 Elsevier Science B.V.

Research paper thumbnail of Supercritical fluid extraction of Spanish sage essential oil: Optimization of the process parameters and modelling

The Journal of Supercritical Fluids, 2009

ABSTRACT The objective of the work was to optimize the extraction of Spanish sage essential oil b... more ABSTRACT The objective of the work was to optimize the extraction of Spanish sage essential oil by supercritical fluid (SFE) and to obtain extract useful for medical applications, such as, the case of Alzheimer disease. Different extraction conditions were tested and the evolution of the extracted oil composition was monitored by GC-MS analysis for the different fractions recovered at fixed time intervals. A comparison with an extract obtained by conventional hydrodistillation (HD) was also proposed for comparison. Particularly, different pressure and temperature values (90bar–40°C, corresponding to a density of 0.48g/ml, and 100bar–50°C, corresponding to a density of 0.38g/ml), three flow rates (1.32kg/h, 1.02kg/h and 0.72kg/h) and three particle sizes of the vegetable material (0.8mm, 0.5mm and 0.3mm) were studied. The major compounds found in the extracts were camphor (45%), 1,8-cineole (15%), camphene (4%), borneol (4%), myrcene (3%) and α-pinene (2%). A mathematical model was successfully applied to correlate the experimental data.

Research paper thumbnail of Supercritical antisolvent fractionation of ryanodol from Persea indica

The Journal of Supercritical Fluids, 2011

The objective of this study is the extraction and concentration of ryanodol, an insecticidal comp... more The objective of this study is the extraction and concentration of ryanodol, an insecticidal compound contained in a Canarian endemic plant, Persea indica, using supercritical fluid antisolvent fractionation (SAF). The pesticide has been first extracted from P. indica using ethanol; then, the ethanolic solution has been concentrated using the SAF technique, in which supercritical CO 2 is used to precipitate selected, non soluble compounds. The quantification of ryanodol in the different extracts was accomplished using HPLC-MS. Operating at 15.0 MPa and 35 • C (flow rates of 2.38 kg/h for CO 2 and of 5.7 mL/min for the ethanol solution) a fraction with a ryanodol content of 37.7% w/w is obtained, starting from the liquid extract containing only 7.5% w/w of this compound.

Research paper thumbnail of Supercritical Extraction and Separation of Antioxidants from Residues of the Wine Industry

Procedia Engineering, 2012

ABSTRACT The main objective of this research is to evaluate the possibility to use residues of th... more ABSTRACT The main objective of this research is to evaluate the possibility to use residues of the wine industry to produce antioxidant concentrates, more specifically, concentrates of gallic acid, catechin, epicatechin and resveratrol. For this purpose, Supercritical Antisolvent Fractionation (SAF) has been used. This technology allows to concentrate ina dry form the biologically active principles of interest for their direct application, providing simultaneously a uniform and suitable size of the product. The most abundant compounds recovered are cathechin (48.5 mg/Kg, epicathechin (36.3 mg/kg), gallic acid (108 mg/Kg) and resveratrol (170 mg/Kg).

Research paper thumbnail of Rotenone coprecipitation with biodegradable polymers by supercritical assisted atomization

ABSTRACT The aim of this study was to coprecipitate rotenone, a biopesticide, with biodegradable ... more ABSTRACT The aim of this study was to coprecipitate rotenone, a biopesticide, with biodegradable polymers using supercritical assisted atomization (SAA) process. Rotenone encapsulation can protect the pesticide from degradation thus reducing the quantity to be used. Different water soluble polymers were tested, such as polyethylene glycol (PEG), polyvinylpyrrolidone (PVP) and sodium alginate. Solutions with one or two solvents and rotenone suspensions were tested to perform the experiments. Different biodegradable polymer/pesticide ratios were tested: 2 and 8 in the case of PEG-rotenone coprecipitates, 25, 50 and 100 in the cases of PVP-rotenone and alginate-rotenone coprecipitates. The particles obtained were spherical with the mean diameter ranging between 0.6 and 1.5 mu m. The effective loading of the particles was evaluated by HPLC and the best results were obtained in the case of alginate-rotenone coprecipitates that show a coprecipitation efficiency close to 100% and for PEG-rotenone particles the efficiency was about 98%. PVP-rotenone composite microparticles showed the lowest coprecipitation efficiency that ranged between 30% and 50%.

Research paper thumbnail of β-Carotene, α-Tocoferol and Rosmarinic Acid encapsulated within PLA/PLGA microcarriers by Supercritical Emulsion Extraction: encapsulation efficiency, drugs shelf-life and antioxidant activity

The Journal of Supercritical Fluids

Research paper thumbnail of Acute toxicological effects on the earthworm Eisenia fetida of 18 common pharmaceuticals in artificial soil

The Science of the total environment, Jan 9, 2015

Following soil applications of recycled water and biosolids, pharmaceutical residues can eventual... more Following soil applications of recycled water and biosolids, pharmaceutical residues can eventually enter the terrestrial environment. In vitro and in vivo assays have largely focused on the acute ecotoxicity of these compounds in aquatic systems. However, studies on the ecotoxicological effects of pharmaceuticals in soil biota are especially scarce. The aim of this study was to investigate the acute toxicity of 18 pharmaceuticals (4 NSAIDs, 5 blood lipid-lowering agents, 6 β-blockers and 3 antibiotics) that are usually found in the environment by using an Eisenia fetida bioassay. In addition, the presence of these pharmaceuticals in artificial soil was verified at the end of the test. Our results indicate that seven of the studied drugs cause acute adverse effects in E. fetida, in particular, the NSAIDs and the blood lipid-lowering agents. Ibuprofen (LC50=64.80mg/kg) caused the highest acute toxicity for all tested compounds, followed by diclofenac (LC50=90.49mg/kg) and simvastatin...

Research paper thumbnail of Solvent effects on Diels-Alder reactions. The use of aqueous mixtures of fluorinated alcohols and the study of reactions of acrylonitrile

Journal of the Chemical Society, Perkin Transactions 2, 1997

Rate, endo/exo, regio-and diastereo-facial selectivities of several Diels–Alder reactions were me... more Rate, endo/exo, regio-and diastereo-facial selectivities of several Diels–Alder reactions were measured in a series of fluorinated alcohol–water mixtures, whose solvophobicity has been determined by means of the solvophobic power (Sp) parameter. Solvophobicity is the main factor ...

Research paper thumbnail of Viscometric and volumetric properties of benzene + methyl acetate, or + methyl propanoate, or + methyl butanoate binary systems at 283.15, 298.15 and 313.15 K

Physics and Chemistry of Liquids, 2011

Viscosities and densities of three binary liquid mixtures, benzene + methyl acetate, benzene + me... more Viscosities and densities of three binary liquid mixtures, benzene + methyl acetate, benzene + methyl propanoate and benzene + methyl butanoate, have been measured at 283.15, 298.15 and 313.15 K, and atmospheric pressure. From experimental data, viscosity deviation, excess energy of activation for viscous flow, and excess molar volume were calculated and satisfactorily correlated with Redlich and Kister equation. Empirical and semiempirical equations and the predicted group-contribution

Research paper thumbnail of Extraction of Volatile Oil from Aromatic Plants with Supercritical Carbon Dioxide: Experiments and Modeling

Molecules, 2012

An overview of the studies carried out in our laboratories on supercritical fluid extraction (SFE... more An overview of the studies carried out in our laboratories on supercritical fluid extraction (SFE) of volatile oils from seven aromatic plants: pennyroyal (Mentha pulegium L.), fennel seeds (Foeniculum vulgare Mill.), coriander (Coriandrum sativum L.), savory (Satureja fruticosa Béguinot), winter savory (Satureja montana L.), cotton lavender (Santolina chamaecyparisus) and thyme (Thymus vulgaris), is presented. A flow apparatus with a 1 L extractor and two 0.27 L separators was built to perform studies at temperatures ranging from 298 to 353 K and pressures up to 30.0 MPa. The best compromise between yield and composition compared with hydrodistillation (HD) was achieved selecting the optimum experimental conditions of extraction and fractionation. The major differences between HD and SFE oils is the presence of a small percentage of cuticular waxes and the relative amount of thymoquinone, an oxygenated monoterpene with important biological

Research paper thumbnail of Solubility of gases in butanols

Fluid Phase Equilibria, 1999

ABSTRACT Solubilities of 15 nonpolar gases (He, Ne, Ar, Kr, Xe, H2, D2, N2, O2, CH4, C2H4, C2H6, ... more ABSTRACT Solubilities of 15 nonpolar gases (He, Ne, Ar, Kr, Xe, H2, D2, N2, O2, CH4, C2H4, C2H6, CF4, SF6, and CO2) in 2-methyl-2-propanol (tert-butanol) have been measured at the temperature 303.15 K and 101.33 kPa partial pressure of gas. Standard changes of the Gibbs energy of solution have been also determined from experimental data. The Lennard–Jones 6,12 pair potential parameters have been estimated for that solvent using the Scaled Particle Theory (SPT) and these parameters have been compared with those corresponding to the other isomers of butanol. It can be concluded that the derived energy parameters provide a measurement of the association of the alkanol. A version of the UNIFAC model has been applied and the corresponding interaction parameters for alkanes and alkanols have been determined.

Research paper thumbnail of Densities and excess molar volumes of the ternary mixture (1-butanol+n-hexane+1-chlorobutane) at 298.15 and 313.15 K. Application of the ERAS model

Fluid Phase Equilibria, 1998

Ž. Ž. Densities of the liquid mixtures n-hexaneq 1-chlorobutane and 1-butanolq n-hexaneq 1-chloro... more Ž. Ž. Densities of the liquid mixtures n-hexaneq 1-chlorobutane and 1-butanolq n-hexaneq 1-chlorobutane have been measured by the vibrating tube technique at 298.15 K and 313.15 K. With these densities, excess molar volumes were calculated. An extended version of the so-called ERAS model has been used for describing V E of the complete ternary system at 298.15 K. Qualitatively the ERAS-model gives an adequate representation of this system, being similar the shapes of both the experimental and the predicted curves. q 1998 Elsevier Science B.V.

Research paper thumbnail of Supercritical fluid extraction of Spanish sage essential oil: Optimization of the process parameters and modelling

The Journal of Supercritical Fluids, 2009

ABSTRACT The objective of the work was to optimize the extraction of Spanish sage essential oil b... more ABSTRACT The objective of the work was to optimize the extraction of Spanish sage essential oil by supercritical fluid (SFE) and to obtain extract useful for medical applications, such as, the case of Alzheimer disease. Different extraction conditions were tested and the evolution of the extracted oil composition was monitored by GC-MS analysis for the different fractions recovered at fixed time intervals. A comparison with an extract obtained by conventional hydrodistillation (HD) was also proposed for comparison. Particularly, different pressure and temperature values (90bar–40°C, corresponding to a density of 0.48g/ml, and 100bar–50°C, corresponding to a density of 0.38g/ml), three flow rates (1.32kg/h, 1.02kg/h and 0.72kg/h) and three particle sizes of the vegetable material (0.8mm, 0.5mm and 0.3mm) were studied. The major compounds found in the extracts were camphor (45%), 1,8-cineole (15%), camphene (4%), borneol (4%), myrcene (3%) and α-pinene (2%). A mathematical model was successfully applied to correlate the experimental data.

Research paper thumbnail of Supercritical antisolvent fractionation of ryanodol from Persea indica

The Journal of Supercritical Fluids, 2011

The objective of this study is the extraction and concentration of ryanodol, an insecticidal comp... more The objective of this study is the extraction and concentration of ryanodol, an insecticidal compound contained in a Canarian endemic plant, Persea indica, using supercritical fluid antisolvent fractionation (SAF). The pesticide has been first extracted from P. indica using ethanol; then, the ethanolic solution has been concentrated using the SAF technique, in which supercritical CO 2 is used to precipitate selected, non soluble compounds. The quantification of ryanodol in the different extracts was accomplished using HPLC-MS. Operating at 15.0 MPa and 35 • C (flow rates of 2.38 kg/h for CO 2 and of 5.7 mL/min for the ethanol solution) a fraction with a ryanodol content of 37.7% w/w is obtained, starting from the liquid extract containing only 7.5% w/w of this compound.

Research paper thumbnail of Supercritical Extraction and Separation of Antioxidants from Residues of the Wine Industry

Procedia Engineering, 2012

ABSTRACT The main objective of this research is to evaluate the possibility to use residues of th... more ABSTRACT The main objective of this research is to evaluate the possibility to use residues of the wine industry to produce antioxidant concentrates, more specifically, concentrates of gallic acid, catechin, epicatechin and resveratrol. For this purpose, Supercritical Antisolvent Fractionation (SAF) has been used. This technology allows to concentrate ina dry form the biologically active principles of interest for their direct application, providing simultaneously a uniform and suitable size of the product. The most abundant compounds recovered are cathechin (48.5 mg/Kg, epicathechin (36.3 mg/kg), gallic acid (108 mg/Kg) and resveratrol (170 mg/Kg).

Research paper thumbnail of Rotenone coprecipitation with biodegradable polymers by supercritical assisted atomization

ABSTRACT The aim of this study was to coprecipitate rotenone, a biopesticide, with biodegradable ... more ABSTRACT The aim of this study was to coprecipitate rotenone, a biopesticide, with biodegradable polymers using supercritical assisted atomization (SAA) process. Rotenone encapsulation can protect the pesticide from degradation thus reducing the quantity to be used. Different water soluble polymers were tested, such as polyethylene glycol (PEG), polyvinylpyrrolidone (PVP) and sodium alginate. Solutions with one or two solvents and rotenone suspensions were tested to perform the experiments. Different biodegradable polymer/pesticide ratios were tested: 2 and 8 in the case of PEG-rotenone coprecipitates, 25, 50 and 100 in the cases of PVP-rotenone and alginate-rotenone coprecipitates. The particles obtained were spherical with the mean diameter ranging between 0.6 and 1.5 mu m. The effective loading of the particles was evaluated by HPLC and the best results were obtained in the case of alginate-rotenone coprecipitates that show a coprecipitation efficiency close to 100% and for PEG-rotenone particles the efficiency was about 98%. PVP-rotenone composite microparticles showed the lowest coprecipitation efficiency that ranged between 30% and 50%.