molecules-logo

Journal Browser

Journal Browser

Special Issue "Green and Sustainable Solvents II: A Themed Issue in Honor of Professor Giovanni Sindona on the Occasion of His 70th Birthday"

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Green Chemistry".

Deadline for manuscript submissions: closed (31 March 2020) | Viewed by 41139

Printed Edition Available!
A printed edition of this Special Issue is available here.

Special Issue Editors

Dipartimento di Scienze della Salute, Università Magna Græcia, Viale Europa, Germaneto, Catanzaro, Italy
Interests: catalysis; green chemistry; organic synthesis; natural compounds; sustainable chemical processes
Special Issues, Collections and Topics in MDPI journals
Department of Health Sciences, Magna Græcia University, Viale Europa, 88100 Germaneto, CZ, Italy
Interests: catalysis; green chemistry; organic synthesis; natural compounds; sustainable chemical processes
Special Issues, Collections and Topics in MDPI journals
Dipartimento di Farmacia e Scienze della Salute e della Nutrizione, Università della Calabria, Arcavacata di Rende, Italy
Interests: organic synthesis; peptide synthesis; green chemistry; natural compounds; sustainable chemical processes; green solvents; deep eutectic solvents
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Prof. Giovanni Sindona has been a full professor of Organic Chemistry at the University of Calabria (Unical) since 1990, and has made seminal contributions to the areas of food chemistry, mass spectrometry, and green chemistry. He graduated in chemistry in 1972 with the highest marks and price at the University of Messina, by discussing a thesis held at its Institute of Organic Chemistry on modern bioanalytical applications of mass spectrometry. He completed his training in 1977 at both the Universities of Messina and Calabria, followed by a stage at the Institut für Physikalische Chemie of the University of Bonn (Germany) as a fellow of the prestigious Alexander von Humboldt Foundation (of which he became a lifetime member), by perfecting the knowledge in mass spectrometry in the group of professor Hans D. Beckey. Here he developed knowledge in desorption methodologies which allowed for the first time the direct characterization of proteins and nucleic acids by mass spectrometry. His formation was completed as NATO fellow at the King’s College of London, where at the beginning of 1980, under the direction of Professor Colin B. Reese, he developed new synthetic organic methods for the obtainment of nucleic acids segments with a predetermined sequence. Professor Sindona also taught organic chemistry at the new Faculty of Pharmacy of the University Magna Graecia of Catanzaro, from 1990 to 1993.

From 1990 to 2019, Prof Sindona has organized and directed five NATO International Schools for young researchers on the application of mass spectrometry to biomolecular chemistry held in Italy and abroad. In 2009, as a member of the programme The Science for Peace and Security, he organized a NATO-ARW seminary in Calabria for experts coming from all over the world on the “Detection of Biological Agents and Toxins for the Prevention of Bioterrorism in Homeland Security by Advanced Mass Spectrometric Methods”. In April 2016, as local director he organized the NATO SPS ASI 984915 event in Calabria, titled “Molecular Technologies for Detection of Chemical and Biological Agents”, for young PhD students on environmental security problems.

Professor Sindona is a co-author of nearly four-hundred scientific publications on international papers in the English language (246) and ten book chapters edited by international societies on themes related to his scientific applications (10). He has been an invited speaker at many national and international meetings in the chemistry field, author of national and international conferences (149) and a teacher at doctorate schools at the American University of Vanderbilt (Nashville) and Purdue (West-Lafayette) and at the Memorial University of St. Johns in Canada. He is interested in the topics of food chemistry, mass spectrometry, and green synthesis and extraction methods.

In the green chemistry field, he has obtained interesting results in the efficient and stereoselective synthesis of trans-4,5-diaminocyclopent-2-enones from furfural using green solvents, published in 2013 in ACS Sustainable Chemistry and in 2017 in Green Chemistry

Notably, interest has been raised in the use of homogeneous and heterogeneous catalysis in eco-friendly synthesis, which led to the publication of numerous and interesting papers on the major international scientific journals in the field of green chemistry and the development of new sustainable extraction methods of nutraceutical compounds from biomass. 

This Special Issue, “Green and Sustainable Solvents II:  A Themed Issue in Honor of Professor Giovanni Sindona on the Occasion of His 70th Birthday", aims to collect and publish recent advances in this interdisciplinary area. Research articles as well as reviews dealing with innovative techniques, alternative solvents, by-product valorization, and new routes for green solvents toward industrial applications are of interest. Manuscripts on how green solvents contribute to the development of natural products research are welcome. Molecules is very pleased to host this Special Issue, and invites scientists to submit their original contributions.

Dr. Monica Nardi
Prof. Antonio Procopio
Dr. Maria Luisa Di Gioia
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Green Chemistry
  • Organic synthesis
  • Catalysis
  • Green solvents
  • Environmental impact
  • Natural compounds

Published Papers (10 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review

15 pages, 3069 KiB  
Article
Immobilization in Ionogel: A New Way to Improve the Activity and Stability of Candida antarctica Lipase B
Molecules 2020, 25(14), 3233; https://doi.org/10.3390/molecules25143233 - 15 Jul 2020
Cited by 5 | Viewed by 1956
Abstract
New Candida antarctica lipase B derivatives with higher activity than the free enzyme were obtained by occlusion in an organogel of an ionic liquid (ionogel) based on the ionic liquid [Omim][PF6] and polyvinyl chloride. The inclusion of glutaraldehyde as a crosslinker [...] Read more.
New Candida antarctica lipase B derivatives with higher activity than the free enzyme were obtained by occlusion in an organogel of an ionic liquid (ionogel) based on the ionic liquid [Omim][PF6] and polyvinyl chloride. The inclusion of glutaraldehyde as a crosslinker improved the properties of the ionogel, allowing the enzymatic derivative to reach 5-fold higher activity than the free enzyme and also allowing it to be reused at 70 °C. The new methodology allows enzymatic derivatives to be designed by changing the ionic liquid, thus providing a suitable microenvironment for the enzyme. The ionic liquid may act on substrates to increase their local concentration, while reducing water activity in the enzyme’s microenvironment. All this allows the activity and selectivity of the enzyme to be improved and greener processes to be developed. The chemical composition and morphology of the ionogel were also studied by scanning electron microscopy–energy dispersive X-ray spectroscopy, finding that porosity, which was related with the chemical composition, was a key factor for the enzyme activity. Full article
Show Figures

Figure 1

26 pages, 2497 KiB  
Article
Bio-Based Solvents and Gasoline Components from Renewable 2,3-Butanediol and 1,2-Propanediol: Synthesis and Characterization
Molecules 2020, 25(7), 1723; https://doi.org/10.3390/molecules25071723 - 09 Apr 2020
Cited by 11 | Viewed by 4247
Abstract
In this study approaches for chemical conversions of the renewable compounds 1,2-propanediol (1,2-PD) and 2,3-butanediol (2,3-BD) that yield the corresponding cyclic ketals and glycol ethers have been investigated experimentally. The characterization of the obtained products as potential green solvents and gasoline components is [...] Read more.
In this study approaches for chemical conversions of the renewable compounds 1,2-propanediol (1,2-PD) and 2,3-butanediol (2,3-BD) that yield the corresponding cyclic ketals and glycol ethers have been investigated experimentally. The characterization of the obtained products as potential green solvents and gasoline components is discussed. Cyclic ketals have been obtained by the direct reaction of the diols with lower aliphatic ketones (1,2-PD + acetone → 2,2,4-trimethyl-1,3-dioxolane (TMD) and 2,3-BD + butanone-2 → 2-ethyl-2,4,5-trimethyl-1,3-dioxolane (ETMD)), for which the ΔH0r, ΔS0r and ΔG0r values have been estimated experimentally. The monoethers of diols could be obtained through either hydrogenolysis of the pure ketals or from the ketone and the diol via reductive alkylation. In the both reactions, the cyclic ketals (TMD and ETMD) have been hydrogenated in nearly quantitative yields to the corresponding isopropoxypropanols (IPP) and 3-sec-butoxy-2-butanol (SBB) under mild conditions (T = 120–140 °C, p(H2) = 40 bar) with high selectivity (>93%). Four products (TMD, ETMD, IPP and SBB) have been characterized as far as their physical properties are concerned (density, melting/boiling points, viscosity, calorific value, evaporation rate, Antoine equation coefficients), as well as their solvent ones (Kamlet-Taft solvatochromic parameters, miscibility, and polymer solubilization). In the investigation of gasoline blending properties, TMD, ETMD, IPP and SBB have shown remarkable antiknock performance with blending antiknock indices of 95.2, 92.7, 99.2 and 99.7 points, respectively. Full article
Show Figures

Graphical abstract

13 pages, 3093 KiB  
Article
The CO2 Absorption in Flue Gas Using Mixed Ionic Liquids
Molecules 2020, 25(5), 1034; https://doi.org/10.3390/molecules25051034 - 25 Feb 2020
Cited by 11 | Viewed by 2752
Abstract
Because of the appealing properties, ionic liquids (ILs) are believed to be promising alternatives for the CO2 absorption in the flue gas. Several ILs, such as [NH2emim][BF4], [C4mim][OAc], and [NH2emim[OAc], have been used to [...] Read more.
Because of the appealing properties, ionic liquids (ILs) are believed to be promising alternatives for the CO2 absorption in the flue gas. Several ILs, such as [NH2emim][BF4], [C4mim][OAc], and [NH2emim[OAc], have been used to capture CO2 of the simulated flue gas in this work. The structural changes of the ILs before and after absorption were also investigated by quantum chemical methods, FTIR, and NMR technologies. However, the experimental results and theoretical calculation showed that the flue gas component SO2 would significantly weaken the CO2 absorption performance of the ILs. SO2 was more likely to react with the active sites of the ILs than CO2. To improve the absorption capacity, the ionic liquid (IL) mixture [C4mim][OAc]/ [NH2emim][BF4] were employed for the CO2 absorption of the flue gas. It is found that the CO2 absorption capacity would be increased by about 25%, even in the presence of SO2. The calculation results suggested that CO2 could not compete with SO2 for reacting with the IL during the absorption process. Nevertheless, SO2 might be first captured by the [NH2emim][BF4] of the IL mixture, and then the [C4mim][OAc] ionic liquid could absorb more CO2 without the interference of SO2. Full article
Show Figures

Figure 1

10 pages, 1900 KiB  
Article
Studies on the Solubility of Terephthalic Acid in Ionic Liquids
Molecules 2020, 25(1), 80; https://doi.org/10.3390/molecules25010080 - 24 Dec 2019
Cited by 9 | Viewed by 7693
Abstract
Low solubility of terephthalic acid in common solvents makes its industrial production very difficult and not environmentally benign. Ionic liquids are known for their extraordinary solvent properties, with capability to dissolve a wide variety of materials, from common solvents to cellulose, opening new [...] Read more.
Low solubility of terephthalic acid in common solvents makes its industrial production very difficult and not environmentally benign. Ionic liquids are known for their extraordinary solvent properties, with capability to dissolve a wide variety of materials, from common solvents to cellulose, opening new possibilities to find more suitable solvents for terephthalic acid. This work presents studies on the solubility of terephthalic acid in ionic liquids, and demonstrates that terephthalic acid is soluble in ionic liquids, such as 1-ethyl-3-methylimidazolium diethylphosphate, 1-butyl-3-methylimidazolium acetate, and dialkylimidazolium chlorides up to four times higher than in DMSO. Additionally, the temperature effect and correlation of ionic liquid structure with solubility efficiency are discussed. Full article
Show Figures

Figure 1

13 pages, 915 KiB  
Article
Sustainable and Selective Extraction of Lipids and Bioactive Compounds from Microalgae
Molecules 2019, 24(23), 4347; https://doi.org/10.3390/molecules24234347 - 28 Nov 2019
Cited by 20 | Viewed by 4197
Abstract
The procedures for the extraction and separation of lipids and nutraceutics from microalgae using classic solvents have been frequently used over the years. However, these production methods usually require expensive and toxic solvents. Based on our studies involving the use of eco-sustainable methodologies [...] Read more.
The procedures for the extraction and separation of lipids and nutraceutics from microalgae using classic solvents have been frequently used over the years. However, these production methods usually require expensive and toxic solvents. Based on our studies involving the use of eco-sustainable methodologies and alternative solvents, we selected ethanol (EtOH) and cyclopentyl methyl ether (CPME) for extracting bio-oil and lipids from algae. Different percentages of EtOH in CPME favor the production of an oil rich in saturated fatty acids (SFA), useful to biofuel production or rich in bioactive compounds. The proposed method for obtaining an extract rich in saturated or unsaturated fatty acids from dry algal biomass is disclosed as eco-friendly and allows a good extraction yield. The method is compared both in extracted oil percentage yield and in extracted fatty acids selectivity to extraction by supercritical carbon dioxide (SC-CO2). Full article
Show Figures

Graphical abstract

11 pages, 6898 KiB  
Article
Facile Preparation of CuS Nanoparticles from the Interfaces of Hydrophobic Ionic Liquids and Water
Molecules 2019, 24(20), 3776; https://doi.org/10.3390/molecules24203776 - 21 Oct 2019
Cited by 6 | Viewed by 4048
Abstract
In this work, a two-phase system composed of hydrophobic ionic liquid (IL) and water phases was introduced to prepare copper sulfide (CuS) nanoparticles. It was found that CuS particles generated from the interfaces of carboxyl-functionalized IL and sodium sulfide (Na2S) aqueous [...] Read more.
In this work, a two-phase system composed of hydrophobic ionic liquid (IL) and water phases was introduced to prepare copper sulfide (CuS) nanoparticles. It was found that CuS particles generated from the interfaces of carboxyl-functionalized IL and sodium sulfide (Na2S) aqueous solution were prone to aggregate into nanoplates and those produced from the interfaces of carboxyl-functionalized IL and thioacetamide (TAA) aqueous solution tended to aggregate into nanospheres. Both the CuS nanoplates and nanospheres exhibited a good absorption ability for ultraviolet and visible light. Furthermore, the CuS nanoplates and nanospheres showed highly efficient photocatalytic activity in degrading rhodamine B (RhB). Compared with the reported CuS nanostructures, the CuS nanoparticles prepared in this work could degrade RhB under natural sunlight irradiation. Finally, the production of CuS from the interfaces of hydrophobic IL and water phases had the advantages of mild reaction conditions and ease of operation. Full article
Show Figures

Figure 1

14 pages, 2554 KiB  
Article
Eco-Friendly Extraction and Characterisation of Nutraceuticals from Olive Leaves
Molecules 2019, 24(19), 3481; https://doi.org/10.3390/molecules24193481 - 25 Sep 2019
Cited by 33 | Viewed by 3737
Abstract
Olive tree (Olea europaea L.) leaf, a waste by-product of the olive oil industry, is an inexpensive and abundant source of biophenols of great interest for various industrial applications in the food supplement, cosmetic, and pharmaceutical industries. In this work, the aqueous [...] Read more.
Olive tree (Olea europaea L.) leaf, a waste by-product of the olive oil industry, is an inexpensive and abundant source of biophenols of great interest for various industrial applications in the food supplement, cosmetic, and pharmaceutical industries. In this work, the aqueous extraction of high-added value compounds from olive leaves by using microfiltered (MF), ultrapure (U), and osmosis-treated (O) water was investigated. The extraction of target compounds, including oleuropein (Olp), hydroxytyrosol (HyTyr), tyrosol (Tyr), verbascoside (Ver), lutein (Lut), and rutin (Rut), was significantly affected by the characteristics of the water used. Indeed, according to the results of liquid chromatography tandem mass spectrometry, the extracting power of microfiltered water towards rutin resulted very poor, while a moderate extraction was observed for oleuropein, verbascoside, and lutein. On the other hand, high concentrations of hydroxytyrosol were detected in the aqueous extracts produced with microfiltered water. The extraction power of ultrapure and osmosis-treated water proved to be very similar for the bio-active compounds oleuropein, verbascoside, lutein, and rutin. The results clearly provide evidence of the possibility of devising new eco-friendly strategies based on the use of green solvents which can be applied to recover bioactive compounds from olive leaves. Full article
Show Figures

Graphical abstract

9 pages, 3779 KiB  
Article
Protic Ionic Liquids as Efficient Solvents in Microwave-Assisted Extraction of Rhein and Emodin from Rheum palmatum L.
Molecules 2019, 24(15), 2770; https://doi.org/10.3390/molecules24152770 - 30 Jul 2019
Cited by 17 | Viewed by 2703
Abstract
Rheum palmatum L. (R. palmatum L.) is a traditional Chinese herb and food, in which rhein and emodin are the main bioactive components. The extraction of the two compounds from R. palmatum L. is, thus, of great importance. In this work, protic [...] Read more.
Rheum palmatum L. (R. palmatum L.) is a traditional Chinese herb and food, in which rhein and emodin are the main bioactive components. The extraction of the two compounds from R. palmatum L. is, thus, of great importance. In this work, protic ionic liquids (PILs) were applied in the microwave-assisted extraction (MAE) of rhein and emodin from R. palmatum L., which avoids the toxicity of organic solvents. The results of the present study indicate that PILs possessing higher polarity exhibit higher extraction ability due to their stronger absorption ability for microwave irradiation. Compared with conventional solvents, such as methanol, trichloromethane, and deep eutectic solvents (DESs), the PIL, 1-butyl-3-himidazolium methanesulfonate ([BHim]MeSO3) reported herein is more efficient. The selected extraction conditions of liquid–solid ratio, microwave irradiation time, microwave irradiation power, and PIL concentration were 40 g·g−1, 50 s, 280 W, and 80%, respectively. Under the selected conditions, the extraction yields of rhein and emodin were 7.8 and 4.0 mg·g−1, respectively. These results suggest that PILs are efficient extraction solvents for the separation of active components from natural products. Full article
Show Figures

Figure 1

11 pages, 2557 KiB  
Article
Direct Bioelectricity Generation from Sago Hampas by Clostridium beijerinckii SR1 Using Microbial Fuel Cell
Molecules 2019, 24(13), 2397; https://doi.org/10.3390/molecules24132397 - 28 Jun 2019
Cited by 18 | Viewed by 2835
Abstract
Microbial fuel cells offer a technology for simultaneous biomass degradation and biological electricity generation. Microbial fuel cells have the ability to utilize a wide range of biomass including carbohydrates, such as starch. Sago hampas is a starchy biomass that has 58% starch content. [...] Read more.
Microbial fuel cells offer a technology for simultaneous biomass degradation and biological electricity generation. Microbial fuel cells have the ability to utilize a wide range of biomass including carbohydrates, such as starch. Sago hampas is a starchy biomass that has 58% starch content. With this significant amount of starch content in the sago hampas, it has a high potential to be utilized as a carbon source for the bioelectricity generation using microbial fuel cells by Clostridium beijerinckii SR1. The maximum power density obtained from 20 g/L of sago hampas was 73.8 mW/cm2 with stable cell voltage output of 211.7 mV. The total substrate consumed was 95.1% with the respect of 10.7% coulombic efficiency. The results obtained were almost comparable to the sago hampas hydrolysate with the maximum power density 56.5 mW/cm2. These results demonstrate the feasibility of solid biomass to be utilized for the power generation in fuel cells as well as high substrate degradation efficiency. Thus, this approach provides a promising way to exploit sago hampas for bioenergy generation. Full article
Show Figures

Figure 1

Review

Jump to: Research

19 pages, 2028 KiB  
Review
Improved Carotenoid Processing with Sustainable Solvents Utilizing Z-Isomerization-Induced Alteration in Physicochemical Properties: A Review and Future Directions
Molecules 2019, 24(11), 2149; https://doi.org/10.3390/molecules24112149 - 07 Jun 2019
Cited by 59 | Viewed by 6237
Abstract
Carotenoids—natural fat-soluble pigments—have attracted considerable attention because of their potential to prevent of various diseases, such as cancer and arteriosclerosis, and their strong antioxidant capacity. They have many geometric isomers due to the presence of numerous conjugated double bonds in the molecule. However, [...] Read more.
Carotenoids—natural fat-soluble pigments—have attracted considerable attention because of their potential to prevent of various diseases, such as cancer and arteriosclerosis, and their strong antioxidant capacity. They have many geometric isomers due to the presence of numerous conjugated double bonds in the molecule. However, in plants, most carotenoids are present in the all-E-configuration. (all-E)-Carotenoids are characterized by high crystallinity as well as low solubility in safe and sustainable solvents, such as ethanol and supercritical CO2 (SC-CO2). Thus, these properties result in the decreased efficiency of carotenoid processing, such as extraction and emulsification, using such sustainable solvents. On the other hand, Z-isomerization of carotenoids induces alteration in physicochemical properties, i.e., the solubility of carotenoids dramatically improves and they change from a “crystalline state” to an “oily (amorphous) state”. For example, the solubility in ethanol of lycopene Z-isomers is more than 4000 times higher than the all-E-isomer. Recently, improvement of carotenoid processing efficiency utilizing these changes has attracted attention. Namely, it is possible to markedly improve carotenoid processing using safe and sustainable solvents, which had previously been difficult to put into practical use due to the low efficiency. The objective of this paper is to review the effect of Z-isomerization on the physicochemical properties of carotenoids and its application to carotenoid processing, such as extraction, micronization, and emulsification, using sustainable solvents. Moreover, aspects of Z-isomerization methods for carotenoids and functional difference, such as bioavailability and antioxidant capacity, between isomers are also included in this review. Full article
Show Figures

Graphical abstract

Back to TopTop