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25th Anniversary of Molecules—Recent Advances in Applied Chemistry

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

Deadline for manuscript submissions: closed (31 December 2021) | Viewed by 77126

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Engineered Nanomaterials Laboratory, Department of Chemistry, William Paterson University, 300, Pompton Road, Wayne, NJ 07470, USA
Interests: nanocatalysis; novel metal nanoparticles; macromolecules; polysiloxane based materials; polysilanes; metallopolysilicones; siloxane dendrimers; polymers for drug delivery; nanochemistry; hybridpolymers; green catalysis
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Special Issue Information

Dear Colleagues,

In 2020, we are celebrating the 25th anniversary of our journal Molecules. To date, the journal has published more than 20,000 papers, and the journal website attracts 115,000 monthly visits and more than 395,000 monthly page-views. Molecules has carved out a notable space in chemical litrature with a Impact Factor of 3.267 (2019) with a 5-Year Impact Factor of 3.589 (2019). Our sincerest thanks go to our readers, innumerable authors, anonymous peer reviewers, editors, and all the people working in some way for the journal who have joined their efforts for years. Without your help, we would never have achieved this.

To mark this important milestone, a Special Issue entitled “Recent Advances in Applied Chemistry” is being launched. This Special Issue collects communications, full papers, and high-quality review papers in the applied chemistry fields. We kindly invite and encourage all research groups covering various applied chemistry areas to make contributions to this Special Issue.

Prof. Dr. Bhanu P. S. Chauhan
Guest Editor

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Published Papers (26 papers)

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14 pages, 1118 KiB  
Article
The Application of Ultrasound in Honey: Antioxidant Activity, Inhibitory Effect on α-amylase and α-glucosidase, and In Vitro Digestibility Assessment
by Armando Peláez-Acero, Diana Belem Garrido-Islas, Rafael Germán Campos-Montiel, Lucio González-Montiel, Gabriela Medina-Pérez, Lorena Luna-Rodríguez, Uriel González-Lemus and Antonio de Jesús Cenobio-Galindo
Molecules 2022, 27(18), 5825; https://doi.org/10.3390/molecules27185825 - 08 Sep 2022
Cited by 6 | Viewed by 1422
Abstract
In the present study, the effects of ultrasound (10, 20, and 30 min) on the bioactive compounds, antioxidant capacity, enzymatic inhibition, and in vitro digestion of six honey extracts from the Oaxaca state, Mexico, were analyzed. Significant differences were found in each honey [...] Read more.
In the present study, the effects of ultrasound (10, 20, and 30 min) on the bioactive compounds, antioxidant capacity, enzymatic inhibition, and in vitro digestion of six honey extracts from the Oaxaca state, Mexico, were analyzed. Significant differences were found in each honey extract with respect to the ultrasonic treatment applied (p < 0.05). In the honey extract P-A1 treated with 20 min of ultrasound, the phenols reached a maximum concentration of 29.91 ± 1.56 mg EQ/100 g, and the flavonoids of 1.92 ± 0.01 mg EQ/100 g; in addition, an inhibition of α-amylase of 37.14 ± 0.09% was noted. There were also differences in the phases of intestinal and gastric digestion, presenting a decrease in phenols (3.92 ± 0.042 mg EQ/100 g), flavonoids (0.61 ± 0.17 mg EAG/100 mg), antioxidant capacity (8.89 ± 0.56 mg EAG/100 mg), and amylase inhibition (9.59 ± 1.38%). The results obtained from this study indicate that, in some honeys, the processing method could increase the concentration of bioactive compounds, the antioxidant capacity, and the enzymatic inhibition; however, when subjected to in vitro digestion, the properties of honey are modified. The results obtained could aid in the development of these compounds for use in traditional medicine as a natural source of bioactive compounds. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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11 pages, 4032 KiB  
Article
Carbon Papers from Tall Goldenrod Cellulose Fibers and Carbon Nanotubes for Application as Electromagnetic Interference Shielding Materials
by Jihyun Park, Lee Ku Kwac, Hong Gun Kim and Hye Kyoung Shin
Molecules 2022, 27(6), 1842; https://doi.org/10.3390/molecules27061842 - 11 Mar 2022
Cited by 3 | Viewed by 2007
Abstract
To transform tall goldenrods, which are invasive alien plant that destroy the ecosystem of South Korea, into useful materials, cellulose fibers isolated from tall goldenrods are applied as EMI shielding materials in this study. The obtained cellulose fibers were blended with CNTs, which [...] Read more.
To transform tall goldenrods, which are invasive alien plant that destroy the ecosystem of South Korea, into useful materials, cellulose fibers isolated from tall goldenrods are applied as EMI shielding materials in this study. The obtained cellulose fibers were blended with CNTs, which were used as additives, to improve the electrical conductivity. TGCF/CNT papers prepared using a facile paper manufacturing process with various weight percent ratios and thickness were carbonized at high temperatures and investigated as EMI shielding materials. The increase in the carbonization temperature, thickness, and CNT content enhanced the electrical conductivity and EMI SE of TGCF/CNT carbon papers. TGCF/CNT-15 papers, with approximately 4.5 mm of thickness, carbonized at 1300 °C exhibited the highest electrical conductivity of 6.35 S cm−1, indicating an EMI SE of approximately 62 dB at 1.6 GHz of the low frequency band. Additionally, the obtained TGCF/CNT carbon papers were flexible and could be bent and wound without breaking. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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12 pages, 2411 KiB  
Article
Antibiotic Removal from the Aquatic Environment with Activated Carbon Produced from Pumpkin Seeds
by İhsan Alacabey
Molecules 2022, 27(4), 1380; https://doi.org/10.3390/molecules27041380 - 18 Feb 2022
Cited by 19 | Viewed by 2259
Abstract
Antibiotics are among the most critical environmental pollutant drug groups. Adsorption is one of the methods used to eliminate these pollutants. In this study, activated carbon was produced from pumpkin seed shells and subsequently modified with KOH. The adsorbent obtained through this procedure [...] Read more.
Antibiotics are among the most critical environmental pollutant drug groups. Adsorption is one of the methods used to eliminate these pollutants. In this study, activated carbon was produced from pumpkin seed shells and subsequently modified with KOH. The adsorbent obtained through this procedure was used to remove ciprofloxacin from aqueous systems. Fourier Transform-Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), elemental, X-ray Photoelectron Spectroscopy (XPS), Brunauer–Emmett–Teller (BET) and Zeta analyses were used to characterize the adsorbent. The surface area, in particular, was found to be a very remarkable value of 2730 m2/g. The conditions of the adsorption experiments were optimized based on interaction time, adsorbent amount, pH and temperature. Over 99% success was achieved in removal operations carried out under the most optimal conditions, with an absorption capacity of 884.9 mg·g−1. In addition, the Langmuir isotherm was determined to be the most suitable model for the adsorption interaction. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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11 pages, 3267 KiB  
Article
Photolysis of the Insensitive Explosive 1,3,5-Triamino-2,4,6-trinitrobenzene (TATB)
by Annamaria Halasz, Jalal Hawari and Nancy N. Perreault
Molecules 2022, 27(1), 214; https://doi.org/10.3390/molecules27010214 - 30 Dec 2021
Cited by 5 | Viewed by 1584
Abstract
The explosive 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) is of particular interest due to its extreme insensitivity to impact, shock and heat, while providing a good detonation velocity. To determine its fate under environmental conditions, TATB powder was irradiated with simulated sunlight and, in water, under UV [...] Read more.
The explosive 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) is of particular interest due to its extreme insensitivity to impact, shock and heat, while providing a good detonation velocity. To determine its fate under environmental conditions, TATB powder was irradiated with simulated sunlight and, in water, under UV light at 254 nm. The hydrolysis of particles submerged in neutral and alkaline solutions was also examined. We found that, by changing experimental conditions (e.g., light source, and mass and physical state of TATB), the intermediates and final products were slightly different. Mono-benzofurazan was the major transformation product in both irradiation systems. Two minor transformation products, the aci-nitro form of TATB and 3,5-diamino-2,4,6-trinitrophenol, were detected under solar light, while 1,3,5-triamino-2-nitroso-4,6-dinitrobenzene, 1,3,5-triamino-2,4-dinitrobenzene and mono-benzofuroxan were produced under UV light. The product identified as 3,5-diamino-2,4,6-trinitrophenol was identical to the one formed in the dark under alkaline conditions (pH 13) and in water incubated at either 50 °C or aged at ambient conditions. Interestingly, when only a few milligrams of TATB were irradiated with simulated sunlight, the aci-isomer and mono-benzofurazan derivative were detected; however, the hydrolysis product 3,5-diamino-2,4,6-trinitrophenol formed only much later in the absence of light. This suggests that the water released from TATB to form mono-benzofurazan was trapped in the interstitial space between the TATB layers and slowly hydrolyzed the relatively stable aci-nitro intermediate to 3,5-diamino-2,4,6-trinitrophenol. This environmentally relevant discovery provides data on the fate of TATB in surface environments exposed to sunlight, which can transform the insoluble substrate into more soluble and corrosive derivatives, such as 3,5-diamino-2,4,6-trinitrophenol, and that some hydrolytic transformation can continue even without light. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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18 pages, 11150 KiB  
Article
Chemosensory Profile of South Tyrolean Pinot Blanc Wines: A Multivariate Regression Approach
by Simone Poggesi, Amanda Dupas de Matos, Edoardo Longo, Danila Chiotti, Ulrich Pedri, Daniela Eisenstecken, Peter Robatscher and Emanuele Boselli
Molecules 2021, 26(20), 6245; https://doi.org/10.3390/molecules26206245 - 15 Oct 2021
Cited by 4 | Viewed by 1860
Abstract
A multivariate regression approach based on sensory data and chemical compositions has been applied to study the correlation between the sensory and chemical properties of Pinot Blanc wines from South Tyrol. The sensory properties were identified by descriptive analysis and the chemical profile [...] Read more.
A multivariate regression approach based on sensory data and chemical compositions has been applied to study the correlation between the sensory and chemical properties of Pinot Blanc wines from South Tyrol. The sensory properties were identified by descriptive analysis and the chemical profile was obtained by HS-SPME-GC/MS and HPLC. The profiles of the most influencing (positively or negatively) chemical components have been presented for each sensory descriptor. Partial Least Square Regression (PLS) and Principal Component Regression (PCR) models have been tested and applied. Visual (clarity, yellow colour), gustatory (sweetness, sourness, saltiness, bitterness, astringency, and warmness) and olfactory (overall intensity, floral, apple, pear, tropical fruit, dried fruit, fresh vegetative, spicy, cleanness, and off-odours) descriptors have been correlated with the volatile and phenolic profiles, respectively. Each olfactory descriptor was correlated via a PCR model to the volatile compounds, whereas a comprehensive PLS2 regression model was built for the correlation between visual/gustatory descriptors and the phenolic fingerprint. “Apple” was the olfactory descriptor best modelled by PCR, with an adjusted R2 of 0.72, with only 20% of the validation samples falling out of the confidence interval (α = 95%). A PLS2 with 6 factors was chosen as the best model for gustatory and visual descriptors related to the phenolic compounds. Finally, the overall quality judgment could be explained by a combination of the calibrated sensory descriptors through a PLS model. This allowed the identification of sensory descriptors such as “olfactory intensity”, “warmness”, “apple”, “saltiness”, “astringency”, “cleanness”, “clarity” and “pear”, which relevantly contributed to the overall quality of Pinot Blanc wines from South Tyrol, obtained with two different winemaking processes and aged in bottle for 18 months. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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19 pages, 5903 KiB  
Article
Development of Amino Acids Functionalized SBA-15 for the Improvement of Protein Adsorption
by Raquel Gutiérrez-Climente, Margaux Clavié, Jérémie Gouyon, Giang Ngo, Yoann Ladner, Pascal Etienne, Pascal Dumy, Pierre Martineau, Martine Pugnière, Catherine Perrin, Gilles Subra and Ahmad Mehdi
Molecules 2021, 26(19), 6085; https://doi.org/10.3390/molecules26196085 - 08 Oct 2021
Cited by 4 | Viewed by 2200
Abstract
Ordered mesoporous materials and their modification with multiple functional groups are of wide scientific interest for many applications involving interaction with biological systems and biomolecules (e.g., catalysis, separation, sensor design, nano-science or drug delivery). In particular, the immobilization of enzymes onto solid supports [...] Read more.
Ordered mesoporous materials and their modification with multiple functional groups are of wide scientific interest for many applications involving interaction with biological systems and biomolecules (e.g., catalysis, separation, sensor design, nano-science or drug delivery). In particular, the immobilization of enzymes onto solid supports is highly attractive for industry and synthetic chemistry, as it allows the development of stable and cheap biocatalysts. In this context, we developed novel silylated amino acid derivatives (Si-AA-NH2) that have been immobilized onto SBA-15 materials in biocompatible conditions avoiding the use of toxic catalyst, solvents or reagents. The resulting amino acid-functionalized materials (SBA-15@AA) were characterized by XRD, TGA, EA, Zeta potential, nitrogen sorption and FT-IR. Differences of the physical properties (e.g., charges) were observed while the structural ones remained unchanged. The adsorption of the enzyme lysozyme (Lyz) onto the resulting functionalized SBA-15@AA materials was evaluated at different pHs. The presence of different functional groups compared with bare SBA-15 showed better adsorption results, for example, 79.6 nmol of Lyz adsorbed per m2 of SBA-15@Tyr compared with the 44.9 nmol/m2 of the bare SBA-15. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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22 pages, 3181 KiB  
Article
P∩N Bridged Cu(I) Dimers Featuring Both TADF and Phosphorescence. From Overview towards Detailed Case Study of the Excited Singlet and Triplet States
by Thomas Hofbeck, Thomas A. Niehaus, Michel Fleck, Uwe Monkowius and Hartmut Yersin
Molecules 2021, 26(11), 3415; https://doi.org/10.3390/molecules26113415 - 04 Jun 2021
Cited by 10 | Viewed by 2944
Abstract
We present an overview over eight brightly luminescent Cu(I) dimers of the type Cu2X2(P∩N)3 with X = Cl, Br, I and P∩N = 2-diphenylphosphino-pyridine (Ph2Ppy), 2-diphenylphosphino-pyrimidine (Ph2Ppym), 1-diphenylphosphino-isoquinoline (Ph2Piqn) including three new [...] Read more.
We present an overview over eight brightly luminescent Cu(I) dimers of the type Cu2X2(P∩N)3 with X = Cl, Br, I and P∩N = 2-diphenylphosphino-pyridine (Ph2Ppy), 2-diphenylphosphino-pyrimidine (Ph2Ppym), 1-diphenylphosphino-isoquinoline (Ph2Piqn) including three new crystal structures (Cu2Br2(Ph2Ppy)3 1-Br, Cu2I2(Ph2Ppym)3 2-I and Cu2I2(Ph2Piqn)3 3-I). However, we mainly focus on their photo-luminescence properties. All compounds exhibit combined thermally activated delayed fluorescence (TADF) and phosphorescence at ambient temperature. Emission color, decay time and quantum yield vary over large ranges. For deeper characterization, we select Cu2I2(Ph2Ppy)3, 1-I, showing a quantum yield of 81%. DFT and SOC-TDDFT calculations provide insight into the electronic structures of the singlet S1 and triplet T1 states. Both stem from metal+iodide-to-ligand charge transfer transitions. Evaluation of the emission decay dynamics, measured from 1.2 ≤ T ≤ 300 K, gives ∆E(S1-T1) = 380 cm−1 (47 meV), a transition rate of k(S1→S0) = 2.25 × 106 s−1 (445 ns), T1 zero-field splittings, transition rates from the triplet substates and spin-lattice relaxation times. We also discuss the interplay of S1-TADF and T1-phosphorescence. The combined emission paths shorten the overall decay time. For OLED applications, utilization of both singlet and triplet harvesting can be highly favorable for improvement of the device performance. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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12 pages, 13813 KiB  
Article
Preparation and Characterization of Carbon Fibers from Lyocell Precursors Grafted with Polyacrylamide via Electron-Beam Irradiation
by Hong Gun Kim, Yong-Sun Kim, Yun-Su Kuk, Lee Ku Kwac, Sun-Ho Choi, Jihyun Park and Hye Kyoung Shin
Molecules 2021, 26(9), 2459; https://doi.org/10.3390/molecules26092459 - 23 Apr 2021
Cited by 4 | Viewed by 1997
Abstract
Carbon fibers, which act as reinforcements in many applications, are often obtained from polyacrylonitrile (PAN). However, their production is expensive and results in waste problems. Therefore, we focused on producing carbon fibers from lyocell, a cellulose-based material, and analyzed the effects of the [...] Read more.
Carbon fibers, which act as reinforcements in many applications, are often obtained from polyacrylonitrile (PAN). However, their production is expensive and results in waste problems. Therefore, we focused on producing carbon fibers from lyocell, a cellulose-based material, and analyzed the effects of the process parameters on their mechanical properties and carbon yields. Lyocell was initially grafted with polyacrylamide (PAM) via electron-beam irradiation (EBI) and was subsequently stabilized and carbonized. Thermal analysis showed that PAM grafting increased the carbon yields to 20% at 1000 °C when compared to that of raw lyocell, which degraded completely at about 600 °C. Stabilization further increased this yield to 55%. The morphology of the produced carbon fibers was highly dependent on PAM concentration, with fibers obtained at concentrations ≤0.5 wt.% exhibiting clear, rigid, and round cross-sections with smooth surfaces, whereas fibers obtained from 2 and 4 wt.% showed peeling surfaces and attachment between individual fibers due to high viscosity of PAM. These features affected the mechanical properties of the fibers. In this study, carbon fibers of the highest tensile strength (1.39 GPa) were produced with 0.5 wt.% PAM, thereby establishing the feasibility of using EBI-induced PAM grafting on lyocell fabrics to produce high-performance carbon fibers with good yields. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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26 pages, 33199 KiB  
Article
Physicochemical and Adsorption Characteristics of Divinylbenzene-co-Triethoxyvinylsilane Microspheres as Materials for the Removal of Organic Compounds
by Alicja Bosacka, Małgorzata Zienkiewicz-Strzalka, Małgorzata Wasilewska, Anna Derylo-Marczewska and Beata Podkościelna
Molecules 2021, 26(8), 2396; https://doi.org/10.3390/molecules26082396 - 20 Apr 2021
Cited by 7 | Viewed by 2288
Abstract
In this work, organic-inorganic materials with spherical shape consisting of divinylbenzene (DVB) and triethoxyvinylsilane (TEVS) were synthesized and investigated by different complementary techniques. The obtained microspheres may be applied as sorbent systems for the purification of organic compounds from water. The hybrid microspheres [...] Read more.
In this work, organic-inorganic materials with spherical shape consisting of divinylbenzene (DVB) and triethoxyvinylsilane (TEVS) were synthesized and investigated by different complementary techniques. The obtained microspheres may be applied as sorbent systems for the purification of organic compounds from water. The hybrid microspheres combine the properties of the constituents depending on the morphologies and interfacial bonding. In this work, the influence of the molar ratio composition of crosslinked monomer (DVB) and silane coupling agent (TEVS) (DVB:TEVS molar ratios: 1:2, 1:1 and 2:1) on the morphology and quality of organic-inorganic materials have been examined. The materials were analysed using small angle X-ray scattering (SAXS) analysis, low-temperature nitrogen sorption, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) to provide information on their structural and surface properties. Moreover, thermal analysis was performed to characterize the thermal stability of the studied materials and the adsorbent-adsorbate interactions, while adsorption kinetic studies proved the utility of the synthesized adsorbents for water and wastewater treatment. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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16 pages, 2818 KiB  
Article
Development of Chitosan Microspheres through a Green Dual Crosslinking Strategy Based on Tripolyphosphate and Vanillin
by Rodolpho Fagundes Correa, Giovana Colucci, Noureddine Halla, João Alves Pinto, Arantzazu Santamaria-Echart, Silvia Priscila Blanco, Isabel Patrícia Fernandes and Maria Filomena Barreiro
Molecules 2021, 26(8), 2325; https://doi.org/10.3390/molecules26082325 - 16 Apr 2021
Cited by 7 | Viewed by 2859
Abstract
Microencapsulation procedures have recently focused attention on designing novel microspheres via green synthesis strategies. The use of chitosan (CS) as an encapsulating material has increased interest due to its unique bioactive properties and the various crosslinking possibilities offered by their functional groups. The [...] Read more.
Microencapsulation procedures have recently focused attention on designing novel microspheres via green synthesis strategies. The use of chitosan (CS) as an encapsulating material has increased interest due to its unique bioactive properties and the various crosslinking possibilities offered by their functional groups. The consolidation of the microspheres by physical crosslinking using sodium tripolyphosphate (TPP) combined with chemical crosslinking using vanillin (VA) open new opportunities in the framework of green dual crosslinking strategies. The developed strategy, a straightforward technique based on an aqueous medium avoiding complex separation/washing steps, offers advantages over the processes based on VA, mostly using water-in-oil emulsion approaches. Thus, in this work, the combination of TPP crosslinking (3, 5, and 10 wt.%) via spray-coagulation technique with two VA crosslinking methods (in situ and post-treatment using 1 wt.% VA) were employed in the preparation of microspheres. The microspheres were characterized concerning morphology, particle size, physicochemical properties, thermal stability, and swelling behavior. Results revealed that the combination of 5 wt.% TPP with in situ VA crosslinking led to microspheres with promising properties, being an attractive alternative for natural bioactives encapsulation due to the green connotations associated with the process. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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16 pages, 3282 KiB  
Article
The Addition of Microencapsulated or Nanoemulsified Bioactive Compounds Influences the Antioxidant and Antimicrobial Activities of a Fresh Cheese
by Elizabeth Pérez-Soto, Antonio de Jesús Cenobio-Galindo, Salvador Omar Espino-Manzano, Melitón Jesús Franco-Fernández, Fanny Emma Ludeña-Urquizo, Rubén Jiménez-Alvarado, Andrea Paloma Zepeda-Velázquez and Rafael Germán Campos-Montiel
Molecules 2021, 26(8), 2170; https://doi.org/10.3390/molecules26082170 - 09 Apr 2021
Cited by 18 | Viewed by 2384
Abstract
The objective of this study was to compare the effects of the incorporation of microcapsules or nanoemulsions with Opuntiaoligacantha on the quality of fresh cheese. Three treatments were established: Control, cheese with microcapsules (Micro), and cheese with nanoemulsion (Nano). The parameters evaluated [...] Read more.
The objective of this study was to compare the effects of the incorporation of microcapsules or nanoemulsions with Opuntiaoligacantha on the quality of fresh cheese. Three treatments were established: Control, cheese with microcapsules (Micro), and cheese with nanoemulsion (Nano). The parameters evaluated were physicochemical (moisture, ash, fat, proteins, and pH), microbiological (mesophilic aerobic bacteria, mold–yeast, and total coliforms), functional (total phenols, flavonoids, and antioxidant capacity), and texture (hardness, elasticity, cohesion, and chewiness) during storage for 45 days at 4 °C. The results showed that adding microcapsules and nanoemulsion did not affect the physicochemical parameters of the cheese. Total coliforms decreased in all samples from the first days of storage (Control: 4.23 ± 0.12, Micro: 3.27 ± 0.02, and Nano: 2.68 ± 0.08 Log10 CFU), as well as aerobic mesophiles and mold–yeast counts. Regarding the functional properties, an increase in total phenols was observed in all treatments. The texture profile analysis showed that the addition of microcapsules and nanoemulsion influenced hardness (Control: 8.60 ± 1.12, Micro: 1.61 ± 0.31, and Nano: 3.27 ± 0.37 N). The antimicrobial effect was greater when nanoemulsions were added, while adding microcapsules influenced the antioxidant activity more positively. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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27 pages, 8858 KiB  
Article
Mesoporous Carbons of Well-Organized Structure in the Removal of Dyes from Aqueous Solutions
by Magdalena Blachnio, Anna Derylo-Marczewska, Szymon Winter and Malgorzata Zienkiewicz-Strzalka
Molecules 2021, 26(8), 2159; https://doi.org/10.3390/molecules26082159 - 09 Apr 2021
Cited by 7 | Viewed by 1938
Abstract
Mesoporous carbons with differentiated properties were synthesized by using the method of impregnation of mesoporous well-organized silicas. The obtained carbonaceous materials and microporous activated carbon were investigated by applying different methods in order to determine their structural, surface and adsorption properties towards selected [...] Read more.
Mesoporous carbons with differentiated properties were synthesized by using the method of impregnation of mesoporous well-organized silicas. The obtained carbonaceous materials and microporous activated carbon were investigated by applying different methods in order to determine their structural, surface and adsorption properties towards selected dyes from aqueous solutions. In order to verify applicability of adsorbents for removing dyes the equilibrium and kinetic experimental data were measured and analyzed by applying various equations and models. The structural and acid-base properties of the investigated carbons were evaluated by Small-Angle X-ray Scattering (SAXS) technique, adsorption/desorption of nitrogen, potentiometric titration, and Transmission Electron Microscopy (TEM). The results of these techniques are complementary, indicating the type of porosity and structural ordering, e.g., the pore sizes determined from the SAXS data are in good agreement with those obtained from nitrogen sorption data. The SAXS and TEM data confirm the regularity of mesoporous carbon structure. The adsorption experiment, especially kinetic measurements, reveals the utility of mesoporous carbons in dye removing, taking into account not only the adsorption uptake but also the adsorption rate. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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14 pages, 8496 KiB  
Article
From Colloidal Dispersions of Zeolite Monolayers to Effective Solid Catalysts in Transformations of Bulky Organic Molecules: Role of Freeze-Drying and Dialysis
by Katarzyna Kałahurska, Pawel P. Ziemiański, Wieslaw J. Roth and Barbara Gil
Molecules 2021, 26(7), 2076; https://doi.org/10.3390/molecules26072076 - 04 Apr 2021
Cited by 2 | Viewed by 2233
Abstract
We investigated the properties and catalytic activity of zeolites with MWW topology obtained by unprecedented liquid exfoliation of the MCM-56 zeolite into solutions of monolayers and isolation/reassembly of the dispersed layers by various methods, with optional purification by dialysis or ammonium exchange. The [...] Read more.
We investigated the properties and catalytic activity of zeolites with MWW topology obtained by unprecedented liquid exfoliation of the MCM-56 zeolite into solutions of monolayers and isolation/reassembly of the dispersed layers by various methods, with optional purification by dialysis or ammonium exchange. The layers were recovered by flocculation with alcohol or ammonium nitrate and freeze-drying. Flocculation alone, even with ammonium nitrate, did not ensure removal of residual sodium cations resulting in catalysts with low activity. Dialysis of the solutions with dispersed monolayers proved to be efficient in removing sodium cations and preserving microporosity. The monolayers were also isolated as solids by freeze-drying. The highest BET area and pore volume obtained with the freeze-dried sample confirmed lyophilization efficiency in preserving layer structure. The applied test reaction, Friedel–Crafts alkylation of mesitylene, showed high benzyl alcohol conversion due to increased concentration of accessible acid centers caused by the presence of secondary mesoporosity. The applied treatments did not change the acid strength of the external acid sites, which are the most important ones for converting bulky organic molecules. Zeolite acidity was not degraded in the course of exfoliation into monolayers, showing the potential of such colloid dispersions for the formation of active catalysts. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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11 pages, 4207 KiB  
Article
Poly(Methyl Methacrylate) Coatings Containing Flame Retardant Additives from Suspensions in Water-2-Propanol
by Xuelin Li, Zhengzheng Wang, Sadman Sakib, Ritch Mathews and Igor Zhitomirsky
Molecules 2021, 26(7), 1974; https://doi.org/10.3390/molecules26071974 - 31 Mar 2021
Cited by 6 | Viewed by 2284
Abstract
A dip-coating technique is designed for deposition of poly(methyl methacrylate) (PMMA) from water/2-propanol mixture, avoiding the use of traditional toxic solvents. Solutions of PMMA macromolecules with high molecular weight (MW) are obtained for a water/2-propanol ratio of 0.15–0.33 and the solubilization [...] Read more.
A dip-coating technique is designed for deposition of poly(methyl methacrylate) (PMMA) from water/2-propanol mixture, avoiding the use of traditional toxic solvents. Solutions of PMMA macromolecules with high molecular weight (MW) are obtained for a water/2-propanol ratio of 0.15–0.33 and the solubilization mechanism is discussed. The ability to use concentrated PMMA solutions and high MW of the polymer are the key factors for the successful dip coating deposition. The coating mass for 10 g L−1 polymer solutions shows a maximum at a water/2-propanol ratio of 0.25. The deposition yield increases with the polymer concentration increase and with an increasing number of the deposited layers. PMMA deposits protect stainless steel from aqueous corrosion. The coating technique allows for the fabrication of composite coatings, containing flame-retardant materials (FRMs), such as commercial halloysite, huntite, hydrotalcite, and synthesized Al(OH)3, in the PMMA matrix. The FRM content in the coatings is modified by variation of the FRM content in colloidal suspensions. A fundamentally new method is developed, which is based on the salting out aided dispersive extraction of Al(OH)3 from the aqueous synthesis medium to 2-propanol. It is based on the use of hexadecylphosphonic acid molecules as extractors. The method offers advantages of reduced agglomeration. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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21 pages, 6662 KiB  
Article
Comparative Toxicity of Fly Ash: An In Vitro Study
by Elvira Rozhina, Ilnur Ishmukhametov, Läysän Nigamatzyanova, Farida Akhatova, Svetlana Batasheva, Sergey Taskaev, Carlos Montes, Yuri Lvov and Rawil Fakhrullin
Molecules 2021, 26(7), 1926; https://doi.org/10.3390/molecules26071926 - 30 Mar 2021
Cited by 11 | Viewed by 2603
Abstract
Fly ash produced during coal combustion is one of the major sources of air and water pollution, but the data on the impact of micrometer-size fly ash particles on human cells is still incomplete. Fly ash samples were collected from several electric power [...] Read more.
Fly ash produced during coal combustion is one of the major sources of air and water pollution, but the data on the impact of micrometer-size fly ash particles on human cells is still incomplete. Fly ash samples were collected from several electric power stations in the United States (Rockdale, TX; Dolet Hill, Mansfield, LA; Rockport, IN; Muskogee, OK) and from a metallurgic plant located in the Russian Federation (Chelyabinsk Electro-Metallurgical Works OJSC). The particles were characterized using dynamic light scattering, atomic force, and hyperspectral microscopy. According to chemical composition, the fly ash studied was ferro-alumino-silicate mineral containing substantial quantities of Ca, Mg, and a negligible concentration of K, Na, Mn, and Sr. The toxicity of the fly ash microparticles was assessed in vitro using HeLa cells (human cervical cancer cells) and Jurkat cells (immortalized human T lymphocytes). Incubation of cells with different concentrations of fly ash resulted in a dose-dependent decrease in cell viability for all fly ash variants. The most prominent cytotoxic effect in HeLa cells was produced by the ash particles from Rockdale, while the least was produced by the fly ash from Chelyabinsk. In Jurkat cells, the lowest toxicity was observed for fly ash collected from Rockport, Dolet Hill and Muscogee plants. The fly ash from Rockdale and Chelyabinsk induced DNA damage in HeLa cells, as revealed by the single cell electrophoresis, and disrupted the normal nuclear morphology. The interaction of fly ash microparticles of different origins with cells was visualized using dark-field microscopy and hyperspectral imaging. The size of ash particles appeared to be an important determinant of their toxicity, and the smallest fly ash particles from Chelyabinsk turned out to be the most cytotoxic to Jukart cells and the most genotoxic to HeLa cells. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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16 pages, 8810 KiB  
Article
Smart, Naturally-Derived Macromolecules for Controlled Drug Release
by Izabela Zaborniak, Angelika Macior and Paweł Chmielarz
Molecules 2021, 26(7), 1918; https://doi.org/10.3390/molecules26071918 - 29 Mar 2021
Cited by 7 | Viewed by 2592
Abstract
A series of troxerutin-based macromolecules with ten poly(acrylic acid) (PAA) or poly(2-dimethylaminoethyl methacrylate) (PDMAEMA) homopolymer side chains were synthesized by a supplemental activator and reducing agent atom transfer radical polymerization (SARA ATRP) approach. The prepared precisely-defined structures with low dispersity (Mw [...] Read more.
A series of troxerutin-based macromolecules with ten poly(acrylic acid) (PAA) or poly(2-dimethylaminoethyl methacrylate) (PDMAEMA) homopolymer side chains were synthesized by a supplemental activator and reducing agent atom transfer radical polymerization (SARA ATRP) approach. The prepared precisely-defined structures with low dispersity (Mw/Mn < 1.09 for PAA-based, and Mw/Mn < 1.71 for PDMAEMA-based macromolecules) exhibited pH-responsive behavior depending on the length of the polymer grafts. The properties of the received polyelectrolytes were investigated by dynamic light scattering (DLS) measurement to determine the hydrodynamic diameter and zeta potential upon pH changes. Additionally, PDMAEMA-based polymers showed thermoresponsive properties and exhibited phase transfer at a lower critical solution temperature (LCST). Thanks to polyelectrolyte characteristics, the prepared polymers were investigated as smart materials for controlled release of quercetin. The influence of the length of the polymer grafts for the quercetin release profile was examined by UV–VIS spectroscopy. The results suggest the strong correlation between the length of the polymer chains and the efficiency of active substance release, thus, the adjustment of the composition of the macromolecules characterized by branched architecture can precisely control the properties of smart delivery systems. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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17 pages, 5767 KiB  
Article
Spherical Al-MCM-41 Doped with Copper by Modified TIE Method as Effective Catalyst for Low-Temperature NH3-SCR
by Aleksandra Jankowska, Andrzej Kowalczyk, Małgorzata Rutkowska, Marek Michalik and Lucjan Chmielarz
Molecules 2021, 26(6), 1807; https://doi.org/10.3390/molecules26061807 - 23 Mar 2021
Cited by 3 | Viewed by 2194
Abstract
Aluminum containing silica spherical MCM-41 was synthesized and modified with copper by the template ion-exchange method (TIE) and its modified version, including treatment of the samples with ammonia solution directly after template ion-exchange (TIE-NH3). The obtained samples were characterized with respect [...] Read more.
Aluminum containing silica spherical MCM-41 was synthesized and modified with copper by the template ion-exchange method (TIE) and its modified version, including treatment of the samples with ammonia solution directly after template ion-exchange (TIE-NH3). The obtained samples were characterized with respect to their chemical composition (ICP-OES), structure (XRD), texture (low temperature N2 sorption), morphology (SEM-EDS), form and aggregation of deposited copper species (UV-vis DRS), reducibility of copper species (H2-TPR), and surface acidity (NH3-TPD). The deposition of copper by the TIE-NH3 method resulted in much better dispersion of this metal on the MCM-41 surface comparing to copper introduced by TIE method. It was shown that such highly dispersed copper species, mainly monomeric Cu2+ cations, deposited on aluminum containing silica spheres of MCM-41, are significantly more catalytically effective in the NH3-SCR process than analogous catalysts containing aggregated copper oxide species. The catalysts obtained by the TIE-NH3 method effectively operated in much broader temperature and were less active in the side process of direct ammonia oxidation by oxygen. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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7 pages, 857 KiB  
Communication
Chemical Adsorption Strategy for DMC-MeOH Mixture Separation
by Fucan Zhang, Ping Liu, Kan Zhang and Qing-Wen Song
Molecules 2021, 26(6), 1735; https://doi.org/10.3390/molecules26061735 - 19 Mar 2021
Cited by 3 | Viewed by 2027
Abstract
The effective separation of dimethyl carbonate (DMC) from its methanol mixture through simple, inexpensive and low energy-input method is a promising and challenging field in the process of organic synthesis. Herein, a reversible adsorption strategy through the assistance of superbase and CO2 [...] Read more.
The effective separation of dimethyl carbonate (DMC) from its methanol mixture through simple, inexpensive and low energy-input method is a promising and challenging field in the process of organic synthesis. Herein, a reversible adsorption strategy through the assistance of superbase and CO2 for DMC/methanol separation at ambient condition was described. The process was demonstrated effectively via the excellent CO2 adsorption efficiency. Notably, the protocol was also suitable to other alcohol (i.e., monohydric alcohol, dihydric alcohol, trihydric alcohol) mixtures. The study provided guidance for potential separation of DMC/alcohol mixture in the scale-up production. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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12 pages, 3972 KiB  
Article
Dispersant Molecules with Functional Catechol Groups for Supercapacitor Fabrication
by Kaelan Rorabeck and Igor Zhitomirsky
Molecules 2021, 26(6), 1709; https://doi.org/10.3390/molecules26061709 - 19 Mar 2021
Cited by 6 | Viewed by 1865
Abstract
Cathodes for supercapacitors with enhanced capacitive performance are prepared using MnO2 as a charge storage material and carbon nanotubes (CNT) as conductive additives. The enhanced capacitive properties are linked to the beneficial effects of catecholate molecules, such as chlorogenic acid and 3,4,5-trihydroxybenzamide, [...] Read more.
Cathodes for supercapacitors with enhanced capacitive performance are prepared using MnO2 as a charge storage material and carbon nanotubes (CNT) as conductive additives. The enhanced capacitive properties are linked to the beneficial effects of catecholate molecules, such as chlorogenic acid and 3,4,5-trihydroxybenzamide, which are used as co-dispersants for MnO2 and CNT. The dispersant interactions with MnO2 and CNT are discussed in relation to the chemical structures of the dispersant molecules and their biomimetic adsorption mechanisms. The dispersant adsorption is a key factor for efficient co-dispersion in ethanol, which facilitated enhanced mixing of the nanostructured components and allowed for improved utilization of charge storage properties of the electrode materials with high active mass of 40 mg cm−2. Structural peculiarities of the dispersant molecules are discussed, which facilitate dispersion and charging. Capacitive properties are analyzed using cyclic voltammetry, chronopotentiometry and impedance spectroscopy. A capacitance of 6.5 F cm−2 is achieved at a low electrical resistance. The advanced capacitive properties of the electrodes are linked to the microstructures of the electrodes prepared in the presence of the dispersants. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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Review

Jump to: Research

9 pages, 247 KiB  
Review
1946 and the Early History of Hydrosilylation
by Kenrick M. Lewis and Sabine Couderc
Molecules 2022, 27(14), 4341; https://doi.org/10.3390/molecules27144341 - 06 Jul 2022
Cited by 3 | Viewed by 1250
Abstract
Three events occurred in the second half of 1946 in three adjoining US States (NJ, NY, and PA) which marked the birth of Hydrosilylation Technology. They occurred before the landmark 1957 JACS paper and the 1958 issued US patent by Speier et al. [...] Read more.
Three events occurred in the second half of 1946 in three adjoining US States (NJ, NY, and PA) which marked the birth of Hydrosilylation Technology. They occurred before the landmark 1957 JACS paper and the 1958 issued US patent by Speier et al. and before Chalk and Harrod named the reaction. First, on 27 June 1946, Mackenzie et al., of Montclair Research Corp., applied for a patent to prepare addition compounds of hydridosilanes and unsaturated organic compounds. Then, on 9 October 1946, Wagner and Strother of Union Carbide Corp. applied for a patent on a process to produce organic compounds of silicon with Si–C bonds by reacting a hydridosilane and an alkene or alkyne in the presence of a catalyst metal of the platinum group. Finally, Sommer et al., submitted a paper on peroxide-catalyzed hydrosilylation to JACS on 17 December 1946. It was published in January 1947. The landmark patent interference § and priority § case law associated with the Mackenzie et al. and Wagner et al., applications is well known to patent attorneys. This presentation will retrace the origins of hydrosilylation and report events (1946–1960) in the history of the reaction that are most probably unknown to most authors and presenters of hydrosilylation investigations. George Wagner’s contribution to the birth of this technology is also highlighted. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
10 pages, 2834 KiB  
Review
Strategies Using Gelatin Microparticles for Regenerative Therapy and Drug Screening Applications
by Teruki Nii
Molecules 2021, 26(22), 6795; https://doi.org/10.3390/molecules26226795 - 10 Nov 2021
Cited by 25 | Viewed by 2900
Abstract
Gelatin, a denatured form of collagen, is an attractive biomaterial for biotechnology. In particular, gelatin particles have been noted due to their attractive properties as drug carriers. The drug release from gelatin particles can be easily controlled by the crosslinking degree of gelatin [...] Read more.
Gelatin, a denatured form of collagen, is an attractive biomaterial for biotechnology. In particular, gelatin particles have been noted due to their attractive properties as drug carriers. The drug release from gelatin particles can be easily controlled by the crosslinking degree of gelatin molecule, responding to the purpose of the research. The gelatin particles capable of drug release are effective in wound healing, drug screening models. For example, a sustained release of growth factors for tissue regeneration at the injured sites can heal a wound. In the case of the drug screening model, a tissue-like model composed of cells with high activity by the sustained release of drug or growth factor provides reliable results of drug effects. Gelatin particles are effective in drug delivery and the culture of spheroids or cell sheets because the particles prevent hypoxia-derived cell death. This review introduces recent research on gelatin microparticles-based strategies for regenerative therapy and drug screening models. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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21 pages, 30581 KiB  
Review
Fundamental Methods for the Phase Transfer of Nanoparticles
by Elijah Cook, Gianna Labiento and Bhanu P. S. Chauhan
Molecules 2021, 26(20), 6170; https://doi.org/10.3390/molecules26206170 - 13 Oct 2021
Cited by 8 | Viewed by 3499
Abstract
The utilization of nanoparticles for a variety of applications has raised much interest in recent years as new knowledge has emerged in nanochemistry. New and diverse methods for synthesis, characterization, and application of these particles have been discovered with differing degrees of ease [...] Read more.
The utilization of nanoparticles for a variety of applications has raised much interest in recent years as new knowledge has emerged in nanochemistry. New and diverse methods for synthesis, characterization, and application of these particles have been discovered with differing degrees of ease and reproducibility. Post-synthetic modification of nanoparticles is often a required step to facilitate their use in applications. The reaction conditions and chemical environment for the nanoparticle synthesis may not support or may conflict with further reactions. For this reason, it is beneficial to have phase transfer methods for nanoparticles to allow for their dispersion in a variety of solvents. Phase transfer methods are often limited in the types and sizes of particles that can be effectively dispersed in an immiscible solvent. Currently, general transfer methods for a wide variety of nanoparticles have not been identified. New routes for phase transfer allow for utilization of a larger range of particles in applications which were previously limited by solubility and reactivity issues. In this work, we will describe the fundamental methods for the phase transfer of metallic nanoparticles. We will look at the major problems and pitfalls of these methods. The applications of phase transfer will also be reviewed, mainly focusing on catalysis and drug delivery. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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44 pages, 14235 KiB  
Review
Recent Advances in the Synthesis of Polymer-Grafted Low-K and High-K Nanoparticles for Dielectric and Electronic Applications
by Bhausaheb V. Tawade, Ikeoluwa E. Apata, Nihar Pradhan, Alamgir Karim and Dharmaraj Raghavan
Molecules 2021, 26(10), 2942; https://doi.org/10.3390/molecules26102942 - 15 May 2021
Cited by 13 | Viewed by 4447
Abstract
The synthesis of polymer-grafted nanoparticles (PGNPs) or hairy nanoparticles (HNPs) by tethering of polymer chains to the surface of nanoparticles is an important technique to obtain nanostructured hybrid materials that have been widely used in the formulation of advanced polymer nanocomposites. Ceramic-based polymer [...] Read more.
The synthesis of polymer-grafted nanoparticles (PGNPs) or hairy nanoparticles (HNPs) by tethering of polymer chains to the surface of nanoparticles is an important technique to obtain nanostructured hybrid materials that have been widely used in the formulation of advanced polymer nanocomposites. Ceramic-based polymer nanocomposites integrate key attributes of polymer and ceramic nanomaterial to improve the dielectric properties such as breakdown strength, energy density and dielectric loss. This review describes the “grafting from” and “grafting to” approaches commonly adopted to graft polymer chains on NPs pertaining to nano-dielectrics. The article also covers various surface initiated controlled radical polymerization techniques, along with templated approaches for grafting of polymer chains onto SiO2, TiO2, BaTiO3, and Al2O3 nanomaterials. As a look towards applications, an outlook on high-performance polymer nanocomposite capacitors for the design of high energy density pulsed power thin-film capacitors is also presented. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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16 pages, 9337 KiB  
Review
Amygdalin: Toxicity, Anticancer Activity and Analytical Procedures for Its Determination in Plant Seeds
by Ewa Jaszczak-Wilke, Żaneta Polkowska, Marek Koprowski, Krzysztof Owsianik, Alyson E. Mitchell and Piotr Bałczewski
Molecules 2021, 26(8), 2253; https://doi.org/10.3390/molecules26082253 - 13 Apr 2021
Cited by 46 | Viewed by 12188
Abstract
Amygdalin (d-Mandelonitrile 6-O-β-d-glucosido-β-d-glucoside) is a natural cyanogenic glycoside occurring in the seeds of some edible plants, such as bitter almonds and peaches. It is a medically interesting but controversial compound as it has anticancer activity [...] Read more.
Amygdalin (d-Mandelonitrile 6-O-β-d-glucosido-β-d-glucoside) is a natural cyanogenic glycoside occurring in the seeds of some edible plants, such as bitter almonds and peaches. It is a medically interesting but controversial compound as it has anticancer activity on one hand and can be toxic via enzymatic degradation and production of hydrogen cyanide on the other hand. Despite numerous contributions on cancer cell lines, the clinical evidence for the anticancer activity of amygdalin is not fully confirmed. Moreover, high dose exposures to amygdalin can produce cyanide toxicity. The aim of this review is to present the current state of knowledge on the sources, toxicity and anticancer properties of amygdalin, and analytical methods for its determination in plant seeds. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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20 pages, 3990 KiB  
Review
Nanomaterials in Cementitious Composites: An Update
by Zoi S. Metaxa, Athanasia K. Tolkou, Stefania Efstathiou, Abbas Rahdar, Evangelos P. Favvas, Athanasios C. Mitropoulos and George Z. Kyzas
Molecules 2021, 26(5), 1430; https://doi.org/10.3390/molecules26051430 - 06 Mar 2021
Cited by 36 | Viewed by 3444
Abstract
This review is an update about the addition of nanomaterials in cementitious composites in order to improve their performance. The most common used nanomaterials for cementitious materials are carbon nanotubes, nanocellulose, nanographene, graphene oxide, nanosilica and nanoTiO2. All these nanomaterials can [...] Read more.
This review is an update about the addition of nanomaterials in cementitious composites in order to improve their performance. The most common used nanomaterials for cementitious materials are carbon nanotubes, nanocellulose, nanographene, graphene oxide, nanosilica and nanoTiO2. All these nanomaterials can improve the physical, mechanical, thermal and electrical properties of cementitious composites, for example increase their compressive and tensile strength, accelerate hydration, decrease porosity and enhance fire resistance. Cement based materials have a very complex nanostructure consisting of hydration products, crystals, unhydrated cement particles and nanoporosity where traditional reinforcement, which is at the macro and micro scale, is not effective. Nanomaterials can reinforce the nanoscale, which wasn’t possible heretofore, enhancing the performance of the cementitious matrix. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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19 pages, 2743 KiB  
Review
Progress in the Application of Nanoparticles and Graphene as Drug Carriers and on the Diagnosis of Brain Infections
by Mahmood Barani, Mahwash Mukhtar, Abbas Rahdar, Ghasem Sargazi, Anna Thysiadou and George Z. Kyzas
Molecules 2021, 26(1), 186; https://doi.org/10.3390/molecules26010186 - 02 Jan 2021
Cited by 51 | Viewed by 6043
Abstract
The blood–brain barrier (BBB) is the protective sheath around the brain that protects the sensitive microenvironments of the brain. However, certain pathogens, viruses, and bacteria disrupt the endothelial barrier and cause infection and hence inflammation in meninges. Macromolecular therapeutics are unable to cross [...] Read more.
The blood–brain barrier (BBB) is the protective sheath around the brain that protects the sensitive microenvironments of the brain. However, certain pathogens, viruses, and bacteria disrupt the endothelial barrier and cause infection and hence inflammation in meninges. Macromolecular therapeutics are unable to cross the tight junctions, thereby limiting their bioavailability in the brain. Recently, nanotechnology has brought a revolution in the field of drug delivery in brain infections. The nanostructures have high targeting accuracy and specificity to the receptors in the case of active targeting, which have made them the ideal cargoes to permeate across the BBB. In addition, nanomaterials with biomimetic functions have been introduced to efficiently cross the BBB to be engulfed by the pathogens. This review focuses on the nanotechnology-based drug delivery approaches for exploration in brain infections, including meningitis. Viruses, bacteria, fungi, or, rarely, protozoa or parasites may be the cause of brain infections. Moreover, inflammation of the meninges, called meningitis, is presently diagnosed using laboratory and imaging tests. Despite attempts to improve diagnostic instruments for brain infections and meningitis, due to its complicated and multidimensional nature and lack of successful diagnosis, meningitis appears almost untreatable. Potential for overcoming the difficulties and limitations related to conventional diagnostics has been shown by nanoparticles (NPs). Nanomedicine now offers new methods and perspectives to improve our knowledge of meningitis and can potentially give meningitis patients new hope. Here, we review traditional diagnosis tools and key nanoparticles (Au-NPs, graphene, carbon nanotubes (CNTs), QDs, etc.) for early diagnosis of brain infections and meningitis. Full article
(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Applied Chemistry)
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