International Journal of Molecular Sciences

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161 KiB

Open AccessArticle

Acidic Pretreatment of Wheat Straw in Decanol for the Production of Surfactant, Lignin and Glucose

by Sinisa Marinkovic, Jean Le Bras, Véronique Nardello-Rataj, Mickaël Agach and Boris Estrine

Int. J. Mol. Sci. 2012, 13(1), 348-357; https://doi.org/10.3390/ijms13010348 - 28 Dec 2011

Cited by 19 | Viewed by 7972

Abstract

Wheat straw is an abundant residue of agriculture which is increasingly being considered as feedstock for the production of fuels, energy and chemicals. The acidic decanol-based pre-treatment of wheat straw has been investigated in this work. Wheat straw hemicellulose has been efficiently converted [...] Read more.

Wheat straw is an abundant residue of agriculture which is increasingly being considered as feedstock for the production of fuels, energy and chemicals. The acidic decanol-based pre-treatment of wheat straw has been investigated in this work. Wheat straw hemicellulose has been efficiently converted during a single step operation into decyl pentoside surfactants and the remaining material has been preserved keeping all its promises as potential feedstock for fuels or value added platform chemicals such as hydroxymethylfurfural (HMF). The enzymatic digestibility of the cellulose contained in the straw residue has been evaluated and the lignin prepared from the material characterized. Wheat-based surfactants thus obtained have exhibited superior surface properties compared to fossil-based polyethoxylates decyl alcohol or alkyl oligoglucosides, some of which are largely used surfactants. In view of the growing importance of renewable resource-based molecules in the chemical industry, this approach may open a new avenue for the conversion of wheat straw into various chemicals. Full article

(This article belongs to the Special Issue Advances in Green Chemistry and Sustainable Chemistry 2011)

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103 KiB

Open AccessArticle

Use of Peroxyacetic Acid as Green Chemical on Yield and Sensorial Quality in Watercress (Nasturtium officinale R. Br.) Under Soilless Culture

by Gilda Carrasco, Claudia Moggia, Ingrid Jennifer Osses, Juan Eugenio Álvaro and Miguel Urrestarazu

Int. J. Mol. Sci. 2011, 12(12), 9463-9470; https://doi.org/10.3390/ijms12129463 - 19 Dec 2011

Cited by 6 | Viewed by 7000

Abstract

The goal of this research was to evaluate the effect of different doses of peroxyacetic acid on the productivity of watercress (Nasturtium officinale R. Br.) cultivated hydroponically using a constant nutritive solution. Green chemistry in protected horticulture seeks compatibility with the environment [...] Read more.

The goal of this research was to evaluate the effect of different doses of peroxyacetic acid on the productivity of watercress (Nasturtium officinale R. Br.) cultivated hydroponically using a constant nutritive solution. Green chemistry in protected horticulture seeks compatibility with the environment through the creation of biodegradable byproducts. In hydroponics, appropriate doses of peroxyacetic mixtures deliver these byproducts while also oxygenating the roots. Watercress producers who recirculate the nutritive solution can use these mixtures in order to increase oxygenation in the hydroponic system. The experiment took place between August and December 2009, beginning with the planting of the watercress seeds and concluding with the completion of the sensory panels. A completely random design was used, including three treatments and four repetitions, with applications of 0, 20 and 40 mg L⁻¹ of the peroxyacetic mixture. Measured variables were growth (plant height, leaf length and stem diameter), yield (weight per plant and dry matter) and organoleptic quality (color and sensory panel). The application of 40 mg L⁻¹ of the peroxyacetic mixture had a greater effect on the growth and development of the plants, which reached an average height of 29.3 cm, stem diameter of 3.3 mm and leaf length of 7.6 cm, whereas the control group reached an average height of only 20.2 cm, stem diameter of 1.9 mm and leaf length of 5.7 cm. The application of the peroxyacetic mixtures resulted in an improvement in growth parameters as well as in yield. Individual weights achieved using the 40 mg L⁻¹ dose were 1.3 g plant⁻¹ in the control group and 3.4 g plant⁻¹ in the experimental group (62% yield increase). Sensory analysis revealed no differences in organoleptic quality. Full article

(This article belongs to the Special Issue Advances in Green Chemistry and Sustainable Chemistry 2011)

142 KiB

Open AccessCommunication

Investigating Ionic Effects Applied to Water Based Organocatalysed Aldol Reactions

by Joshua P. Delaney and Luke C. Henderson

Int. J. Mol. Sci. 2011, 12(12), 9083-9094; https://doi.org/10.3390/ijms12129083 - 7 Dec 2011

Cited by 12 | Viewed by 6576

Abstract

Saturated aqueous solutions of various common salts were examined for their effect on aqueous aldol reactions catalysted by a highly active C₂-symmetric diprolinamide organocatalyst developed in our laboratory. With respect to the aldol reaction between cyclohexanone and 4-nitrobenzaldehyde, deionised water was [...] Read more.

Saturated aqueous solutions of various common salts were examined for their effect on aqueous aldol reactions catalysted by a highly active C₂-symmetric diprolinamide organocatalyst developed in our laboratory. With respect to the aldol reaction between cyclohexanone and 4-nitrobenzaldehyde, deionised water was always a superior medium to salt solutions though some correlation to increasing anion size and depression in enantiomeric excess could be observed. Additionally, the complete inhibition of catalyst activity observed when employing tap water could be alleviated by the inclusion of ethylenediaminetetraacetate (EDTA) into the aqueous media prior to reaction initiation. Extension of these reaction conditions demonstrated that these ionic effects vary on a case-to-case basis depending on the ketone/aldehyde combination. Full article

(This article belongs to the Special Issue Advances in Green Chemistry and Sustainable Chemistry 2011)

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194 KiB

Open AccessArticle

Comparative Study Using Different Infrared Zones of the Solventless Activation of Organic Reactions

by María Olivia Noguez Córdova, Carlos I. Flores Ramírez, Benjamín Velasco Bejarano, Gabriel A. Arroyo Razo, Francisco J. Pérez Flores, Vladimir Carranza Tellez and René Miranda Ruvalcaba

Int. J. Mol. Sci. 2011, 12(12), 8575-8580; https://doi.org/10.3390/ijms12128575 - 29 Nov 2011

Cited by 6 | Viewed by 7416

Abstract

In this work, the results of a study comparing the use of irradiation from different regions of the infrared spectrum for the promotion of several organic reactions, are presented and discussed. This use of eco-conditions provides a green approach to chemical synthesis. A [...] Read more.

In this work, the results of a study comparing the use of irradiation from different regions of the infrared spectrum for the promotion of several organic reactions, are presented and discussed. This use of eco-conditions provides a green approach to chemical synthesis. A set of ten different organic reactions were evaluated, including the Knoevenagel, Hantzsch, Biginelli and Meldrum reactions. It is important to highlight the use of a commercial device that produces infrared irradiation in the near infrared region and its distribution by convection providing heating uniformity, significantly reducing reaction times, achieving good yields and proceeding in the absence of solvent. It is also worth noting that a variety of different reactions may be performed at the same time. Finally, the products obtained were identified using TLC, together with corresponding MS-data, complementarily in comparison of NMR ¹H and ¹³C data with literature information. Full article

(This article belongs to the Special Issue Advances in Green Chemistry and Sustainable Chemistry 2011)

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171 KiB

Open AccessArticle

Removal of Mercury by Foam Fractionation Using Surfactin, a Biosurfactant

by Hau-Ren Chen, Chien-Cheng Chen, A. Satyanarayana Reddy, Chien-Yen Chen, Wun Rong Li, Min-Jen Tseng, Hung-Tsan Liu, Wei Pan, Jyoti Prakash Maity and Shashi B. Atla

Int. J. Mol. Sci. 2011, 12(11), 8245-8258; https://doi.org/10.3390/ijms12118245 - 21 Nov 2011

Cited by 43 | Viewed by 9548

Abstract

The separation of mercury ions from artificially contaminated water by the foam fractionation process using a biosurfactant (surfactin) and chemical surfactants (SDS and Tween-80) was investigated in this study. Parameters such as surfactant and mercury concentration, pH, foam volume, and digestion time were [...] Read more.

The separation of mercury ions from artificially contaminated water by the foam fractionation process using a biosurfactant (surfactin) and chemical surfactants (SDS and Tween-80) was investigated in this study. Parameters such as surfactant and mercury concentration, pH, foam volume, and digestion time were varied and their effects on the efficiency of mercury removal were investigated. The recovery efficiency of mercury ions was highly sensitive to the concentration of the surfactant. The highest mercury ion recovery by surfactin was obtained using a surfactin concentration of 10 × CMC, while recovery using SDS required < 10 × CMC and Tween-80 >10 × CMC. However, the enrichment of mercury ions in the foam was superior with surfactin, the mercury enrichment value corresponding to the highest metal recovery (10.4%) by surfactin being 1.53. Dilute solutions (2-mg L⁻¹ Hg²⁺) resulted in better separation (36.4%), while concentrated solutions (100 mg L⁻¹) enabled only a 2.3% recovery using surfactin. An increase in the digestion time of the metal solution with surfactin yielded better separation as compared with a freshly-prepared solution, and an increase in the airflow rate increased bubble production, resulting in higher metal recovery but low enrichment. Basic solutions yielded higher mercury separation as compared with acidic solutions due to the precipitation of surfactin under acidic conditions. Full article

(This article belongs to the Special Issue Advances in Green Chemistry and Sustainable Chemistry 2011)

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562 KiB

Open AccessArticle

Rapid and Green Analytical Method for the Determination of Quinoline Alkaloids from Cinchona succirubra Based on Microwave-Integrated Extraction and Leaching (MIEL) Prior to High Performance Liquid Chromatography

by Anne-Sylvie Fabiano-Tixier, Abdelhakim Elomri, Axelle Blanckaert, Elisabeth Seguin, Emmanuel Petitcolas and Farid Chemat

Int. J. Mol. Sci. 2011, 12(11), 7846-7860; https://doi.org/10.3390/ijms12117846 - 14 Nov 2011

Cited by 14 | Viewed by 10787

Abstract

Quinas contains several compounds, such as quinoline alkaloids, principally quinine, quinidine, cinchonine and cichonidine. Identified from barks of Cinchona, quinine is still commonly used to treat human malaria. Microwave-Integrated Extraction and Leaching (MIEL) is proposed for the extraction of quinoline alkaloids from [...] Read more.

Quinas contains several compounds, such as quinoline alkaloids, principally quinine, quinidine, cinchonine and cichonidine. Identified from barks of Cinchona, quinine is still commonly used to treat human malaria. Microwave-Integrated Extraction and Leaching (MIEL) is proposed for the extraction of quinoline alkaloids from bark of Cinchona succirubra. The process is performed in four steps, which ensures complete, rapid and accurate extraction of the samples. Optimal conditions for extraction were obtained using a response surface methodology reached from a central composite design. The MIEL extraction has been compared with a conventional technique soxhlet extraction. The extracts of quinoline alkaloids from C. succirubra obtained by these two different methods were compared by HPLC. The extracts obtained by MIEL in 32 min were quantitatively (yield) and qualitatively (quinine, quinidine, cinchonine, cinchonidine) similar to those obtained by conventional Soxhlet extraction in 3 hours. MIEL is a green technology that serves as a good alternative for the extraction of Cinchona alkaloids. Full article

(This article belongs to the Special Issue Advances in Green Chemistry and Sustainable Chemistry 2011)

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Graphical abstract

481 KiB

Open AccessArticle

Use of Brassica Plants in the Phytoremediation and Biofumigation Processes

by Marzena Szczygłowska, Anna Piekarska, Piotr Konieczka and Jacek Namieśnik

Int. J. Mol. Sci. 2011, 12(11), 7760-7771; https://doi.org/10.3390/ijms12117760 - 9 Nov 2011

Cited by 115 | Viewed by 11607

Abstract

In recent decades, serious contamination of soils by heavy metals has been reported. It is therefore a matter of urgency to develop a new and efficient technology for removing contaminants from soil. Another aspect to this problem is that environmental pollution decreases the [...] Read more.

In recent decades, serious contamination of soils by heavy metals has been reported. It is therefore a matter of urgency to develop a new and efficient technology for removing contaminants from soil. Another aspect to this problem is that environmental pollution decreases the biological quality of soil, which is why pesticides and fertilizers are being used in ever-larger quantities. The environmentally friendly solutions to these problems are phytoremediation, which is a technology that cleanses the soil of heavy metals, and biofumigation, a process that helps to protect crops using natural plant compounds. So far, these methods have only been used separately; however, research on a technology that combines them both using white cabbage has been carried out. Full article

(This article belongs to the Special Issue Advances in Green Chemistry and Sustainable Chemistry 2011)

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759 KiB

Open AccessArticle

A Sweet Killer: Mesoporous Polysaccharide Confined Silver Nanoparticles for Antibacterial Applications

by Robin J. White, Vitaly L. Budarin, James W.B. Moir and James H. Clark

Int. J. Mol. Sci. 2011, 12(9), 5782-5796; https://doi.org/10.3390/ijms12095782 - 9 Sep 2011

Cited by 26 | Viewed by 10051

Abstract

Silver nanoparticles (AgNP) confined within porous starch have been prepared in a simple, green and efficient manner, utilising the nanoporous structure of predominantly mesoporous starch (MS) to act as nanoparticle stabiliser, support and reducing surface. MS/AgNP materials present high surface areas (S [...] Read more.

Silver nanoparticles (AgNP) confined within porous starch have been prepared in a simple, green and efficient manner, utilising the nanoporous structure of predominantly mesoporous starch (MS) to act as nanoparticle stabiliser, support and reducing surface. MS/AgNP materials present high surface areas (S_BET > 150 m²g⁻¹) and mesopore volumes (V_meso > 0.45 cm³g⁻¹). The interaction of the AgNP precursor and forming nanoparticle nuclei with the mesoporous domains of the porous polysaccharide, direct porosity to increasingly narrower and more defined pore size distributions, indicative of a degree of cooperative assembly. Transmission electron microscopy images indicated the presence of spherical AgNP of a size reflective of the porous polysaccharide mesopore diameter (e.g., 5–25 nm), whilst XPS analysis confirmed the metallic Ag⁰ state. Materials were prepared at relatively low Ag loadings (< 0.18 mmol g−1), demonstrating excellent antimicrobial activity in solid and liquid phase testing against Gram negative (E. coli) and positive (S. aureus) model bacteria. The resulting materials are biocompatible and present a useful solid porous carbohydrate-based polymer vehicle to control the AgNP size regime and facilitate transference to a biological environment. Full article

(This article belongs to the Special Issue Advances in Green Chemistry and Sustainable Chemistry 2011)

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621 KiB

Open AccessArticle

Chemoenzymatic Synthesis and Chemical Recycling of Poly(ester-urethane)s

by Hiroto Hayashi, Yoshio Yanagishita and Shuichi Matsumura

Int. J. Mol. Sci. 2011, 12(9), 5490-5507; https://doi.org/10.3390/ijms12095490 - 29 Aug 2011

Cited by 4 | Viewed by 8440

Abstract

Novel poly(ester-urethane)s were prepared by a synthetic route using a lipase that avoids the use of hazardous diisocyanate. The urethane linkage was formed by the reaction of phenyl carbonate with amino acids and amino alcohols that produced urethane-containing diacids and hydroxy acids, respectively. [...] Read more.

Novel poly(ester-urethane)s were prepared by a synthetic route using a lipase that avoids the use of hazardous diisocyanate. The urethane linkage was formed by the reaction of phenyl carbonate with amino acids and amino alcohols that produced urethane-containing diacids and hydroxy acids, respectively. The urethane diacid underwent polymerization with polyethylene glycol and a,w-alkanediols and also the urethane-containing hydroxy acid monomer was polymerized by the lipase to produce high-molecular-weight poly(ester-urethane)s. The periodic introduction of ester linkages into the polyurethane chain by the lipase-catalyzed polymerization afforded chemically recyclable points. They were readily depolymerized in the presence of lipase into cyclic oligomers, which were readily repolymerized in the presence of the same enzyme. Due to the symmetrical structure of the polymers, poly(ester-urethane)s synthesized in this study showed higher T_m, Young’s modulus and tensile strength values. Full article

(This article belongs to the Special Issue Advances in Green Chemistry and Sustainable Chemistry 2011)

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654 KiB

Open AccessArticle

The Hildebrand Solubility Parameters of Ionic Liquids—Part 2

by Andrzej Marciniak

Int. J. Mol. Sci. 2011, 12(6), 3553-3575; https://doi.org/10.3390/ijms12063553 - 3 Jun 2011

Cited by 60 | Viewed by 9300

Abstract

The Hildebrand solubility parameters have been calculated for eight ionic liquids. Retention data from the inverse gas chromatography measurements of the activity coefficients at infinite dilution were used for the calculation. From the solubility parameters, the enthalpies of vaporization of ionic liquids were [...] Read more.

The Hildebrand solubility parameters have been calculated for eight ionic liquids. Retention data from the inverse gas chromatography measurements of the activity coefficients at infinite dilution were used for the calculation. From the solubility parameters, the enthalpies of vaporization of ionic liquids were estimated. Results are compared with solubility parameters estimated by different methods. Full article

(This article belongs to the Special Issue Advances in Green Chemistry and Sustainable Chemistry 2011)

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447 KiB

Open AccessArticle

Overcoming the Recalcitrance for the Conversion of Kenaf Pulp to Glucose via Microwave-Assisted Pre-Treatment Processes

by Beng Guat Ooi, Ashley L. Rambo and Miguel A. Hurtado

Int. J. Mol. Sci. 2011, 12(3), 1451-1463; https://doi.org/10.3390/ijms12031451 - 24 Feb 2011

Cited by 15 | Viewed by 9693

Abstract

This study evaluates the pre-treatment of cellulose from kenaf plant to yield sugar precursors for the production of ethanol or butanol for use as biofuel additives. In order to convert the crystalline cellulosic form to the amorphous form that can undergo enzymatic hydrolysis [...] Read more.

This study evaluates the pre-treatment of cellulose from kenaf plant to yield sugar precursors for the production of ethanol or butanol for use as biofuel additives. In order to convert the crystalline cellulosic form to the amorphous form that can undergo enzymatic hydrolysis of the glycosidic bond to yield sugars, kenaf pulp samples were subjected to two different pre-treatment processes. In the acid pre-treatment, the pulp samples were treated with 37.5% hydrochloric acid in the presence of FeCl₃ at 50 °C or 90 °C whereas in the alkaline method, the pulp samples were treated with 25% sodium hydroxide at room temperature and with 2% or 5% sodium hydroxide at 50 °C. Microwave-assisted NaOH-treatment of the cellulose was also investigated and demonstrated to be capable of producing high glucose yield without adverse environmental impact by circumventing the use of large amounts of concentrated acids i.e., 83–85% phosphoric acid employed in most digestion processes. The treated samples were digested with the cellulase enzyme from Trichoderma reesei. The amount of glucose produced was quantified using the Quantichrom^TM glucose bioassay for assessing the efficiency of glucose production for each of the treatment processes. The microwave-assisted alkaline pre-treatment processes conducted at 50 °C were found to be the most effective in the conversion of the crystalline cellulose to the amorphous form based on the significantly higher yields of sugar produced by enzymatic hydrolysis compared to the untreated sample. Full article

(This article belongs to the Special Issue Advances in Green Chemistry and Sustainable Chemistry 2011)

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Review

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230 KiB

Open AccessReview

Green Aspects of Techniques for the Determination of Currently Used Pesticides in Environmental Samples

by Jolanta Stocka, Maciej Tankiewicz, Marek Biziuk and Jacek Namieśnik

Int. J. Mol. Sci. 2011, 12(11), 7785-7805; https://doi.org/10.3390/ijms12117785 - 10 Nov 2011

Cited by 40 | Viewed by 9585

Abstract

Pesticides are among the most dangerous environmental pollutants because of their stability, mobility and long-term effects on living organisms. Their presence in the environment is a particular danger. It is therefore crucial to monitor pesticide residues using all available analytical methods. The analysis [...] Read more.

Pesticides are among the most dangerous environmental pollutants because of their stability, mobility and long-term effects on living organisms. Their presence in the environment is a particular danger. It is therefore crucial to monitor pesticide residues using all available analytical methods. The analysis of environmental samples for the presence of pesticides is very difficult: the processes involved in sample preparation are labor-intensive and time-consuming. To date, it has been standard practice to use large quantities of organic solvents in the sample preparation process; but as these solvents are themselves hazardous, solvent-less and solvent-minimized techniques are becoming popular. The application of Green Chemistry principles to sample preparation is primarily leading to the miniaturization of procedures and the use of solvent-less techniques, and these are discussed in the paper. Full article

(This article belongs to the Special Issue Advances in Green Chemistry and Sustainable Chemistry 2011)

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