Molecules

22 pages, 7300 KiB

Open AccessArticle

Modular Breath Analyzer (MBA): Introduction of a Breath Analyzer Platform Based on an Innovative and Unique, Modular eNose Concept for Breath Diagnostics and Utilization of Calibration Transfer Methods in Breath Analysis Studies

by Carsten Jaeschke, Marta Padilla, Johannes Glöckler, Inese Polaka, Martins Leja, Viktors Veliks, Jan Mitrovics, Marcis Leja and Boris Mizaikoff

Molecules 2021, 26(12), 3776; https://doi.org/10.3390/molecules26123776 - 21 Jun 2021

Cited by 4 | Viewed by 3315

Abstract

Exhaled breath analysis for early disease detection may provide a convenient method for painless and non-invasive diagnosis. In this work, a novel, compact and easy-to-use breath analyzer platform with a modular sensing chamber and direct breath sampling unit is presented. The developed analyzer [...] Read more.

Exhaled breath analysis for early disease detection may provide a convenient method for painless and non-invasive diagnosis. In this work, a novel, compact and easy-to-use breath analyzer platform with a modular sensing chamber and direct breath sampling unit is presented. The developed analyzer system comprises a compact, low volume, temperature-controlled sensing chamber in three modules that can host any type of resistive gas sensor arrays. Furthermore, in this study three modular breath analyzers are explicitly tested for reproducibility in a real-life breath analysis experiment with several calibration transfer (CT) techniques using transfer samples from the experiment. The experiment consists of classifying breath samples from 15 subjects before and after eating a specific meal using three instruments. We investigate the possibility to transfer calibration models across instruments using transfer samples from the experiment under study, since representative samples of human breath at some conditions are difficult to simulate in a laboratory. For example, exhaled breath from subjects suffering from a disease for which the biomarkers are mostly unknown. Results show that many transfer samples of all the classes under study (in our case meal/no meal) are needed, although some CT methods present reasonably good results with only one class. Full article

(This article belongs to the Special Issue Recent Advances in Volatile Organic Compound Analysis as Diagnostic Biomarkers)

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15 pages, 3802 KiB

Open AccessArticle

Targeting 3CLpro and SARS-CoV-2 RdRp by Amphimedon sp. Metabolites: A Computational Study

by Nourhan Hisham Shady, Alaa M. Hayallah, Mamdouh F. A. Mohamed, Mohammed M. Ghoneim, Garri Chilingaryan, Mohammad M. Al-Sanea, Mostafa A. Fouad, Mohamed Salah Kamel and Usama Ramadan Abdelmohsen

Molecules 2021, 26(12), 3775; https://doi.org/10.3390/molecules26123775 - 21 Jun 2021

Cited by 6 | Viewed by 3149

Abstract

Since December 2019, novel coronavirus disease 2019 (COVID-19) pandemic has caused tremendous economic loss and serious health problems worldwide. In this study, we investigated 14 natural compounds isolated from Amphimedon sp. via a molecular docking study, to examine their ability to act as [...] Read more.

Since December 2019, novel coronavirus disease 2019 (COVID-19) pandemic has caused tremendous economic loss and serious health problems worldwide. In this study, we investigated 14 natural compounds isolated from Amphimedon sp. via a molecular docking study, to examine their ability to act as anti-COVID-19 agents. Moreover, the pharmacokinetic properties of the most promising compounds were studied. The docking study showed that virtually screened compounds were effective against the new coronavirus via dual inhibition of SARS-CoV-2 RdRp and the 3CL main protease. In particular, nakinadine B (1), 20-hepacosenoic acid (11) and amphimedoside C (12) were the most promising compounds, as they demonstrated good interactions with the pockets of both enzymes. Based on the analysis of the molecular docking results, compounds 1 and 12 were selected for molecular dynamics simulation studies. Our results showed Amphimedon sp. to be a rich source for anti-COVID-19 metabolites. Full article

(This article belongs to the Special Issue Molecular Docking in Drug Discovery)

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14 pages, 1026 KiB

Open AccessArticle

Preservative Effect of Aqueous and Ethanolic Extracts of the Macroalga Bifurcaria bifurcata on the Quality of Chilled Hake (Merluccius merluccius)

by José M. Miranda, Bin Zhang, Jorge Barros-Velázquez and Santiago P. Aubourg

Molecules 2021, 26(12), 3774; https://doi.org/10.3390/molecules26123774 - 21 Jun 2021

Cited by 7 | Viewed by 2034

Abstract

This work addressed the preservative behaviour of different icing media containing extracts from the alga Bifurcaria bifurcata. A comparative study of the antimicrobial and antioxidant effects of aqueous and ethanolic extracts of this macroalga was carried out. Whole hake (Merluccius merluccius [...] Read more.

This work addressed the preservative behaviour of different icing media containing extracts from the alga Bifurcaria bifurcata. A comparative study of the antimicrobial and antioxidant effects of aqueous and ethanolic extracts of this macroalga was carried out. Whole hake (Merluccius merluccius) pieces were stored in ice containing either kind of extract and analysed for quality changes throughout a 13-day storage period. A progressive loss of microbial and biochemical quality was detected in all batches as chilling time increased. A significant inhibitory effect (p < 0.05) on microbial activity could be observed as a result of including the aqueous (lowering of psychrotrophic and lipolytic counts and pH value) and ethanolic (lowering of psychrotrophic and lipolytic counts) extracts. Additionally, both kinds of extract led to a substantial inhibition (p < 0.05) in the lipid hydrolysis rate (formation of free fatty acids), greater in the case of the batch containing ethanolic extract. Concerning lipid oxidation, a similar inhibitory effect (p < 0.05) on the formation of secondary compounds (thiobarbituric acid substances) was noticed in fish specimens corresponding to both alga extracts; however, more (p < 0.05) peroxide formation was detected in fish corresponding to the ethanolic extract batch. A preservative effect can be concluded for both kinds of extract; this effect agrees with previous studies reporting the presence of hydrophilic and lipophilic bioactive compounds in B. bifurcata. Full article

(This article belongs to the Special Issue Antioxidants in Multiphase Systems)

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10 pages, 1070 KiB

Open AccessArticle

The Additive Influence of Propane-1,2-Diol on SDS Micellar Structure and Properties

by Martina Gudelj, Paola Šurina, Lucija Jurko, Ante Prkić and Perica Bošković

Molecules 2021, 26(12), 3773; https://doi.org/10.3390/molecules26123773 - 21 Jun 2021

Cited by 8 | Viewed by 2576

Abstract

Micellar systems are colloids with significant properties for pharmaceutical and food applications. They can be used to formulate thermodynamically stable mixtures to solubilize hydrophobic food-related substances. Furthermore, micellar formation is a complex process in which a variety of intermolecular interactions determine the course [...] Read more.

Micellar systems are colloids with significant properties for pharmaceutical and food applications. They can be used to formulate thermodynamically stable mixtures to solubilize hydrophobic food-related substances. Furthermore, micellar formation is a complex process in which a variety of intermolecular interactions determine the course of formation and most important are the hydrophobic and hydrophilic interactions between surfactant–solvent and solvent–solvent. Glycols are organic compounds that belong to the group of alcohols. Among them, propane-1,2-diol (PG) is a substance commonly used as a food additive or ingredient in many cosmetic and hygiene products. The nature of the additive influences the micellar structure and properties of sodium dodecyl sulfate (SDS). When increasing the mass fraction of propane-1,2-diol in binary mixtures, the c.m.c. values decrease because propane-1,2-diol is a polar solvent, which gives it the ability to form hydrogen bonds, decreasing the cohesivity of water and reducing the dielectric constant of the aqueous phase. The values of

Δ G_{m}^{0}

are negative in all mixed solvents according to the reduction in solvophobic interactions and increase in electrostatic interaction. With the rising concentration of cosolvent, the equilibrium between cosolvent in bulk solution and in the formed micelles is on the side of micelles, leading to the formation of micelles at a lower concentration with a small change in micellar size. According to the ¹H NMR, with the addition of propylene glycol, there is a slight shift of SDS peaks towards lower ppm regions in comparison to the D₂O peak. The shift is more evident with the increase in the amount of added propane-1,2-diol in comparison to the NMR spectra of pure SDS. Addition of propane-1,2-diol causes the upfield shift of the protons associated with hydrophilic groups, causing the shielding effect. This signifies that the alcohol is linked with the polar head groups of SDS due to its proximity to the SDS molecules. Full article

(This article belongs to the Special Issue Cutting-Edge Physical Chemistry Research in Europe)

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27 pages, 20774 KiB

Open AccessArticle

Computational Insights on the Potential of Some NSAIDs for Treating COVID-19: Priority Set and Lead Optimization

by Ayman Abo Elmaaty, Mohammed I. A. Hamed, Muhammad I. Ismail, Eslam B. Elkaeed, Hamada S. Abulkhair, Muhammad Khattab and Ahmed A. Al-Karmalawy

Molecules 2021, 26(12), 3772; https://doi.org/10.3390/molecules26123772 - 21 Jun 2021

Cited by 62 | Viewed by 4728

Abstract

The discovery of drugs capable of inhibiting SARS-CoV-2 is a priority for human beings due to the severity of the global health pandemic caused by COVID-19. To this end, repurposing of FDA-approved drugs such as NSAIDs against COVID-19 can provide therapeutic alternatives that [...] Read more.

The discovery of drugs capable of inhibiting SARS-CoV-2 is a priority for human beings due to the severity of the global health pandemic caused by COVID-19. To this end, repurposing of FDA-approved drugs such as NSAIDs against COVID-19 can provide therapeutic alternatives that could be utilized as an effective safe treatment for COVID-19. The anti-inflammatory activity of NSAIDs is also advantageous in the treatment of COVID-19, as it was found that SARS-CoV-2 is responsible for provoking inflammatory cytokine storms resulting in lung damage. In this study, 40 FDA-approved NSAIDs were evaluated through molecular docking against the main protease of SARS-CoV-2. Among the tested compounds, sulfinpyrazone 2, indomethacin 3, and auranofin 4 were proposed as potential antagonists of COVID-19 main protease. Molecular dynamics simulations were also carried out for the most promising members of the screened NSAID candidates (2, 3, and 4) to unravel the dynamic properties of NSAIDs at the target receptor. The conducted quantum mechanical study revealed that the hybrid functional B3PW91 provides a good description of the spatial parameters of auranofin 4. Interestingly, a promising structure–activity relationship (SAR) was concluded from our study that could help in the future design of potential SARS-CoV-2 main protease inhibitors with expected anti-inflammatory effects as well. NSAIDs may be used by medicinal chemists as lead compounds for the development of potent SARS-CoV-2 (M^pro) inhibitors. In addition, some NSAIDs can be selectively designated for treatment of inflammation resulting from COVID-19. Full article

(This article belongs to the Special Issue Molecular Modeling: Advancements and Applications)

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27 pages, 3551 KiB

Open AccessReview

Formulation Improvements in the Applications of Surfactant–Oil–Water Systems Using the HLD_N Approach with Extended Surfactant Structure

by Ana M. Forgiarini, Ronald Marquez and Jean-Louis Salager

Molecules 2021, 26(12), 3771; https://doi.org/10.3390/molecules26123771 - 21 Jun 2021

Cited by 30 | Viewed by 5117

Abstract

Soap applications for cleaning and personal care have been used for more than 4000 years, dating back to the pharaonic period, and have widely proliferated with the appearance of synthetic surfactants a century ago. Synthetic surfactants used to make macro-micro-nano-emulsions and foams are [...] Read more.

Soap applications for cleaning and personal care have been used for more than 4000 years, dating back to the pharaonic period, and have widely proliferated with the appearance of synthetic surfactants a century ago. Synthetic surfactants used to make macro-micro-nano-emulsions and foams are used in laundry and detergency, cosmetics and pharmaceuticals, food conditioning, emulsified paints, explosives, enhanced oil recovery, wastewater treatment, etc. The introduction of a multivariable approach such as the normalized hydrophilic–lipophilic deviation (HLD _N) and of specific structures, tailored with an intramolecular extension to increase solubilization (the so-called extended surfactants), makes it possible to improve the results and performance in surfactant–oil–water systems and their applications. This article aims to present an up-to-date overview of extended surfactants. We first present an introduction regarding physicochemical formulation and its relationship with performance. The second part deals with the importance of HLD _N to make a straightforward classification according to the type of surfactants and how formulation parameters can be used to understand the need for an extension of the molecule reach into the oil and water phases. Then, extended surfactant characteristics and strategies to increase performance are outlined. Finally, two specific applications, i.e., drilling fluids and crude oil dewatering, are described. Full article

(This article belongs to the Special Issue Functional Colloids for Advanced Nanomaterials and Composites: From Theory to Applications)

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18 pages, 1115 KiB

Open AccessReview

Bioactives from Bee Products and Accompanying Extracellular Vesicles as Novel Bioactive Components for Wound Healing

by Željka Peršurić and Sandra Kraljević Pavelić

Molecules 2021, 26(12), 3770; https://doi.org/10.3390/molecules26123770 - 21 Jun 2021

Cited by 16 | Viewed by 6585

Abstract

In recent years, interest has surged among researchers to determine compounds from bee products such as honey, royal jelly, propolis and bee pollen, which are beneficial to human health. Mass spectrometry techniques have shown that bee products contain a number of proven health-promoting [...] Read more.

In recent years, interest has surged among researchers to determine compounds from bee products such as honey, royal jelly, propolis and bee pollen, which are beneficial to human health. Mass spectrometry techniques have shown that bee products contain a number of proven health-promoting compounds but also revealed rather high diversity in the chemical composition of bee products depending on several factors, such as for example botanical sources and geographical origin. In the present paper, we present recent scientific advances in the field of major bioactive compounds from bee products and corresponding regenerative properties. We also discuss extracellular vesicles from bee products as a potential novel bioactive nutraceutical component. Extracellular vesicles are cell-derived membranous structures that show promising potential in various therapeutic areas. It has been extensively reported that the use of vesicles, which are naturally formed in plant and animal cells, as delivery agents have many advantages. Whether the use of extracellular vesicles from bee products represents a new solution for wound healing remains still to be elucidated. However, promising results in specific applications of the bee products in wound healing and tissue regenerative properties of extracellular vesicles provide a good rationale to further explore this idea. Full article

(This article belongs to the Special Issue 25th Anniversary of Molecules—Advances in Food Chemistry, Nutraceuticals, Functional Foods, and Dietary Bioactives: Celebrating the Lifetime Achievements of Professor Fereidoon Shahidi)

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12 pages, 3270 KiB

Open AccessArticle

High Pressure Processing Impact on Alternariol and Aflatoxins of Grape Juice and Fruit Juice-Milk Based Beverages

by Noelia Pallarés, Albert Sebastià, Vicente Martínez-Lucas, Mario González-Angulo, Francisco J. Barba, Houda Berrada and Emilia Ferrer

Molecules 2021, 26(12), 3769; https://doi.org/10.3390/molecules26123769 - 21 Jun 2021

Cited by 13 | Viewed by 3753

Abstract

High-pressure processing (HPP) has emerged over the last 2 decades as a good alternative to traditional thermal treatment for food safety and shelf-life extension, supplying foods with similar characteristics to those of fresh products. Currently, HPP has also been proposed as a useful [...] Read more.

High-pressure processing (HPP) has emerged over the last 2 decades as a good alternative to traditional thermal treatment for food safety and shelf-life extension, supplying foods with similar characteristics to those of fresh products. Currently, HPP has also been proposed as a useful tool to reduce food contaminants, such as pesticides and mycotoxins. The aim of the present study is to explore the effect of HPP technology at 600 MPa during 5 min at room temperature on alternariol (AOH) and aflatoxin B1 (AFB1) mycotoxins reduction in different juice models. The effect of HPP has also been compared with a thermal treatment performed at 90 °C during 21 s. For this, different juice models, orange juice/milk beverage, strawberry juice/milk beverage and grape juice, were prepared and spiked individually with AOH and AFB1 at a concentration of 100 µg/L. After HPP and thermal treatments, mycotoxins were extracted from treated samples and controls by dispersive liquid–liquid microextraction (DLLME) and determined by HPLC-MS/MS-IT. The results obtained revealed reduction percentages up to 24% for AFB1 and 37% for AOH. Comparing between different juice models, significant differences were observed for AFB1 residues in orange juice/milk versus strawberry juice/milk beverages after HPP treatment. Moreover, HPP resulted as more effective than thermal treatment, being an effective tool to incorporate to food industry in order to reach mycotoxins reductions. Full article

(This article belongs to the Special Issue Advances in High Pressure Processing on Foods)

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2 pages, 172 KiB

Open AccessEditorial

25th Anniversary of Molecules—Recent Advances in Green Chemistry

by Gonzalo de Gonzalo and Mara G. Freire

Molecules 2021, 26(12), 3768; https://doi.org/10.3390/molecules26123768 - 21 Jun 2021

Viewed by 1790

Abstract

Green Chemistry has been defined by the EPA as the design of chemical products and processes that reduce or eliminate the use or generation of hazardous substances [...] Full article

(This article belongs to the Special Issue 25th Anniversary of Molecules—Recent Advances in Green Chemistry)

15 pages, 2346 KiB

Open AccessArticle

Presence of Cholesterol in Non-Animal Organisms: Identification and Quantification of Cholesterol in Crude Seed Oil from Perilla frutescens and Dehydrated Pyropia tenera

by Min-Ji Oh, Hee-Jin So, Eun-Sik Hong, Jung-Ah Shin and Ki-Teak Lee

Molecules 2021, 26(12), 3767; https://doi.org/10.3390/molecules26123767 - 21 Jun 2021

Cited by 5 | Viewed by 2646

Abstract

Studies have reported that cholesterol, a molecule found mainly in animals, is also present in some plants and algae. This study aimed to determine whether cholesterol exists in three dehydrated algae species, namely, Pyropia tenera, Saccharina japonica, and Undaria pinnatifida, and in [...] Read more.

Studies have reported that cholesterol, a molecule found mainly in animals, is also present in some plants and algae. This study aimed to determine whether cholesterol exists in three dehydrated algae species, namely, Pyropia tenera, Saccharina japonica, and Undaria pinnatifida, and in one plant species, namely, Perilla frutescens (four perilla seed oil samples were analyzed). These species were chosen for investigation because they are common ingredients in East Asian cuisine. Gas chromatography-flame ionization detection (GC-FID) analysis found that cholesterol was present in P. tenera (14.6 mg/100 g) and in all four perilla seed oil samples (0.3–0.5 mg/100 g). High-performance liquid chromatography with evaporative light-scattering detection (HPLC-ELSD) also demonstrated that cholesterol was present in P. tenera (14.2 mg/100 g) and allowed the separation of cholesterol from its isomer lathosterol. However, cholesterol could not be detected by HPLC-ELSD in the perilla seed oil samples, most likely because it is only present in trace amounts. Moreover, liquid chromatography-tandem mass spectrometry (LC-MS/MS) confirmed the presence of cholesterol in both P. tenera and perilla seed oil. MRM results further suggested that lathosterol (a precursor of cholesterol) was present in P. tenera. Full article

(This article belongs to the Special Issue Biocompounds and Functional Molecules Derived from Lipids)

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12 pages, 1971 KiB

Open AccessArticle

Rutin and Quercetin Decrease Cholesterol in HepG2 Cells but Not Plasma Cholesterol in Hamsters by Oral Administration

by Ning Liang, Yuk-Man Li, Zouyan He, Wangjun Hao, Yimin Zhao, Jianhui Liu, Hanyue Zhu, Erika Kwek, Ka-Ying Ma, Wen-Sen He and Zhen-Yu Chen

Molecules 2021, 26(12), 3766; https://doi.org/10.3390/molecules26123766 - 21 Jun 2021

Cited by 10 | Viewed by 3565

Abstract

Rutin (R) and quercetin (Q) are two widespread dietary flavonoids. Previous studies regarding the plasma cholesterol-lowering activity of R and Q generated inconsistent results. The present study was therefore carried out to investigate the effects of R and Q on cholesterol metabolism in [...] Read more.

Rutin (R) and quercetin (Q) are two widespread dietary flavonoids. Previous studies regarding the plasma cholesterol-lowering activity of R and Q generated inconsistent results. The present study was therefore carried out to investigate the effects of R and Q on cholesterol metabolism in both HepG2 cells and hypercholesterolemia hamsters. Results from HepG2 cell experiments demonstrate that both R and Q decreased cholesterol at doses of 5 and 10 µM. R and Q up-regulated both the mRNA and protein expression of sterol regulatory element binding protein 2 (SREBP2), low-density lipoprotein receptor (LDLR), and liver X receptor alpha (LXRα). The immunofluorescence study revealed that R and Q increased the LDLR expression, while only Q improved LDL-C uptake in HepG2 cells. Results from hypercholesterolemia hamsters fed diets containing R (5.5 g/kg diet) and Q (2.5 g/kg diet) for 8 weeks demonstrate that both R and Q had no effect on plasma total cholesterol. In the liver, only Q reduced cholesterol significantly. The discrepancy between the in vitro and in vivo studies was probably due to a poor bioavailability of flavonoids in the intestine. It was therefore concluded that R and Q were effective in reducing cholesterol in HepG2 cells in vitro, whereas in vivo, the oral administration of the two flavonoids had little effect on plasma cholesterol in hamsters. Full article

(This article belongs to the Special Issue 25th Anniversary of Molecules—Advances in Food Chemistry, Nutraceuticals, Functional Foods, and Dietary Bioactives: Celebrating the Lifetime Achievements of Professor Fereidoon Shahidi)

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15 pages, 2106 KiB

Open AccessArticle

Molecular Human Targets of Bioactive Alkaloid-Type Compounds from Tabernaemontana cymose Jacq.

by Andrés Oliveros-Díaz, Jesús Olivero-Verbel, Yina Pájaro-González and Fredyc Díaz-Castillo

Molecules 2021, 26(12), 3765; https://doi.org/10.3390/molecules26123765 - 21 Jun 2021

Cited by 7 | Viewed by 3237

Abstract

Alkaloids are a group of secondary metabolites that have been widely studied for the discovery of new drugs due to their properties on the central nervous system and their anti-inflammatory, antioxidant and anti-cancer activities. Molecular docking was performed for 10 indole alkaloids identified [...] Read more.

Alkaloids are a group of secondary metabolites that have been widely studied for the discovery of new drugs due to their properties on the central nervous system and their anti-inflammatory, antioxidant and anti-cancer activities. Molecular docking was performed for 10 indole alkaloids identified in the ethanol extract of Tabernaemontana cymosa Jacq. with 951 human targets involved in different diseases. The results were analyzed through the KEGG and STRING databases, finding the most relevant physiological associations for alkaloids. The molecule 5-oxocoronaridine proved to be the most active molecule against human proteins (binding energy affinity average = −9.2 kcal/mol) and the analysis of the interactions between the affected proteins pointed to the PI3K/ Akt/mTOR signaling pathway as the main target. The above indicates that indole alkaloids from T. cymosa constitute a promising source for the search and development of new treatments against different types of cancer. Full article

(This article belongs to the Section Computational and Theoretical Chemistry)

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13 pages, 4070 KiB

Open AccessArticle

Hydration Kinetics for Alkaline Activation of Slag from Color Variation Data

by Zhaoyang Ding, Jinghai Zhou, Qun Su, Hong Sun, Yichao Zhang, Qing Wang, Hongguang Bian and Fengxin Dong

Molecules 2021, 26(12), 3764; https://doi.org/10.3390/molecules26123764 - 21 Jun 2021

Cited by 4 | Viewed by 1907

Abstract

In this study, we explore a new method based on color variation data to derive the kinetics of the entire process of the hydration of alkali-activated slag (AAS). Using this image analysis technique, we can monitor the induction period that cannot be observed [...] Read more.

In this study, we explore a new method based on color variation data to derive the kinetics of the entire process of the hydration of alkali-activated slag (AAS). Using this image analysis technique, we can monitor the induction period that cannot be observed using conventional microcalorimetry techniques. Color variation was recorded across a sequence of 9999 images, which were processed via MATLAB software package. Further, an average pixel value (APV) was determined to represent the color in each image. Reaction parameters, such as color variation velocity v(t), reaction speed ε(t), and hydration degree α(t), that govern the entire hydration process were determined. On the basis of the reaction parameters and a Krstulovic–Dabic kinetic model, integral and differential equations were derived to simulate the three basic processes of AAS hydration. Equations describing the reaction kinetics of AAS with solutions of three different concentrations of NaOH were extracted using this method. Full article

(This article belongs to the Special Issue Novel Cementitious Materials)

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24 pages, 9742 KiB

Open AccessReview

NMR of Natural Products as Potential Drugs

by Poul Erik Hansen

Molecules 2021, 26(12), 3763; https://doi.org/10.3390/molecules26123763 - 21 Jun 2021

Cited by 10 | Viewed by 4095

Abstract

This review outlines methods to investigate the structure of natural products with emphasis on intramolecular hydrogen bonding, tautomerism and ionic structures using NMR techniques. The focus is on 1H chemical shifts, isotope effects on chemical shifts and diffusion ordered spectroscopy. In addition, density [...] Read more.

This review outlines methods to investigate the structure of natural products with emphasis on intramolecular hydrogen bonding, tautomerism and ionic structures using NMR techniques. The focus is on 1H chemical shifts, isotope effects on chemical shifts and diffusion ordered spectroscopy. In addition, density functional theory calculations are performed to support NMR results. The review demonstrates how hydrogen bonding may lead to specific structures and how chemical equilibria, as well as tautomeric equilibria and ionic structures, can be detected. All these features are important for biological activity and a prerequisite for correct docking experiments and future use as drugs. Full article

(This article belongs to the Special Issue Featured Reviews in Applied Chemistry)

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21 pages, 1871 KiB

Open AccessReview

Nutraceuticals and Enteric Glial Cells

by Laura López-Gómez, Agata Szymaszkiewicz, Marta Zielińska and Raquel Abalo

Molecules 2021, 26(12), 3762; https://doi.org/10.3390/molecules26123762 - 21 Jun 2021

Cited by 9 | Viewed by 4042

Abstract

Until recently, glia were considered to be a structural support for neurons, however further investigations showed that glial cells are equally as important as neurons. Among many different types of glia, enteric glial cells (EGCs) found in the gastrointestinal tract, have been significantly [...] Read more.

Until recently, glia were considered to be a structural support for neurons, however further investigations showed that glial cells are equally as important as neurons. Among many different types of glia, enteric glial cells (EGCs) found in the gastrointestinal tract, have been significantly underestimated, but proved to play an essential role in neuroprotection, immune system modulation and many other functions. They are also said to be remarkably altered in different physiopathological conditions. A nutraceutical is defined as any food substance or part of a food that provides medical or health benefits, including prevention and treatment of the disease. Following the description of these interesting peripheral glial cells and highlighting their role in physiological and pathological changes, this article reviews all the studies on the effects of nutraceuticals as modulators of their functions. Currently there are only a few studies available concerning the effects of nutraceuticals on EGCs. Most of them evaluated molecules with antioxidant properties in systemic conditions, whereas only a few studies have been performed using models of gastrointestinal disorders. Despite the scarcity of studies on the topic, all agree that nutraceuticals have the potential to be an interesting alternative in the prevention and/or treatment of enteric gliopathies (of systemic or local etiology) and their associated gastrointestinal conditions. Full article

(This article belongs to the Special Issue Nutraceuticals in Immune Function)

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13 pages, 2460 KiB

Open AccessArticle

Kinetic Study on Chlorophyll and Antioxidant Activity from Polyscias fruticosa (L.) Harms Leaves via Microwave-Assisted Extraction

by Thi-Thuy-Dung Nguyen, Quoc-Duy Nguyen and Thi-Van-Linh Nguyen

Molecules 2021, 26(12), 3761; https://doi.org/10.3390/molecules26123761 - 21 Jun 2021

Cited by 9 | Viewed by 3949

Abstract

Polyscias fruticosa (L.) leaves contain significant bioactive compounds with high antioxidant activity such as chlorophylls, total polyphenols, etc. but these have still been underutilized. In this study, the kinetics of chlorophyll and antioxidant activity extraction from P. fruticosa leaves by microwave-assisted extraction (MAE) [...] Read more.

Polyscias fruticosa (L.) leaves contain significant bioactive compounds with high antioxidant activity such as chlorophylls, total polyphenols, etc. but these have still been underutilized. In this study, the kinetics of chlorophyll and antioxidant activity extraction from P. fruticosa leaves by microwave-assisted extraction (MAE) were investigated. Microwave power was 300, 450, or 600 (W); the ratio of material/solvent varied from 1:40 to 1:80 (g/mL). In this study, the second-order kinetic model successfully predicted the change of chlorophyll and antioxidant activity during MAE. The increase of microwave power or/and the solvent amount increased saturated extraction efficiency and the extraction rate constant. However, the saturated concentration of chlorophyll and antioxidant activity increased with the increment of microwave power and the decrease in solvent amount. Full article

(This article belongs to the Special Issue Bioactive Compounds and Antioxidant Activity of Extracts from Different Natural Plants)

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11 pages, 2207 KiB

Open AccessArticle

The Fumarprotocetraric Acid Inhibits Tau Covalently, Avoiding Cytotoxicity of Aggregates in Cells

by Camila González, Constanza Cartagena, Leonardo Caballero, Francisco Melo, Carlos Areche and Alberto Cornejo

Molecules 2021, 26(12), 3760; https://doi.org/10.3390/molecules26123760 - 21 Jun 2021

Cited by 10 | Viewed by 2684

Abstract

Neurodegenerative disorders, including Tauopathies that involve tau protein, base their pathological mechanism on forming proteinaceous aggregates, which has a deleterious effect on cells triggering an inflammatory response. Moreover, tau inhibitors can exert their mechanism of action through noncovalent and covalent interactions. Thus, Michael’s [...] Read more.

Neurodegenerative disorders, including Tauopathies that involve tau protein, base their pathological mechanism on forming proteinaceous aggregates, which has a deleterious effect on cells triggering an inflammatory response. Moreover, tau inhibitors can exert their mechanism of action through noncovalent and covalent interactions. Thus, Michael’s addition appears as a feasible type of interaction involving an α, β unsaturated carbonyl moiety to avoid pathological confirmation and further cytotoxicity. Moreover, we isolated three compounds from Antarctic lichens Cladonia cariosa and Himantormia lugubris: protolichesterinic acid (1), fumarprotocetraric acid (2), and lichesterinic acid (3). The maleimide cysteine labeling assay showed that compounds 1, 2, and 3 inhibit at 50 µM, but compounds 2 and 3 are statistically significant. Based on its inhibition capacity, we decided to test compound 2 further. Thus, our results suggest that compound 2 remodel soluble oligomers and diminish β sheet content, as demonstrated through ThT experiments. Hence, we added externally treated oligomers with compound 2 to demonstrate that they are harmless in cell culture. First, the morphology of cells in the presence of aggregates does not suffer evident changes compared to the control. Additionally, the externally added aggregates do not provoke a substantial LDH release compared to the control, indicating that treated oligomers do not provoke membrane damage in cell culture compared with aggregates alone. Thus, in the present work, we demonstrated that Michael’s acceptors found in lichens could serve as a scaffold to explore different mechanisms of action to turn tau aggregates into harmless species. Full article

(This article belongs to the Special Issue Synthesis and Identification of Small Compounds Active in Neurodegeneration)

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11 pages, 4128 KiB

Open AccessArticle

Imaging and SERS Study of the Au Nanoparticles Interaction with HPV and Carcinogenic Cervical Tissues

by Andrea Ceja-Fdez, Ramon Carriles, Ana Lilia González-Yebra, Juan Vivero-Escoto, Elder de la Rosa and Tzarara López-Luke

Molecules 2021, 26(12), 3758; https://doi.org/10.3390/molecules26123758 - 20 Jun 2021

Cited by 6 | Viewed by 3013

Abstract

In this work, gold NPs were prepared by the Turkevich method, and their interaction with HPV and cancerous cervical tissues were studied by scanning electron microscopy, energy-dispersive x-ray spectroscopy, confocal and multiphoton microscopy and SERS. The SEM images confirmed the presence and localization [...] Read more.

In this work, gold NPs were prepared by the Turkevich method, and their interaction with HPV and cancerous cervical tissues were studied by scanning electron microscopy, energy-dispersive x-ray spectroscopy, confocal and multiphoton microscopy and SERS. The SEM images confirmed the presence and localization of the gold NPs inside of the two kinds of tissues. The light absorption of the gold NPs was at 520 nm. However, it was possible to obtain two-photon imaging (red emission region) of the gold NPs inside of the tissue, exciting the samples at 900 nm, observing the morphology of the tissues. The infrared absorption was probably due to the aggregation of gold NPs inside the tissues. Therefore, through the interaction of gold nanoparticles with the HPV and cancerous cervical tissues, a surface enhanced Raman spectroscopy (SERS) was obtained. As preliminary studies, having an average of 1000 Raman spectra per tissue, SERS signals showed changes between the HPV-infected and the carcinogenic tissues; these spectral signatures occurred mainly in the DNA bands, potentially offering a tool for the rapid screening of cancer. Full article

(This article belongs to the Special Issue Photosensitizer: Design, Characteriazation and Application)

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7 pages, 794 KiB

Open AccessCommunication

Biosensing Membrane Base on Ferulic Acid and Glucose Oxidase for an Amperometric Glucose Biosensor

by Gabriela Valdés-Ramírez and Laura Galicia

Molecules 2021, 26(12), 3757; https://doi.org/10.3390/molecules26123757 - 20 Jun 2021

Cited by 6 | Viewed by 2656

Abstract

A biosensing membrane base on ferulic acid and glucose oxidase is synthesized onto a carbon paste electrode by electropolymerization via cyclic voltammetry in aqueous media at neutral pH at a single step. The developed biosensors exhibit a linear response from 0.082 to 34 [...] Read more.

A biosensing membrane base on ferulic acid and glucose oxidase is synthesized onto a carbon paste electrode by electropolymerization via cyclic voltammetry in aqueous media at neutral pH at a single step. The developed biosensors exhibit a linear response from 0.082 to 34 mM glucose concentration, with a coefficient of determination R² equal to 0.997. The biosensors display a sensitivity of 1.1 μAmM⁻¹ cm⁻², a detection limit of 0.025 mM, and 0.082 mM as glucose quantification limit. The studies reveal stable, repeatable, and reproducible biosensors response. The results indicate that the novel poly-ferulic acid membrane synthesized by electropolymerization is a promising method for glucose oxidase immobilization towards the development of glucose biosensors. The developed glucose biosensors exhibit a broader linear glucose response than other polymer-based glucose biosensors. Full article

(This article belongs to the Special Issue Electrochemical Sensors and Biosensors for Food, Pharmaceutical Analysis and for Detection of Molecules of Biological and Clinical Interest)

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16 pages, 3992 KiB

Open AccessArticle

Frequency-Dependent Sonochemical Processing of Silicon Surfaces in Tetrahydrofuran Studied by Surface Photovoltage Transients

by Artem Podolian, Andriy Nadtochiy, Oleg Korotchenkov and Viktor Schlosser

Molecules 2021, 26(12), 3756; https://doi.org/10.3390/molecules26123756 - 20 Jun 2021

Viewed by 2209

Abstract

The field of chemical and physical transformations induced by ultrasonic waves has shown steady progress during the past decades. There is a solid core of established results and some topics that are not thoroughly developed. The effect of varying ultrasonic frequency is among [...] Read more.

The field of chemical and physical transformations induced by ultrasonic waves has shown steady progress during the past decades. There is a solid core of established results and some topics that are not thoroughly developed. The effect of varying ultrasonic frequency is among the most beneficial issues that require advances. In this work, the effect of sonication of Si wafers in tetrahydrofuran on the photovoltage performance was studied, with the specific goal of studying the influence of the varying frequency. The applied ultrasonic transducer design approach enables the construction of the transducer operating at about 400 kHz with a sufficient sonochemical efficiency. The measurements of the surface photovoltage (SPV) transients were performed on p-type Cz-Si(111) wafers. Sonication was done in tetrahydrofuran, methanol, and in their 3:1 mixture. When using tetrahydrofuran, the enhanced SPV signal (up to ≈80%) was observed due to increasing sonication frequency to 400 kHz. In turn, the signal was decreased down to ≈75% of the initial value when the frequency is lowered to 28 kHz. The addition of methanol suppressed this significant difference. It was implied that different decay processes with hydrogen decomposed from tetrahydrofuran could be attempted to explain the mechanism behind the observed frequency-dependent behavior. Full article

(This article belongs to the Special Issue Sonochemistry: Understanding of Ultrasonic-Based Phenomena and Innovative Applications in Chemistry: A Commemorative Issue in Honor of Dr. Jean-Louis Luche)

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20 pages, 872 KiB

Open AccessReview

Immunomodulatory Effects of Green Tea Polyphenols

by Shuzhen Wang, Zhiliang Li, Yuting Ma, Yan Liu, Chi-Chen Lin, Shiming Li, Jianfeng Zhan and Chi-Tang Ho

Molecules 2021, 26(12), 3755; https://doi.org/10.3390/molecules26123755 - 20 Jun 2021

Cited by 67 | Viewed by 8469

Abstract

Green tea and its bioactive components, especially polyphenols, possess many health-promoting and disease-preventing benefits, especially anti-inflammatory, antioxidant, anticancer, and metabolic modulation effects with multi-target modes of action. However, the effect of tea polyphenols on immune function has not been well studied. Moreover, the [...] Read more.

Green tea and its bioactive components, especially polyphenols, possess many health-promoting and disease-preventing benefits, especially anti-inflammatory, antioxidant, anticancer, and metabolic modulation effects with multi-target modes of action. However, the effect of tea polyphenols on immune function has not been well studied. Moreover, the underlying cellular and molecular mechanisms mediating immunoregulation are not well understood. This review summarizes the recent studies on the immune-potentiating effects and corresponding mechanisms of tea polyphenols, especially the main components of (–)-epigallocatechin-3-gallate (EGCG) and (–)-epicatechin-3-gallate (ECG). In addition, the benefits towards immune-related diseases, such as autoimmune diseases, cutaneous-related immune diseases, and obesity-related immune diseases, have been discussed. Full article

(This article belongs to the Special Issue 25th Anniversary of Molecules—Advances in Food Chemistry, Nutraceuticals, Functional Foods, and Dietary Bioactives: Celebrating the Lifetime Achievements of Professor Fereidoon Shahidi)

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17 pages, 2498 KiB

Open AccessArticle

The Reaction of Hydrogen Halides with Tetrahydroborate Anion and Hexahydro-closo-hexaborate Dianion

by Igor E. Golub, Oleg A. Filippov, Natalia V. Belkova, Lina M. Epstein and Elena S. Shubina

Molecules 2021, 26(12), 3754; https://doi.org/10.3390/molecules26123754 - 20 Jun 2021

Cited by 10 | Viewed by 2500

Abstract

The mechanism of the consecutive halogenation of the tetrahydroborate anion [BH₄]⁻ by hydrogen halides (HX, X = F, Cl, Br) and hexahydro-closo-hexaborate dianion [B₆H₆]²⁻ by HCl via electrophile-induced nucleophilic substitution (EINS) was established [...] Read more.

The mechanism of the consecutive halogenation of the tetrahydroborate anion [BH₄]⁻ by hydrogen halides (HX, X = F, Cl, Br) and hexahydro-closo-hexaborate dianion [B₆H₆]²⁻ by HCl via electrophile-induced nucleophilic substitution (EINS) was established by ab initio DFT calculations [M06/6-311++G(d,p) and wB97XD/6-311++G(d,p)] in acetonitrile (MeCN), taking into account non-specific solvent effects (SMD model). Successive substitution of H⁻ by X⁻ resulted in increased electron deficiency of borohydrides and changes in the character of boron atoms from nucleophilic to highly electrophilic. This, in turn, increased the tendency of the B–H bond to transfer a proton rather than a hydride ion. Thus, the regularities established suggested that it should be possible to carry out halogenation more selectively with the targeted synthesis of halogen derivatives with a low degree of substitution, by stabilization of H₂ complex, or by carrying out a nucleophilic substitution of B–H bonds activated by interaction with Lewis acids (BL₃). Full article

(This article belongs to the Special Issue Transition Metal and Main Group Hydrides: Structure, Reactivity, and Applications)

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14 pages, 9540 KiB

Open AccessArticle

Efficient One-Pot Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones via a Three-Component Biginelli Reaction

by Giovanna Bosica, Fiona Cachia, Riccardo De Nittis and Nicole Mariotti

Molecules 2021, 26(12), 3753; https://doi.org/10.3390/molecules26123753 - 20 Jun 2021

Cited by 33 | Viewed by 5083

Abstract

Multicomponent reactions are considered to be of increasing importance as time progresses due to the economic and environmental advantages such strategies entail. The three-component Biginelli reaction involves the combination of an aldehyde, a β-ketoester and urea to produce 3,4-dihydropyrimidin-2(1H)-ones, also known [...] Read more.

Multicomponent reactions are considered to be of increasing importance as time progresses due to the economic and environmental advantages such strategies entail. The three-component Biginelli reaction involves the combination of an aldehyde, a β-ketoester and urea to produce 3,4-dihydropyrimidin-2(1H)-ones, also known as DHPMs. The synthesis of these products is highly important due to their myriad of medicinal properties, amongst them acting as calcium channel blockers and antihypertensive and anti-inflammatory agents. In this study, silicotungstic acid supported on Ambelyst-15 was used as a heterogeneous catalyst for the Biginelli reaction under solventless conditions. Electron-poor aromatic aldehydes gave the best results. Sterically hindered β-ketoesters resulted in lower reaction yields. The reaction was carried out under heterogeneous catalysis to allow easy recovery of the product from the reaction mixture and recycling of the catalyst. The heterogeneity of the reaction was confirmed by carrying out a hot filtration test. Full article

(This article belongs to the Special Issue Catalysts for a Green Chemistry: A Themed Issue Honoring Professor Roger Sheldon for His Contribution in the Field of the Green Chemistry with the Introduction of the E Factor)

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32 pages, 14796 KiB

Open AccessReview

Crosslinking Strategies for the Microfluidic Production of Microgels

by Minjun Chen, Guido Bolognesi and Goran T. Vladisavljević

Molecules 2021, 26(12), 3752; https://doi.org/10.3390/molecules26123752 - 20 Jun 2021

Cited by 27 | Viewed by 7851

Abstract

This article provides a systematic review of the crosslinking strategies used to produce microgel particles in microfluidic chips. Various ionic crosslinking methods for the gelation of charged polymers are discussed, including external gelation via crosslinkers dissolved or dispersed in the oil phase; internal [...] Read more.

This article provides a systematic review of the crosslinking strategies used to produce microgel particles in microfluidic chips. Various ionic crosslinking methods for the gelation of charged polymers are discussed, including external gelation via crosslinkers dissolved or dispersed in the oil phase; internal gelation methods using crosslinkers added to the dispersed phase in their non-active forms, such as chelating agents, photo-acid generators, sparingly soluble or slowly hydrolyzing compounds, and methods involving competitive ligand exchange; rapid mixing of polymer and crosslinking streams; and merging polymer and crosslinker droplets. Covalent crosslinking methods using enzymatic oxidation of modified biopolymers, photo-polymerization of crosslinkable monomers or polymers, and thiol-ene “click” reactions are also discussed, as well as methods based on the sol−gel transitions of stimuli responsive polymers triggered by pH or temperature change. In addition to homogeneous microgel particles, the production of structurally heterogeneous particles such as composite hydrogel particles entrapping droplet interface bilayers, core−shell particles, organoids, and Janus particles are also discussed. Microfluidics offers the ability to precisely tune the chemical composition, size, shape, surface morphology, and internal structure of microgels by bringing multiple fluid streams in contact in a highly controlled fashion using versatile channel geometries and flow configurations, and allowing for controlled crosslinking. Full article

(This article belongs to the Special Issue Droplet Microfluidics: A Tool for Biology, Chemistry and Materials Engineering)

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16 pages, 3334 KiB

Open AccessReview

A Systematic Approach to Agastache mexicana Research: Biology, Agronomy, Phytochemistry, and Bioactivity

by Mariana Palma-Tenango, Rosa E. Sánchez-Fernández and Marcos Soto-Hernández

Molecules 2021, 26(12), 3751; https://doi.org/10.3390/molecules26123751 - 20 Jun 2021

Cited by 12 | Viewed by 4184

Abstract

Mexico is the center of origin of the species popularly known as toronjil or lemon balm (Agastache mexicana Linton & Epling). Two subspecies have been identified and are commonly called purple or red (Agastache mexicana Linton & Epling subspecies. mexicana) and [...] Read more.

Mexico is the center of origin of the species popularly known as toronjil or lemon balm (Agastache mexicana Linton & Epling). Two subspecies have been identified and are commonly called purple or red (Agastache mexicana Linton & Epling subspecies. mexicana) and white (Agastache mexicana subspecies xolocotziana Bye, E.L. Linares & Ramamoorthy). Plants from these subspecies differ in the size and form of inflorescence and leaves. They also possess differences in their chemical compositions, including volatile compounds. Traditional Mexican medicine employs both subspecies. A. mexicana exhibits a broad range of pharmacological properties, such as anti-inflammatory, anxiolytic, and antioxidant. A systematic vision of these plant’s properties is discussed in this review, exposing its significant potential as a source of valuable bioactive compounds. Furthermore, this review provides an understanding of the elements that make up the species’ holistic system to benefit from lemon balm sustainably. Full article

(This article belongs to the Special Issue Theme Issue Honoring Professor Robert Verpoorte’s 75th Birthday: Past, Current and Future of Natural Products Research)

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11 pages, 1628 KiB

Open AccessArticle

The Influence of 5′R and 5′S cdA and cdG on the Activity of BsmAI and SspI Restriction Enzymes

by Michał Szewczuk, Karolina Boguszewska, Julia Kaźmierczak-Barańska and Bolesław T. Karwowski

Molecules 2021, 26(12), 3750; https://doi.org/10.3390/molecules26123750 - 19 Jun 2021

Cited by 3 | Viewed by 2294

Abstract

Restriction endonucleases (REs) are intra-bacterial scissors that are considered tools in the fight against foreign genetic material. SspI and BsmAI, examined in this study, cleave dsDNA at their site of recognition or within a short distance of it. Both enzymes are representatives of [...] Read more.

Restriction endonucleases (REs) are intra-bacterial scissors that are considered tools in the fight against foreign genetic material. SspI and BsmAI, examined in this study, cleave dsDNA at their site of recognition or within a short distance of it. Both enzymes are representatives of type II REs, which have played an extremely important role in research on the genetics of organisms and molecular biology. Therefore, the study of agents affecting their activity has become highly important. Ionizing radiation may damage basic cellular mechanisms by inducing lesions in the genome, with 5′,8-cyclo-2′-deoxypurines (cdPus) as a model example. Since cdPus may become components of clustered DNA lesions (CDLs), which are unfavorable for DNA repair pathways, their impact on other cellular mechanisms is worthy of attention. This study investigated the influence of cdPus on the elements of the bacterial restriction–modification system. In this study, it was shown that cdPus present in DNA affect the activity of REs. SspI was blocked by any cdPu lesion present at the enzyme’s recognition site. When lesions were placed near the recognition sequence, the SspI was inhibited up to 46%. Moreover, (5′S)-5′,8-cyclo-2′-deoxyadenosine (ScdA) present in the oligonucleotide sequence lowered BsmAI activity more than (5′R)-5′,8-cyclo-2′-deoxyadenosine (RcdA). Interestingly, in the case of 5′,8-cyclo-2′-deoxyguanosine (cdG), both 5′S and 5′R diastereomers inhibited BsmAI activity (up to 55% more than cdA). The inhibition was weaker when cdG was present at the recognition site rather than the cleavage site. Full article

(This article belongs to the Special Issue Research and Development of DNA Repair Inhibitors)

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18 pages, 4434 KiB

Open AccessArticle

Temperature-Dependent Dynamical Evolution in Coum/SBE-β-CD Inclusion Complexes Revealed by Two-Dimensional FTIR Correlation Spectroscopy (2D-COS)

by Giuseppe Paladini, Francesco Caridi, Vincenza Crupi, Federica De Gaetano, Domenico Majolino, Silvana Tommasini, Cinzia Anna Ventura, Valentina Venuti and Rosanna Stancanelli

Molecules 2021, 26(12), 3749; https://doi.org/10.3390/molecules26123749 - 19 Jun 2021

Cited by 14 | Viewed by 2365

Abstract

A combination of Fourier transform infrared spectroscopy in attenuated total reflectance geometry (FTIR-ATR) and 2D correlation analysis (2D-COS) was applied here for the first time in order to investigate the temperature-dependent dynamical evolution occurring in a particular type of inclusion complex, based on [...] Read more.

A combination of Fourier transform infrared spectroscopy in attenuated total reflectance geometry (FTIR-ATR) and 2D correlation analysis (2D-COS) was applied here for the first time in order to investigate the temperature-dependent dynamical evolution occurring in a particular type of inclusion complex, based on sulfobutylether-β-cyclodextrin (SBE-β-CD) as hosting agent and Coumestrol (7,12-dihydorxcoumestane, Coum), a poorly-soluble active compound known for its anti-viral and anti-oxidant activity. For this purpose, synchronous and asynchronous 2D spectra were calculated in three different wavenumber regions (960–1320 cm⁻¹, 1580–1760 cm⁻¹ and 2780–3750 cm⁻¹) and over a temperature range between 250 K and 340 K. The resolution enhancement provided by the 2D-COS offers the possibility to extract the sequential order of events tracked by specific functional groups of the system, and allows, at the same time, the overcoming of some of the limits associated with conventional 1D FTIR-ATR analysis. Acquired information could be used, in principle, for the definition of an optimized procedure capable to provide high-performance T-sensitive drug carrier systems for different applications. Full article

(This article belongs to the Special Issue Hybrid Compounds Tailoring at the Nanoscale for Biomedical Applications)

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8 pages, 4960 KiB

Open AccessArticle

Two Intercalation Mechanisms of Oxazole Yellow Dimer (YOYO-1) into DNA

by Karolina Kucharska, Marta Pilz, Krzysztof Bielec, Tomasz Kalwarczyk, Patrycja Kuźma and Robert Hołyst

Molecules 2021, 26(12), 3748; https://doi.org/10.3390/molecules26123748 - 19 Jun 2021

Cited by 2 | Viewed by 4014

Abstract

The oxazole yellow dye, YOYO-1 (a symmetric homodimer), is a commonly used molecule for staining DNA. We applied the brightness analysis to study the intercalation of YOYO-1 into the DNA. We distinguished two binding modes of the dye to dsDNA: mono-intercalation and bis-intercalation. [...] Read more.

The oxazole yellow dye, YOYO-1 (a symmetric homodimer), is a commonly used molecule for staining DNA. We applied the brightness analysis to study the intercalation of YOYO-1 into the DNA. We distinguished two binding modes of the dye to dsDNA: mono-intercalation and bis-intercalation. Bis-intercalation consists of two consecutive mono-intercalation steps, characterised by two distinct equilibrium constants (with the average number of base pair per binding site equals 3.5):

K_{1} = 3.36 \pm 0.43 \times 10^{7} M^{- 1}

and

K_{2} = 1.90 \pm 0.61 \times 10^{5} M^{- 1}

, respectively. Mono-intercalation dominates at high concentrations of YOYO-1. Bis-intercalation occurs at low concentrations. Full article

(This article belongs to the Special Issue Ligand Binding to DNA and RNA)

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8 pages, 2271 KiB

Open AccessCommunication

Will the Bacteria Survive in the CeO₂ Nanozyme-H₂O₂ System?

by Weisheng Zhu, Luyao Wang, Qisi Li, Lizhi Jiao, Xiaokan Yu, Xiangfan Gao, Hao Qiu, Zhijun Zhang and Wei Bing

Molecules 2021, 26(12), 3747; https://doi.org/10.3390/molecules26123747 - 19 Jun 2021

Cited by 15 | Viewed by 3332

Abstract

As one of the nanostructures with enzyme-like activity, nanozymes have recently attracted extensive attention for their biomedical applications, especially for bacterial disinfection treatment. Nanozymes with high peroxidase activity are considered to be excellent candidates for building bacterial disinfection systems (nanozyme-H₂O₂ [...] Read more.

As one of the nanostructures with enzyme-like activity, nanozymes have recently attracted extensive attention for their biomedical applications, especially for bacterial disinfection treatment. Nanozymes with high peroxidase activity are considered to be excellent candidates for building bacterial disinfection systems (nanozyme-H₂O₂), in which the nanozyme will promote the generation of ROS to kill bacteria based on the decomposition of H₂O₂. According to this criterion, a cerium oxide nanoparticle (Nanoceria, CeO₂, a classical nanozyme with high peroxidase activity)-based nanozyme-H₂O₂ system would be very efficient for bacterial disinfection. However, CeO₂ is a nanozyme with multiple enzyme-like activities. In addition to high peroxidase activity, CeO₂ nanozymes also possess high superoxide dismutase activity and antioxidant activity, which can act as a ROS scavenger. Considering the fact that CeO₂ nanozymes have both the activity to promote ROS production and the opposite activity for ROS scavenging, it is worth exploring which activity will play the dominating role in the CeO₂-H₂O₂ system, as well as whether it will protect bacteria or produce an antibacterial effect. In this work, we focused on this discussion to unveil the role of CeO₂ in the CeO₂-H₂O₂ system, so that it can provide valuable knowledge for the design of a nanozyme-H₂O₂-based antibacterial system. Full article

(This article belongs to the Special Issue Advances in Biomimetic Materials)

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18 pages, 814 KiB

Open AccessArticle

Conventional and Organic Honeys as a Source of Water- and Ethanol-Soluble Molecules with Nutritional and Antioxidant Characteristics

by Magdalena Polak-Śliwińska and Małgorzata Tańska

Molecules 2021, 26(12), 3746; https://doi.org/10.3390/molecules26123746 - 19 Jun 2021

Cited by 4 | Viewed by 2861

Abstract

The benefits of natural honeybee products (e.g., honey, royal jelly, beeswax, propolis, beevenom and pollen) to the immune system are remarkable, and many of them are involved in the induction of antibody production, maturation of immune cells and stimulation of the immune system. [...] Read more.

The benefits of natural honeybee products (e.g., honey, royal jelly, beeswax, propolis, beevenom and pollen) to the immune system are remarkable, and many of them are involved in the induction of antibody production, maturation of immune cells and stimulation of the immune system. The type of plants in the geographical area, climatic conditions and production method have a significantly influence on the nutritional quality of honey. However, this variability can influence consumer liking by the sensory attributes of the product. The aim of this work was to compare the most popular honeys from Poland in terms of nutritional value, organoleptic properties and antioxidant activity. In the study, five varieties of honey (honeydew, forest, buckwheat, linden and dandelion) from conventional and organic production methods were tested. The nutritional characteristics of honey samples included acidity, content of water, sugars, vitamin C, HMF and phenolics (total and flavonoids), while honey color, taste, aroma and consistency were investigated in the organoleptic characteristics. The antioxidant activity was determined in water- and ethanol-soluble honey extracts using DPPH and ORAC tests. The results showed that organoleptic and nutritional characteristics of popular Polish honeys differ significantly in relation to plant source and production method. The significant effect of honey variety on the content of HMF, saccharose and phenolics, as well as acidity and antioxidant capacity were noted. The impact of variety and variety × production method interaction was significant in the case of the content of vitamin C, glucose and fructose. A visible difference of buckwheat and forest honeys from other samples was observed. The highest content of total phenolics with antioxidant activity based on the SET mechanism was found in buckwheat honeys, while forest honeys were richer in flavonoids. Full article

(This article belongs to the Special Issue Natural Product-Inspired Molecules: From Weed to Remedy)

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