Molecules

14 pages, 5147 KiB

Open AccessArticle

Tuning Photophysical Properties via Positional Isomerization of the Pyridine Ring in Donor–Acceptor-Structured Aggregation-Induced Emission Luminogens Based on Phenylmethylene Pyridineacetonitrile Derivatives

by Haiya Sun, Shuixin Chen, Aiguo Zhong, Rong Sun, Jiajie Jin, Jiahao Yang, Dongzhi Liu, Junfeng Niu and Shengli Lu

Molecules 2023, 28(7), 3282; https://doi.org/10.3390/molecules28073282 - 6 Apr 2023

Cited by 40 | Viewed by 2319

Abstract

A series of aggregation-induced emission (AIE)-featured phenylmethylene pyridineacetonitrile derivatives named o-DBCNPy ((Z)-3-(4-(di-p-tolylamino)phenyl)-2-(pyridin-2-yl)acrylonitrile), m-DBCNPy ((Z)-3-(4-(di-p-tolylamino)phenyl)-2-(pyridin-3-yl)acrylonitrile), and p-DBCNPy ((Z)-3-(4-(di-p-tolylamino)phenyl)-2-(pyridin-4-yl)acrylonitrile) have been synthesized by tuning the substitution position of the pyridine [...] Read more.

A series of aggregation-induced emission (AIE)-featured phenylmethylene pyridineacetonitrile derivatives named o-DBCNPy ((Z)-3-(4-(di-p-tolylamino)phenyl)-2-(pyridin-2-yl)acrylonitrile), m-DBCNPy ((Z)-3-(4-(di-p-tolylamino)phenyl)-2-(pyridin-3-yl)acrylonitrile), and p-DBCNPy ((Z)-3-(4-(di-p-tolylamino)phenyl)-2-(pyridin-4-yl)acrylonitrile) have been synthesized by tuning the substitution position of the pyridine ring. The linkage manner of the pyridine ring had influences on the molecular configuration and conjugation, thus leading to different photophysical properties. The absorption and fluorescence emission peak showed a bathochromic shift when the linking position of the pyridine ring changed from the meta to the ortho and para position. Meanwhile, o-DBCNPy exhibited the highest fluorescence quantum yield of 0.81 and the longest fluorescence lifetime of 7.96 ns as a neat film among all three isomers. Moreover, non-doped organic light-emitting diodes (OLEDs) were assembled in which the molecules acted as the light-emitting layer. Due to the relatively prominent emission properties, the electroluminescence (EL) performance of the o-DBCNPy-based OLED was superior to those of the devices based on the other two isomers with an external quantum efficiency (EQE) of 4.31%. The results indicate that delicate molecular modulation of AIE molecules could endow them with improved photophysical properties, making them potential candidates for organic photoelectronic devices. Full article

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25 pages, 1607 KiB

Open AccessReview

Maltooligosaccharides: Properties, Production and Applications

by Mária Bláhová, Vladimír Štefuca, Helena Hronská and Michal Rosenberg

Molecules 2023, 28(7), 3281; https://doi.org/10.3390/molecules28073281 - 6 Apr 2023

Cited by 6 | Viewed by 4442

Abstract

Maltooligosaccharides (MOS) are homooligosaccharides that consist of 3–10 glucose molecules linked by α-1,4 glycosidic bonds. As they have physiological functions, they are commonly used as ingredients in nutritional products and functional foods. Many researchers have investigated the potential applications of MOS and their [...] Read more.

Maltooligosaccharides (MOS) are homooligosaccharides that consist of 3–10 glucose molecules linked by α-1,4 glycosidic bonds. As they have physiological functions, they are commonly used as ingredients in nutritional products and functional foods. Many researchers have investigated the potential applications of MOS and their derivatives in the pharmaceutical industry. In this review, we summarized the properties and methods of fabricating MOS and their derivatives, including sulfated and non-sulfated alkylMOS. For preparing MOS, different enzymatic strategies have been proposed by various researchers, using α-amylases, maltooligosaccharide-forming amylases, or glycosyltransferases as effective biocatalysts. Many researchers have focused on using immobilized biocatalysts and downstream processes for MOS production. This review also provides an overview of the current challenges and future trends of MOS production. Full article

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11 pages, 3649 KiB

Open AccessArticle

CAl₄X₄ (X = Te, Po): Double Aromatic Molecular Stars Containing Planar Tetracoordinate Carbon Atoms

by Li-Xia Bai and Jin-Chang Guo

Molecules 2023, 28(7), 3280; https://doi.org/10.3390/molecules28073280 - 6 Apr 2023

Cited by 3 | Viewed by 1793

Abstract

Planar tetracoordinate carbon (ptC) species are scarce and exotic. Introducing four peripheral Te/Po auxiliary atoms is an effective strategy to flatten the tetrahedral structure of CAl₄ (T_d, ¹A₁). Neutral CAl₄X₄ (X = Te, [...] Read more.

Planar tetracoordinate carbon (ptC) species are scarce and exotic. Introducing four peripheral Te/Po auxiliary atoms is an effective strategy to flatten the tetrahedral structure of CAl₄ (T_d, ¹A₁). Neutral CAl₄X₄ (X = Te, Po) clusters possess quadrangular star structures containing perfect ptC centers. Unbiased density functional theory (DFT) searches and high-level CCSD(T) calculations suggest that these ptC species are the global minima on the potential energy surfaces. Bonding analyses indicate that 40 valence-electron (VE) is ideal for the ptC CAl₄X₄ (X = Te, Po): one delocalized π and three σ bonds for the CAl₄ core; four lone pairs (LPs) of four X atoms, eight localized Al–X σ bonds, and four delocalized Al–X–Al π bonds for the periphery. Thus, the ptC CAl₄X₄ (X = Te, Po) clusters possess the stable eight electron structures and 2π + 6σ double aromaticity. Born–Oppenheimer molecular dynamics (BOMD) simulations indicate that neutral ptC CAl₄X₄ (X = Te, Po) clusters are robust. Full article

(This article belongs to the Special Issue Aromatic Inorganic and Metallic Compounds)

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12 pages, 2367 KiB

Open AccessArticle

New Strategy for the Design of Anti-Corrosion Coatings in Bipolar Plates Based on Hybrid Organic–Inorganic Layers

by Xiaoxuan Li, Wenjie Sun, Yuhui Zheng, Chenggang Long and Qianming Wang

Molecules 2023, 28(7), 3279; https://doi.org/10.3390/molecules28073279 - 6 Apr 2023

Cited by 2 | Viewed by 1921

Abstract

As a star material in conducting polymers, a polypyrrole coating was assembled onto the surface of 316 stainless steel by an electrochemical method. In the next step, the composite layer consisting of carbon nitride nanosheets (CNNS) and polymethyl methacrylate (PMMA) was sprayed. The [...] Read more.

As a star material in conducting polymers, a polypyrrole coating was assembled onto the surface of 316 stainless steel by an electrochemical method. In the next step, the composite layer consisting of carbon nitride nanosheets (CNNS) and polymethyl methacrylate (PMMA) was sprayed. The corrosion manner of composite coatings in a simulated proton-exchange membrane fuel cell (PEMFC) environment was evaluated. The results show that the final coating generated at a voltage of 1.0 has demonstrated the optimized corrosion resistance. The polypyrrole layer improves the corrosion resistance of the stainless steel substrate, and the CNNS/PMMA coating further strengthens the physical barrier effect of the coating in corrosive solutions. Full article

(This article belongs to the Section Inorganic Chemistry)

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39 pages, 17908 KiB

Open AccessReview

A Comprehensive Review on Pharmacologically Active Phyto-Constituents from Hedychium species

by Alok Pratap Singh, Havagiray Chitme, Rajeev Kumar Sharma, JB Kandpal, Ashok Behera, Basel A. Abdel-Wahab, Mohammed Abdelmalek Orabi, Masood Medleri Khateeb, Mohammed Shafiuddin Habeeb and Marwa B. Bakir

Molecules 2023, 28(7), 3278; https://doi.org/10.3390/molecules28073278 - 6 Apr 2023

Cited by 4 | Viewed by 3739

Abstract

In this review, we describe and discuss the phytoconstituents present in Hedychium species and emphasize their potential as drug candidates. Though they are widely validated in vitro and in vivo models, to date, no efforts have been made to compile in a single [...] Read more.

In this review, we describe and discuss the phytoconstituents present in Hedychium species and emphasize their potential as drug candidates. Though they are widely validated in vitro and in vivo models, to date, no efforts have been made to compile in a single review all the pharmacologically active phytoconstituents from Hedychium species, and their pharmacological and toxicity profile. In this study, we present a reinvestigation of the chemical constituents present in Hedychium species obtained from the essential oil and solvent extraction of the flowers, leaves and rhizomes under consideration. Key databases such as PubMed, Science Direct, Scopus, and Google Scholar amongst others were probed for a systematic search using keywords to retrieve relevant publications on this plant. An exhaustive electronic survey of the related literature on Hedychium species resulted in around 200 articles. Articles published between the years 1975–2021 were included. The studies conducted on either crude extracts, solvent fractions or isolated pure compounds from Hedychium species reported with a varied range of biological effects such as anti-inflammatory, analgesic, antidiabetic, potentially anti-asthmatic, and cytotoxic, among other related activities of the chemical constituents present in its essential oil and solvent extract deployed in this review. Traditional and herbal medication around the world that uses different parts of Hedychium species were considered for anti-inflammatory, skincare, analgesic, anti-asthmatic, anti-diabetic, antidotal uses, among others. These uses support the idea that chemical constituents obtained from solvent extraction may also exert the same action individually or in a synergistic manner. The review concluded that there is scope for computation and biological study to find out possible new targets for strengthening the potency and selectivity of the relevant compounds, and to find a commercial method for extraction of active pharmaceutical ingredients. Full article

(This article belongs to the Special Issue Advances on Natural Products: Isolation, Identification and Biological Activity)

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14 pages, 3507 KiB

Open AccessArticle

In situ Electrochemical Evaluation of the Interaction of dsDNA with the Proteasome Inhibitor Anticancer Drug Bortezomib

by Mihaela-Cristina Bunea, Teodor Adrian Enache and Victor Constantin Diculescu

Molecules 2023, 28(7), 3277; https://doi.org/10.3390/molecules28073277 - 6 Apr 2023

Cited by 1 | Viewed by 1499

Abstract

Bortezomib is an inhibitor of proteasomes and an anti-cancer drug. Although bortezomib is considered a safe drug, as confirmed by cytotoxicity assays, recent reports highlighted the possibility of interaction between bortezomib and cellular components, with detrimental long-term effects. The evaluation of the interaction [...] Read more.

Bortezomib is an inhibitor of proteasomes and an anti-cancer drug. Although bortezomib is considered a safe drug, as confirmed by cytotoxicity assays, recent reports highlighted the possibility of interaction between bortezomib and cellular components, with detrimental long-term effects. The evaluation of the interaction between bortezomib and dsDNA was investigated in bulk solution and using a dsDNA electrochemical biosensor. The binding of bortezomib to dsDNA involved its electroactive centers and led to small morphological modifications in the dsDNA double helix, which were electrochemically identified through changes in the guanine and adenine residue oxidation peaks and confirmed by electrophoretic and spectrophotometric measurements. The redox product of bortezomib amino group oxidation was electrochemically generated in situ on the surface of the dsDNA electrochemical biosensor. The redox product of bortezomib was shown to interact primarily with guanine residues, preventing their oxidation and leading to the formation of bortezomib–guanine adducts, which was confirmed by control experiments with polyhomonucleotides electrochemical biosensors and mass spectrometry. An interaction mechanism between dsDNA and bortezomib is proposed, and the formation of the bortezomib redox product–guanine adduct explained. Full article

(This article belongs to the Special Issue Theme Issue in Honor of Professor Ana Maria Oliveira Brett: Bioelectrochemical Sensing and DNA Electrochemical Biosensors)

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12 pages, 3964 KiB

Open AccessArticle

Chemical Bonding and Dynamic Structural Fluxionality of a Boron-Based Na₅B₇ Sandwich Cluster

by Peng-Fei Han, Ying-Jin Wang, Lin-Yan Feng, Shu-Juan Gao, Qiang Sun and Hua-Jin Zhai

Molecules 2023, 28(7), 3276; https://doi.org/10.3390/molecules28073276 - 6 Apr 2023

Viewed by 1826

Abstract

Doping alkali metals into boron clusters can effectively compensate for the intrinsic electron deficiency of boron and lead to interesting boron-based binary clusters, owing to the small electronegativity of the former elements. We report on the computational design of a three-layered sandwich cluster, [...] Read more.

Doping alkali metals into boron clusters can effectively compensate for the intrinsic electron deficiency of boron and lead to interesting boron-based binary clusters, owing to the small electronegativity of the former elements. We report on the computational design of a three-layered sandwich cluster, Na₅B₇, on the basis of global-minimum (GM) searches and electronic structure calculations. It is shown that the Na₅B₇ cluster can be described as a charge-transfer complex: [Na₄]²⁺[B₇]³⁻[Na]⁺. In this sandwich cluster, the [B₇]³⁻ core assumes a molecular wheel in shape and features in-plane hexagonal coordination. The magic 6π/6σ double aromaticity underlies the stability of the [B₇]³⁻ molecular wheel, following the (4n + 2) Hückel rule. The tetrahedral Na₄ ligand in the sandwich has a [Na₄]²⁺ charge-state, which is the simplest example of three-dimensional aromaticity, spherical aromaticity, or superatom. Its 2σ electron counting renders σ aromaticity for the ligand. Overall, the sandwich cluster has three-fold 6π/6σ/2σ aromaticity. Molecular dynamics simulation shows that the sandwich cluster is dynamically fluxional even at room temperature, with a negligible energy barrier for intramolecular twisting between the B₇ wheel and the Na₄ ligand. The Na₅B₇ cluster offers a new example for dynamic structural fluxionality in molecular systems. Full article

(This article belongs to the Special Issue Aromatic Inorganic and Metallic Compounds)

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13 pages, 561 KiB

Open AccessArticle

Asteraceae Seeds as Alternative Ingredients in a Fibre-Rich Diet: Protein Quality and Metabolic Effects in Rats

by Jarosław Koza and Adam Jurgoński

Molecules 2023, 28(7), 3275; https://doi.org/10.3390/molecules28073275 - 6 Apr 2023

Cited by 1 | Viewed by 1571

Abstract

We verified whether milk thistle seeds and pot marigold seeds provided valuable components for a fibre-rich diet and how their addition affected body composition, nitrogen balance and lipid metabolism in rats. Growing rats were fed a control diet (5% fibre) or three fibre-rich [...] Read more.

We verified whether milk thistle seeds and pot marigold seeds provided valuable components for a fibre-rich diet and how their addition affected body composition, nitrogen balance and lipid metabolism in rats. Growing rats were fed a control diet (5% fibre) or three fibre-rich diets (24% fibre), which contained cellulose as the sole source of fibre (24%; positive control), milk thistle seeds (32%) or pot marigold seeds (39%). All diets were balanced in macronutrients, including total protein content (9%), which was half of the amount recommended for rats to maximise protein absorption and utilisation, and the ratio of plant protein to animal protein (approx. 1:1). After 4 weeks, dietary pot marigold seeds reduced body weight gain, which translated into lower gains of body fat and lean mass in rats (all at p ≤ 0.05). Protein digestibility differed among individual fibre-rich diets (p ≤ 0.05), with the lowest result having been recorded for dietary pot marigold seeds (73%), followed by dietary milk thistle seeds (78%), and the highest result having been recorded for dietary soybean protein isolate (control protein source, 89%). Nitrogen retention was higher with dietary soybean protein isolate (53%) and dietary milk thistle seeds (47%) than with dietary pot marigold seeds (38%) (p ≤ 0.05). In the caecal digesta, the concentrations of the major short-chain fatty acids were almost or >2-fold higher after dietary milk thistle seeds and pot marigold seeds than after the positive control diet (all at p ≤ 0.05). Dietary pot marigold seeds enlarged the liver and increased the plasma activities of liver enzymes but reduced hepatic lipid contents (all at p ≤ 0.05). Certain Asteraceae seeds provide components of varied nutritional quality, with milk thistle seeds being a relatively good source of protein and both types of seeds being a source of fermentable fibre. Pot marigold seeds have potential anti-obesogenic effects, but with the risk of damaging internal organs. Full article

(This article belongs to the Special Issue Biomedical Aspects of Nutrition and Functional Food)

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11 pages, 3238 KiB

Open AccessArticle

Preparation of Mesoporous Si Nanoparticles by Magnesiothermic Reduction for the Enhanced Reactivity

by Xinwen Ma, Weiduo Fei, Xiandie Zhang, Jie Ji and Xiang Zhou

Molecules 2023, 28(7), 3274; https://doi.org/10.3390/molecules28073274 - 6 Apr 2023

Cited by 2 | Viewed by 2035

Abstract

In this study, mesoporous silicon nanoparticles (M-Si) were successfully prepared by a magnesiothermic reduction of mesoporous silica nanoparticles, which were synthesized by a templated sol-gel method and used as the precursors. M-Si exhibited a uniform size distribution with an average diameter of about [...] Read more.

In this study, mesoporous silicon nanoparticles (M-Si) were successfully prepared by a magnesiothermic reduction of mesoporous silica nanoparticles, which were synthesized by a templated sol-gel method and used as the precursors. M-Si exhibited a uniform size distribution with an average diameter of about 160 nm. The measured BET surface area was 93.0 m² g⁻¹, and the average pore size calculated by the BJH method was 16 nm. The large internal surface area provides rich reaction sites, resulting in unique interfacial properties and reduced mass diffusion limitations. The mechanism of the magnesiothermic reduction process was discussed. The reactivity of prepared M-Si was compared with that of commercially available non-porous Si nanopowder (with the average diameter of about 30 nm) by performing simultaneous thermogravimetry and differential scanning calorimetry in the air. The results showed that the reaction onset temperature indicated by weight gain was advanced from 772 °C to 468 °C, indicating the promising potential of M-Si as fuel for metastable intermolecular composites. Full article

(This article belongs to the Special Issue Research and Application of Nanoenergetic Materials)

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15 pages, 2790 KiB

Open AccessArticle

Structural (XRD) Characterization and an Analysis of H-Bonding Motifs in Some Tetrahydroxidohexaoxidopentaborate(1-) Salts of N-Substituted Guanidinium Cations

by Michael A. Beckett, Simon J. Coles, Peter N. Horton and Thomas A. Rixon

Molecules 2023, 28(7), 3273; https://doi.org/10.3390/molecules28073273 - 6 Apr 2023

Cited by 2 | Viewed by 1696

Abstract

The synthesis and characterization of six new substituted guanidium tetrahydroxidohexaoxidopentaborate(1-) salts are reported: [C(NH₂)₂(NHMe)][B₅O₆(OH)₄]·H₂O (1), [C(NH₂)₂(NH{NH₂})][B₅O₆(OH)₄] ( [...] Read more.

The synthesis and characterization of six new substituted guanidium tetrahydroxidohexaoxidopentaborate(1-) salts are reported: [C(NH₂)₂(NHMe)][B₅O₆(OH)₄]·H₂O (1), [C(NH₂)₂(NH{NH₂})][B₅O₆(OH)₄] (2), [C(NH₂)₂(NMe₂)][B₅O₆(OH)₄] (3), [C(NH₂)(NMe₂)₂][B₅O₆(OH)₄] (4), [C(NHMe)(NMe₂)₂][B₅O₆(OH)₄]·B(OH)₃ (5), and [TBDH][B₅O₆(OH)₄] (6) (TBD = 1,5,7-triazabicyclo [4.4.0]dec-5-ene). Compounds 1–6 were prepared as crystalline salts from basic aqueous solution via self-assembly processes from B(OH)₃ and the appropriate substituted cation. Compounds 1–6 were characterized by spectroscopic (NMR and IR) and by single-crystal XRD studies. A thermal (TGA) analysis on compounds 1–3 and 6 demonstrated that they thermally decomposed via a multistage process to B₂O₃ at >650 °C. The low temperature stage (<250 °C) was endothermic and corresponded to a loss of H₂O. Reactant stoichiometry, solid-state packing, and H-bonding interactions are all important in assembling these structures. An analysis of H-bonding motifs in known unsubstituted guanidinium salts [C(NH₂)₃]₂[B₄O₅(OH)₄]·2H₂O, [C(NH₂)₃][B₅O₆(OH)₄]·H₂O, and [C(NH₂)₃]₃[B₉O₁₂(OH)₆] and in compounds 1–6 revealed that two important H-bonding R₂²(8) motifs competed to stabilize the observed structures. The guanidinium cation formed charge-assisted pincer cation–anion H-bonded rings as a major motif in [C(NH₂)₃]₂[B₄O₅(OH)₄]·2H₂O and [C(NH₂)₃]₃[B₉O₁₂(OH)₆], whereas the anion–anion ring motif was dominant in [C(NH₂)₃][B₅O₆(OH)₄]·H₂O and in compounds 1–6. This behaviour was consistent with the stoichiometry of the salt and packing effects also strongly influencing their solid-state structures. Full article

(This article belongs to the Special Issue New Developments in Boron Chemistry: From Oxidoborates to Hydrido(hetero)borane Derivatives – in Celebration of Professor John D. Kennedy’s 80th Birthday)

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11 pages, 1870 KiB

Open AccessArticle

Evaluating the Application Potential of a Recombinant Ganoderma Protein as Bioactive Ingredients in Cosmetics

by Zhi-Jian Guo, Yan Liu, Jia-Yi Yang, Meng-Yuan Jin, Pei-Wen Mao and Xuan-Wei Zhou

Molecules 2023, 28(7), 3272; https://doi.org/10.3390/molecules28073272 - 6 Apr 2023

Cited by 3 | Viewed by 2203

Abstract

The aim of this study was to evaluate the application potential of a recombinant fungal immunomodulatory protein from Ganoderma lucidum (rFIP-glu). First, a recombinant plasmid pPIC9K::FIP-glu-His was transferred into Pichia pastoris for the production of protein. The protein was then to assess its [...] Read more.

The aim of this study was to evaluate the application potential of a recombinant fungal immunomodulatory protein from Ganoderma lucidum (rFIP-glu). First, a recombinant plasmid pPIC9K::FIP-glu-His was transferred into Pichia pastoris for the production of protein. The protein was then to assess its free radical scavenging abilities and the effect on the viability of both human immortalized keratinocytes (HaCaT cells) and mouse B16-F10 melanoma cells (B16 cells) in vitro, followed by the effect on the melanin synthesis of B16 cells. The results of SDS-PAGE and western blot showed that rFIP-glu was successfully expressed. Furtherly, a bioactivity assay in vitro indicated that the scavenging rate of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals reached 84.5% at 6.0 mg/mL (p ≤ 0.0001) of rFIP-glu, showing strong antioxidant activity. Subsequently, a safety evaluation demonstrated that rFIP-glu promoted the proliferation of HaCaT cells, with the cell viability reaching 124.3% at 48 μg/mL (p ≤ 0.01), regarding the cell viability of B16 cells after exposure to rFIP-glu (48 μg/mL) significantly inhibited, to 80.7% (p ≤ 0.01). Besides, rFIP-glu inhibited the melanin synthesis of B16 cells in a dose-dependent manner from 100–1000 μg/mL, and rFIP-glu at 500 μg/mL (p ≤ 0.01) exhibited the highest intracellular melanin amount reduction of 16.8%. Furthermore, a mechanism analysis showed that rFIP-glu inhibited tyrosinase (TYR) activity by up-regulating the expression of the microphthalmia-associated transcription factor (MITF) and down-regulating the gene expression of TYR and tyrosinase-related protein-1 (TYRP-1), thus inhibiting melanin synthesis. The data implied that rFIP-glu had significant antioxidant activity and whitening potency. It should be used as raw materials for cosmeceutical applications. Full article

(This article belongs to the Special Issue Natural Products and Biomolecules for Cosmetics Applications)

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26 pages, 2474 KiB

Open AccessReview

The Polypharmacological Effects of Cannabidiol

by Jorge Castillo-Arellano, Ana Canseco-Alba, Stephen J. Cutler and Francisco León

Molecules 2023, 28(7), 3271; https://doi.org/10.3390/molecules28073271 - 6 Apr 2023

Cited by 39 | Viewed by 9736

Abstract

Cannabidiol (CBD) is a major phytocannabinoid present in Cannabis sativa (Linneo, 1753). This naturally occurring secondary metabolite does not induce intoxication or exhibit the characteristic profile of drugs of abuse from cannabis like Δ⁹-tetrahydrocannabinol (∆⁹-THC) does. In contrast to [...] Read more.

Cannabidiol (CBD) is a major phytocannabinoid present in Cannabis sativa (Linneo, 1753). This naturally occurring secondary metabolite does not induce intoxication or exhibit the characteristic profile of drugs of abuse from cannabis like Δ⁹-tetrahydrocannabinol (∆⁹-THC) does. In contrast to ∆⁹-THC, our knowledge of the neuro-molecular mechanisms of CBD is limited, and its pharmacology, which appears to be complex, has not yet been fully elucidated. The study of the pharmacological effects of CBD has grown exponentially in recent years, making it necessary to generate frequently updated reports on this important metabolite. In this article, a rationalized integration of the mechanisms of action of CBD on molecular targets and pharmacological implications in animal models and human diseases, such as epilepsy, pain, neuropsychiatric disorders, Alzheimer’s disease, and inflammatory diseases, are presented. We identify around 56 different molecular targets for CBD, including enzymes and ion channels/metabotropic receptors involved in neurologic conditions. Herein, we compiled the knowledge found in the scientific literature on the multiple mechanisms of actions of CBD. The in vitro and in vivo findings are essential for fully understanding the polypharmacological nature of this natural product. Full article

(This article belongs to the Special Issue Improvements and Opportunities on Natural Products for Novel Drug Discovery)

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15 pages, 1289 KiB

Open AccessArticle

Evaluation of the Antioxidant Activities and Phenolic Profile of Shennongjia Apis cerana Honey through a Comparison with Apis mellifera Honey in China

by Jingwen Guo, Qiong Ding, Zhiwei Zhang, Ying Zhang, Jianshe He, Zong Yang, Ping Zhou and Xiaoyan Gong

Molecules 2023, 28(7), 3270; https://doi.org/10.3390/molecules28073270 - 6 Apr 2023

Cited by 1 | Viewed by 1741

Abstract

This study evaluates the phenolic profile as well as the antioxidant properties of Shennongjia Apis cerana honey through a comparison with Apis mellifera honey in China. The total phenolic content (TPC) ranges from 263 ± 2 to 681 ± 36 mg gallic acid/kg. [...] Read more.

This study evaluates the phenolic profile as well as the antioxidant properties of Shennongjia Apis cerana honey through a comparison with Apis mellifera honey in China. The total phenolic content (TPC) ranges from 263 ± 2 to 681 ± 36 mg gallic acid/kg. The total flavonoids content (TFC) ranges from 35.9 ± 0.4 to 102.2 ± 0.8 mg epicatechin/kg. The correlations between TPC or TFC and the antioxidant results (FRAP, DPPH, and ABTS) were found to be statistically significant (p < 0.01). Furthermore, the phenolic compounds are quantified and qualified by high performance liquid chromatography-high resolution mass spectrometry (HPLC-HRMS), and a total of 83 phenolic compounds were tentatively identified in this study. A metabolomics analysis based on the 83 polyphenols was carried out and subjected to principal component analysis and orthogonal partial least squares-discriminant analysis. The results showed that it was possible to distinguish Apis cerana honey from Apis mellifera honey based on the phenolic profile. Full article

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15 pages, 1205 KiB

Open AccessArticle

An Overview on Fecal Profiles of Amino Acids and Related Amino-Derived Compounds in Children with Autism Spectrum Disorder in Tunisia

by Mariem Chamtouri, Abderrahmen Merghni, Nuria Salazar, Begoña Redruello, Naoufel Gaddour, Maha Mastouri, Silvia Arboleya and Clara G. de los Reyes-Gavilán

Molecules 2023, 28(7), 3269; https://doi.org/10.3390/molecules28073269 - 6 Apr 2023

Cited by 7 | Viewed by 2250

Abstract

Autism spectrum disorder (ASD) is a neurodevelopmental pathology characterized by the impairment of social interaction, difficulties in communication, and repetitive behaviors. Alterations in the metabolism of amino acids have been reported. We performed a chromatographic analysis of fecal amino acids, ammonium, biogenic amines, [...] Read more.

Autism spectrum disorder (ASD) is a neurodevelopmental pathology characterized by the impairment of social interaction, difficulties in communication, and repetitive behaviors. Alterations in the metabolism of amino acids have been reported. We performed a chromatographic analysis of fecal amino acids, ammonium, biogenic amines, and gamma aminobutyric acid (GABA) in Tunisian autistic children from 4 to 10 years, and results were compared with their siblings (SIB) and children from the general population (GP). ASD presented significantly higher levels of fecal amino acids than SIB and GP; differences being more pronounced in younger (4–7 years) than in older (8–10 years) individuals whereas no changes were found for the remaining compounds. Lower levels of histidine were the only difference related with severe symptoms of autism (CARS scale). A linear discriminant analysis (LDA) based on fecal amino acid profiles clearly separated ASD, SIB, and GP at 4 to 7 years but not at more advanced age (8–10 years), evidencing more pronounced alterations in younger children. The relationship of fecal amino acids with autism needs deeper research integrating blood analytical parameters, brain metabolism, and intestinal microbiota. Fecal amino acids could be targeted for designing personalized diets to prevent or minimize cognitive impairments associated with ASD. Full article

(This article belongs to the Section Chemical Biology)

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14 pages, 2421 KiB

Open AccessArticle

Optimization of Medium Constituents for the Production of Citric Acid from Waste Glycerol Using the Central Composite Rotatable Design of Experiments

by Ewelina Ewa Książek, Małgorzata Janczar-Smuga, Jerzy Jan Pietkiewicz and Ewa Walaszczyk

Molecules 2023, 28(7), 3268; https://doi.org/10.3390/molecules28073268 - 6 Apr 2023

Cited by 2 | Viewed by 2003

Abstract

Citric acid is currently produced by submerged fermentation of sucrose with the aid of Aspergillus niger mold. Its strains are characterized by a high yield of citric acid biosynthesis and no toxic by-products. Currently, new substrates are sought for production of citric acid [...] Read more.

Citric acid is currently produced by submerged fermentation of sucrose with the aid of Aspergillus niger mold. Its strains are characterized by a high yield of citric acid biosynthesis and no toxic by-products. Currently, new substrates are sought for production of citric acid by submerged fermentation. Waste materials such as glycerol or pomace could be used as carbon sources in the biosynthesis of citric acid. Due to the complexity of the metabolic state in fungus, there is an obvious need to optimize the important medium constituents to enhance the accumulation of desired product. Potential optimization approach is a statistical method, such as the central composite rotatable design (CCRD). The aim of this study was to increase the yield of citric acid biosynthesis by Aspergillus niger PD-66 in media with waste glycerol as the carbon source. A mathematical method was used to optimize the culture medium composition for the biosynthesis of citric acid. In order to maximize the efficiency of the biosynthesis of citric acid the central composite, rotatable design was used. Waste glycerol and ammonium nitrate were identified as significant variables which highly influenced the final concentration of citric acid (Y₁), volumetric rate of citric acid biosynthesis (Y₂), and yield of citric acid biosynthesis (Y₃). These variables were subsequently optimized using a central composite rotatable design. Optimal values of input variables were determined using the method of the utility function. The highest utility value of 0.88 was obtained by the following optimal set of conditions: waste glycerol—114.14 g∙L⁻¹and NH₄NO₃—2.85 g∙L⁻¹. Full article

(This article belongs to the Special Issue The Impact of Advances in Fermentation Processes on the Chemical Composition of the Final Product)

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15 pages, 2526 KiB

Open AccessArticle

Carotenoids Composition of Green Algae Caulerpa racemosa and Their Antidiabetic, Anti-Obesity, Antioxidant, and Anti-Inflammatory Properties

by Rudy Kurniawan, Fahrul Nurkolis, Nurpudji Astuti Taslim, Dionysius Subali, Reggie Surya, William Ben Gunawan, Darmawan Alisaputra, Nelly Mayulu, Netty Salindeho and Bonglee Kim

Molecules 2023, 28(7), 3267; https://doi.org/10.3390/molecules28073267 - 6 Apr 2023

Cited by 40 | Viewed by 4716

Abstract

Green alga Caulerpa racemosa is an underexploited species of macroalgae, even though it is characterized by a green color that indicates an abundance of bioactive pigments, such as chlorophyll and possibly xanthophyll. Unlike chlorophyll, which has been well explored, the composition of the [...] Read more.

Green alga Caulerpa racemosa is an underexploited species of macroalgae, even though it is characterized by a green color that indicates an abundance of bioactive pigments, such as chlorophyll and possibly xanthophyll. Unlike chlorophyll, which has been well explored, the composition of the carotenoids of C. racemosa and its biological activities have not been reported. Therefore, this study aims to look at the carotenoid profile and composition of C. racemose and determine their biological activities, which include antidiabetic, anti-obesity, anti-oxidative, anti-inflammatory, and cytotoxicity in vitro. The detected carotenoids were all xanthophylls, which included fucoxanthin, lutein, astaxanthin, canthaxanthin, zeaxanthin, β-carotene, and β-cryptoxanthin based on orbitrap-mass spectrometry (MS) and a rapid ultra-high performance liquid chromatography (UHPLC) diode array detector. Of the seven carotenoids observed, it should be highlighted that β-carotene and canthaxanthin were the two most dominant carotenoids present in C. racemosa. Interestingly, the carotenoid extract of C. racemosa has good biological activity in inhibiting α-glucosidase, α-amylase, DPPH and ABTS, and the TNF-α and mTOR, as well as upregulating the AMPK, which makes it a drug candidate or functional antidiabetic food, a very promising anti-obesity and anti-inflammatory. More interestingly, the cytotoxicity value of the carotenoid extract of C. racemosa shows a level of safety in normal cells, which makes it a potential for the further development of nutraceuticals and pharmaceuticals. Full article

(This article belongs to the Special Issue Discovery of Bioactive Ingredients from Natural Products, 4th Edition)

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22 pages, 4106 KiB

Open AccessArticle

Properties of Naked Silver Clusters with Up to 100 Atoms as Found with Embedded-Atom and Density-Functional Calculations

by Shivangi Garg, Navjot Kaur, Neetu Goel, Mohammad Molayem, Valeri G. Grigoryan and Michael Springborg

Molecules 2023, 28(7), 3266; https://doi.org/10.3390/molecules28073266 - 6 Apr 2023

Cited by 4 | Viewed by 2275

Abstract

The structural and energetic properties of small silver clusters Ag

_{n}

with n = 2–100 atoms are reported. For n = 2–100 the embedded atom model for the calculation of the total energy of a given structure in combination with the basin-hopping search [...] Read more.

The structural and energetic properties of small silver clusters Ag

_{n}

with n = 2–100 atoms are reported. For n = 2–100 the embedded atom model for the calculation of the total energy of a given structure in combination with the basin-hopping search strategy for an unbiased structure optimization has been used to identify the energies and structures of the three energetically lowest-lying isomers. These optimized structures for n = 2–11 were subsequently studied further through density-functional-theory calculations. These calculations provide additional information on the electronic properties of the clusters that is lacking in the embedded-atom calculations. Thereby, also quantities related to the catalytic performance of the clusters are studied. The calculated properties in comparison to other available theoretical and experimental data show a good agreement. Previously unidentified magic (i.e., particularly stable) clusters have been found for

n > 80

. In order to obtain a more detailed understanding of the structural properties of the clusters, various descriptors are used. Thereby, the silver clusters are compared to other noble metals and show some similarities to both copper and nickel systems, and also growth patterns have been identified. All vibrational frequencies of all the clusters have been calculated for the first time, and here we focus on the highest and lowest frequencies. Structural effects on the calculated frequencies were considered. Full article

(This article belongs to the Special Issue Computational Study of Non-metal and Metal Clusters)

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13 pages, 3110 KiB

Open AccessArticle

Synthesis and Behavior of DNA Oligomers Containing the Ambiguous Z-Nucleobase 5-Aminoimidazole-4-carboxamide

by Yuhei Nogi, Noriko Saito-Tarashima, Sangita Karanjit and Noriaki Minakawa

Molecules 2023, 28(7), 3265; https://doi.org/10.3390/molecules28073265 - 6 Apr 2023

Viewed by 1921

Abstract

5-Amino-1-β-D-ribofuranosylimidazole-4-carboxamide 5′-monophosphate (ZMP) is a central intermediate in de novo purine nucleotide biosynthesis. Its nucleobase moiety, 5-aminoimidazole-4-carboxamide (Z-base), is considered an ambiguous base that can pair with any canonical base owing to the rotatable nature of its 5-carboxamide group. This idea of ambiguous [...] Read more.

5-Amino-1-β-D-ribofuranosylimidazole-4-carboxamide 5′-monophosphate (ZMP) is a central intermediate in de novo purine nucleotide biosynthesis. Its nucleobase moiety, 5-aminoimidazole-4-carboxamide (Z-base), is considered an ambiguous base that can pair with any canonical base owing to the rotatable nature of its 5-carboxamide group. This idea of ambiguous base pairing due to free rotation of the carboxamide has been applied to designing mutagenic antiviral nucleosides, such as ribavirin and T-705. However, the ambiguous base-pairing ability of Z-base has not been elucidated, because the synthesis of Z-base-containing oligomers is problematic. Herein, we propose a practical method for the synthesis of Z-base-containing DNA oligomers based on the ring-opening reaction of an N¹-dinitrophenylhypoxanthine (Hxa^DNP) base. Thermal denaturation studies of the resulting oligomers revealed that the Z-base behaves physiologically as an A-like nucleobase, preferentially forming pairs with T. We tested the behavior of Z-base-containing DNA oligomers in enzyme-catalyzed reactions: in single nucleotide insertion, Klenow fragment DNA polymerase recognized Z-base as an A-like analog and incorporated dTTP as a complementary nucleotide to Z-base in the DNA template; in PCR amplification, Taq DNA polymerase similarly incorporated dTTP as a complementary nucleotide to Z-base. Our findings will contribute to the development of new mutagenic antiviral nucleoside analogs. Full article

(This article belongs to the Special Issue Organic Synthesis and Functional Evaluation of Nucleic Acids)

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19 pages, 1671 KiB

Open AccessArticle

Do Ganoderma Species Represent Novel Sources of Phenolic Based Antimicrobial Agents?

by Milena Rašeta, Jovana Mišković, Eleonora Čapelja, Ewa Zapora, Aleksandra Petrović Fabijan, Petar Knežević and Maja Karaman

Molecules 2023, 28(7), 3264; https://doi.org/10.3390/molecules28073264 - 6 Apr 2023

Cited by 6 | Viewed by 2210

Abstract

Ganoderma species have been recognized as potential antimicrobial (AM) agents and have been used in traditional Chinese medicine (TCM) for a long time. The aim of this study is to examine the AM potential of autochthonous Ganoderma species (G. applanatum, G. [...] Read more.

Ganoderma species have been recognized as potential antimicrobial (AM) agents and have been used in traditional Chinese medicine (TCM) for a long time. The aim of this study is to examine the AM potential of autochthonous Ganoderma species (G. applanatum, G. lucidum, G. pfeifferi and G. resinaceum) from Serbia. The extraction of fungal material was prepared in different solvents (ethanol—EtOH, water—H₂O, chloroform—CHCl₃). Antibacterial activity (ABA) was determined using disk-diffusion, agar-well diffusion, and micro-dilution method, while for antifungal properties disk-diffusion and pour plate method were applied. Antiviral activity was tested on model DNA virus LK3 and determined by plaque assay. Statistical PCA analysis was applied for detection of correlation effects of phenolics and AM activities, while LC-MS/MS was performed for phenolics quantification. G. resinaceum CHCl₃ extract expressed the most potent ABA against P. aeruginosa (MIC = 6.25 mg/mL), probably due to presence of flavonoids and 2,5-dihydroxybenzoic acid. Among H₂O extracts, the highest ABA was determined for G. pfeifferi against both E. coli and S. aureus (21 and 19 mm, respectively). EtOH extracts of G. pfeifferi and G. resinaceum were the most effective against A. niger (23.8 and 20.15 mm, respectively), with special impact of phenolic acids and flavonoid isorhamnetin, while C. albicans showed the lowest susceptibility. The most potent antiviral inhibitor was G. lucidum (70.73% growth inhibition) due to the high amount of phenolic acids. To the best of our knowledge, this is the first report of a methodical AM profile of G. pfeifferi and G. resinaceum from the Balkan region including PCA analysis. Full article

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

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2 pages, 167 KiB

Open AccessEditorial

Special Issue: New Insights into Protein Glycosylation

by Yuuki Kurebayashi and Hideyuki Takeuchi

Molecules 2023, 28(7), 3263; https://doi.org/10.3390/molecules28073263 - 6 Apr 2023

Cited by 1 | Viewed by 1550

Abstract

Protein glycosylation is a general post-translational modification pathway that controls various biological functions including protein trafficking, cell adhesion, and protein-ligand interaction [...] Full article

(This article belongs to the Special Issue New Insights into Protein Glycosylation)

14 pages, 4387 KiB

Open AccessArticle

TiO₂-MXene/PEDOT:PSS Composite as a Novel Electrochemical Sensing Platform for Sensitive Detection of Baicalein

by Shuya Xue, Min Shi, Jinye Wang, Jiapeng Li, Guanwei Peng, Jingkun Xu, Yansha Gao, Xuemin Duan and Limin Lu

Molecules 2023, 28(7), 3262; https://doi.org/10.3390/molecules28073262 - 6 Apr 2023

Cited by 4 | Viewed by 2518

Abstract

In this work, TiO₂-MXene/poly (3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) composite was utilized as an electrode material for the sensitive electrochemical detection of baicalein. The in-situ growth of TiO₂ nanoparticles on the surface of MXene nanosheets can effectively prevent their aggregation, thus presenting [...] Read more.

In this work, TiO₂-MXene/poly (3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) composite was utilized as an electrode material for the sensitive electrochemical detection of baicalein. The in-situ growth of TiO₂ nanoparticles on the surface of MXene nanosheets can effectively prevent their aggregation, thus presenting a significantly large specific surface area and abundant active sites. However, the partial oxidation of MXene after calcination could reduce its conductivity. To address this issue, herein, PEDOT:PSS films were introduced to disperse the TiO₂-MXene materials. The uniform and dense films of PEDOT:PSS not only improved the conductivity and dispersion of TiO₂-MXene but also enhanced its stability and electrocatalytic activity. With the advantages of a composite material, TiO₂-MXene/PEDOT:PSS as an electrode material demonstrated excellent electrochemical sensing ability for baicalein determination, with a wide linear response ranging from 0.007 to 10.0 μM and a lower limit of detection of 2.33 nM. Furthermore, the prepared sensor displayed good repeatability, reproducibility, stability and selectivity, and presented satisfactory results for the determination of baicalein in human urine sample analysis. Full article

(This article belongs to the Special Issue Application of Functional Materials in Analysis and Detection)

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14 pages, 3982 KiB

Open AccessArticle

Probing the Demulsification Mechanism of Emulsion with SPAN Series Based on the Effect of Solid Phase Particles

by Qingchao Cheng, Guangsheng Cao, Yujie Bai, Zhixuan Zhu, Ning Zhang and Dongju Li

Molecules 2023, 28(7), 3261; https://doi.org/10.3390/molecules28073261 - 6 Apr 2023

Cited by 26 | Viewed by 2071

Abstract

The solid particles in the produced fluids from the oil wells treated by compound flooding can greatly stabilize the strength of the interfacial film and enhance the stability of the emulsion, increasing the difficulty of processing these produced fluids on the ground. In [...] Read more.

The solid particles in the produced fluids from the oil wells treated by compound flooding can greatly stabilize the strength of the interfacial film and enhance the stability of the emulsion, increasing the difficulty of processing these produced fluids on the ground. In this paper, the oil phase and the water phase were separated from the SPAN series emulsions by electrical dehydration technology and adding demulsifier agents. The changing trends of the current at both ends of the electrodes were recorded during the process. The efficient demulsification of the emulsion containing solid particles was studied from the perspective of oil-water separation mechanisms. Combined with the method of molecular dynamics simulation, the effect of the addition of a demulsifier on the free movement characteristics of crude oil molecules at the position of the liquid film of the emulsion were further analyzed. The results indicated that the presence of solid particles greatly increased the emulsifying ability of the emulsion and reduced its size. Under the synergistic effect of demulsifier and electric dehydration, the demulsification effect of the emulsion increased significantly, and the demulsification rate could reach more than 82%. The addition of demulsifiers changed the stable surface state of the solid particles. The free movement ability of the surrounding crude oil molecules was enhanced, which led to a decrease in the strength of the emulsion film so that the water droplets in the emulsions were more likely to coalesce and break. These results are of great significance for the efficient treatment of wastewater from oilfields, promoting the sustainability of environment-friendly oilfield development. Full article

(This article belongs to the Special Issue Research Progress of Surfactants)

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12 pages, 1738 KiB

Open AccessArticle

“Green” Extraction and On-Site Rapid Detection of Aflatoxin B1, Zearalenone and Deoxynivalenol in Corn, Rice and Peanut

by Zijing Li, Zepeng Li, Xintong Li, Qi Fan, Yinuo Chen and Guoqing Shi

Molecules 2023, 28(7), 3260; https://doi.org/10.3390/molecules28073260 - 6 Apr 2023

Cited by 2 | Viewed by 2276

Abstract

The common mycotoxins in polluted grains are aflatoxin B1(AFB1), zearalenone (ZEN) and deoxynivalenol (DON). Because of the potential threat to humans and animals, it is necessary to detect mycotoxin contaminants rapidly. At present, later flow immunoassay (LFIA) is one of the most frequently [...] Read more.

The common mycotoxins in polluted grains are aflatoxin B1(AFB1), zearalenone (ZEN) and deoxynivalenol (DON). Because of the potential threat to humans and animals, it is necessary to detect mycotoxin contaminants rapidly. At present, later flow immunoassay (LFIA) is one of the most frequently used methods for rapid analysis. However, multistep sample pretreatment processes and organic solvents are also required to extract mycotoxins from grains. In this study, we developed a one-step and “green” sample pretreatment method without using organic solvents. By combining with LFIA test strips and a handheld detection device, an on-site method for the rapid detection of AFB1, ZEN and DON was developed. The LODs for AFB1, ZEN and DON in corn are 0.90 μg/kg, 7.11 μg/kg and 10.6 μg/kg, respectively, and the working ranges are from 1.25 μg/kg to 40 μg/kg, 20 μg/kg to 2000 μg/kg and 35 μg/kg to 1500 μg/kg, respectively. This method has been successfully applied to the detection of AFB1, ZEN and DON in corn, rice and peanut, with recoveries of 89 ± 3%–106 ± 3%, 86 ± 2%–108 ± 7% and 90 ± 2%–106 ± 10%, respectively. The detection results for the AFB1, ZEN and DON residues in certified reference materials by this method were in good agreement with their certificate values. Full article

(This article belongs to the Special Issue Development of Analytical Methods in Food, Biological and Environmental Samples Determination II)

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18 pages, 3965 KiB

Open AccessArticle

Isotropic and Anisotropic Monolayer Structures in RF Discharge Plasma

by Anastasiya A. Alekseevskaya, Elena V. Vasilieva, Anatoly V. Filippov, Mikhail M. Vasiliev and Oleg F. Petrov

Molecules 2023, 28(7), 3259; https://doi.org/10.3390/molecules28073259 - 6 Apr 2023

Cited by 1 | Viewed by 1383

Abstract

We present the results of an experimental and analytical study of the structural and dynamic properties of a monolayer consisting of dust grains in an electrostatic trap in an RF discharge plasma. The possibility of forming a monolayer with an isotropic distribution for [...] Read more.

We present the results of an experimental and analytical study of the structural and dynamic properties of a monolayer consisting of dust grains in an electrostatic trap in an RF discharge plasma. The possibility of forming a monolayer with an isotropic distribution for interparticle distance and kinetic energy of particles in the structure has been experimentally shown. Isotropy has crucial importance for the study of various processes in such systems, including the kinetics of phase transitions, the formation of directed flows, wave propagation, and others. Full article

(This article belongs to the Section Physical Chemistry)

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13 pages, 4419 KiB

Open AccessArticle

Metabolite Analysis of Alternaria Mycotoxins by LC-MS/MS and Multiple Tools

by Yanli You, Qinghua Hu, Nan Liu, Cuiju Xu, Sunan Lu, Tongcheng Xu and Xin Mao

Molecules 2023, 28(7), 3258; https://doi.org/10.3390/molecules28073258 - 6 Apr 2023

Cited by 5 | Viewed by 2803

Abstract

Alternaria fungi are widely distributed plant pathogens that invade crop products, causing significant economic damage. In addition, toxic secondary metabolites produced by the fungi can also endanger consumers. Many of these secondary metabolites are chemically characterized as mycotoxins. In this study, Q Exactive [...] Read more.

Alternaria fungi are widely distributed plant pathogens that invade crop products, causing significant economic damage. In addition, toxic secondary metabolites produced by the fungi can also endanger consumers. Many of these secondary metabolites are chemically characterized as mycotoxins. In this study, Q Exactive Orbitrap mass spectrometry was used for the non-targeted analysis of the metabolome of seven Alternaria isolates cultured on Potato Carrot Agar (PCA), Potato Dextrose Agar (PDA) and Potato Sucrose Agar (PSA) medium. Due to the difficulty of detecting modified toxins, an analytical strategy with multiple visual analysis tools was also used to determine the presence of sulfate conjugated toxins, as well as to visualize the molecular network of Alternaria toxins. The results show that PSA medium exhibits more advantageous properties for the culture of Alternaria, with more toxigenic species and quantities and more obvious metabolic pathways. Based on high-resolution tandem mass spectrometry (MS/MS) data, the mycotoxins and their metabolites were mainly clustered into four groups: alternariol (AOH)/alternariol monomethyl ether (AME)/altenusin (ALU)/altenuene (ALT)/dehydroaltenusin (DHA)/Desmethyldehydroaltenusin (DMDA) families, Altertoxin-I (ATX-I) family, tentoxin (TEN) family and tenuazonic acid (TeA) family. Moreover, the PSA medium is more suitable for the accumulation of AOH, AME, ALU, ALT, DHA and DMDA, while the PDA medium is more suitable for the accumulation of ATX-I, TEN and TeA. This research may provide theoretical support for the metabolomics study of Alternaria. Full article

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12 pages, 1739 KiB

Open AccessArticle

Benchmark Study on Phosphorescence Energies of Anthraquinone Compounds: Comparison between TDDFT and UDFT

by Yujie Guo, Lingyu Zhang and Zexing Qu

Molecules 2023, 28(7), 3257; https://doi.org/10.3390/molecules28073257 - 5 Apr 2023

Cited by 2 | Viewed by 1653

Abstract

Phosphorescent material is widely used in light-emitting devices and in the monitoring of cell phenomena. Anthraquinone compounds (AQs), as important phosphorescent materials, have potential applications as emitters for highly efficient organic light-emitting diodes (OLEDs). Therefore, the accurate calculation of the phosphorescence energy of [...] Read more.

Phosphorescent material is widely used in light-emitting devices and in the monitoring of cell phenomena. Anthraquinone compounds (AQs), as important phosphorescent materials, have potential applications as emitters for highly efficient organic light-emitting diodes (OLEDs). Therefore, the accurate calculation of the phosphorescence energy of anthraquinone compounds is particularly important. This study mainly analyzes the phosphorescence energy calculation method of anthraquinone compounds. The time-dependent density functional theory (TDDFT) and the unrestricted density functional theory (UDFT) with seven functionals are selected to calculate the phosphorescence of AQs, taking the high-precision coupled-cluster singles and doubles (CC2) method as a reference. The results showed that the mean unsigned error (MUE) of UDFT was 0.14 eV, which was much smaller than that of TDDFT at 0.29 eV. Therefore, UDFT was more suitable for calculating the phosphorescence energy of AQs. The results obtained by different functionals indicate that the minimum MUE obtained by M06-2X was 0.14 eV. More importantly, the diffuse function in the basis set played an important role in calculating the phosphorescence energy in the M06-HF functional. In the BDBT, FBDBT, and BrBDBT, when M06-HF selected the basis set containing a diffuse function, the differences with CC2 was 0.02 eV, which is much smaller than the one obtained without a diffuse function at 0.80 eV. These findings might be of great significance for the future study of the phosphorescence energy of organic molecules. Full article

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

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14 pages, 3286 KiB

Open AccessArticle

Synthesis and Elimination Pathways of 1-Methanesulfonyl-1,2-dihydroquinoline Sulfonamides

by Ebenezer Ametsetor, Kwabena Fobi and Richard A. Bunce

Molecules 2023, 28(7), 3256; https://doi.org/10.3390/molecules28073256 - 5 Apr 2023

Cited by 1 | Viewed by 1846

Abstract

A series of new Morita–Baylis–Hillman acetates were prepared and reacted with methanesulfonamide (K₂CO₃, DMF, 23 °C) to produce tertiary dihydroquinoline sulfonamides in high yields. Subsequent efforts to eliminate the methylsulfonyl group from these derivatives (K₂CO₃, [...] Read more.

A series of new Morita–Baylis–Hillman acetates were prepared and reacted with methanesulfonamide (K₂CO₃, DMF, 23 °C) to produce tertiary dihydroquinoline sulfonamides in high yields. Subsequent efforts to eliminate the methylsulfonyl group from these derivatives (K₂CO₃, DMF, 90 °C) as a route to quinolines were met with mixed results. Although dihydroquinoline sulfonamides prepared from ethyl acrylate and acrylonitrile generally underwent elimination to give excellent yields of quinolines, those generated from 3-buten-2-one failed to undergo elimination and instead decomposed. The failure of these ketone substrates to aromatize presumably derives from the enolizable methyl ketone at C-3. Finally, the attempted aromatization of the acrylate-derived 6,7-difluoro-1,2-dihydroquinoline sulfonamide demonstrated that other interesting processes could occur in preference to the desired elimination. Full article

(This article belongs to the Special Issue Molecules in 2023)

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18 pages, 350 KiB

Open AccessArticle

Mineral, Nutritional, and Phytochemical Composition and Baking Properties of Teff and Watermelon Seed Flours

by Anna Jaroszewska, Dariusz Jedrejek, Magdalena Sobolewska, Iwona Kowalska and Małgorzata Dzięcioł

Molecules 2023, 28(7), 3255; https://doi.org/10.3390/molecules28073255 - 5 Apr 2023

Cited by 4 | Viewed by 3670

Abstract

Demonstrated limitations in the mineral and nutritional composition of refined flours have led to calls for the possibility of enriching them with health-promoting supplements, such as high-value non-cereal seeds. Teff and watermelon seeds have been found suitable for the production of gluten-free flour, [...] Read more.

Demonstrated limitations in the mineral and nutritional composition of refined flours have led to calls for the possibility of enriching them with health-promoting supplements, such as high-value non-cereal seeds. Teff and watermelon seeds have been found suitable for the production of gluten-free flour, but so far, their potential to enrich conventional baking flours has not been comprehensively studied. Hence, the present study aimed at farinographic evaluation of dough based on refined wheat flour with additions of whole white teff (TF) and watermelon seed (WSF) and pomace (DWSF) flours (tested levels 10%, 20%, and 30%), as well as possibly extensive chemical characterization of the plant material tested, including LC-MS/MS, GC-MS, total phenolics, flavonoids, melatonin, and antioxidant potential. Most of the rheological traits were improved in the flour mixtures compared to the base white flour: development time and quality number (above 1.6-fold increase), softening and stability time (up to 1.3-fold change), and water absorption (up to 6%). Overall, the best results were achieved after the addition of watermelon seed pomace. The DWSF material was characterized by the highest levels of P, Mg, Na (7.5, 1.7, 0.4 g/kg, respectively), and Fe and Zn (124 and 27 mg/kg), while TF was the richest in Ca (0.9 g/kg) and Mn (43 mg/kg). Protein and fat levels were significantly higher in watermelon seeds compared to teff (about double and up to 10-fold, respectively). Phytochemical analyses highlighted the abundance of phenolics, especially flavones, in TF, WSF and DWSF flours (244, 93, and 721 mg/kg, respectively). However, the value of total polyphenols was low in all materials (<2 mg GAE/g), which also correlates with the low antioxidant potential of the samples. Watermelon seed pomace was characterized by significantly higher melatonin concentration (60 µg/kg) than teff (3.5 µg/kg). This study provides new information on the chemical composition and application opportunities of teff and watermelon seeds. Full article

(This article belongs to the Collection Advances in Food Chemistry)

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11 pages, 1513 KiB

Open AccessArticle

The Preparation and Physiochemical Characterization of Tenebrio molitor Chitin Using Alcalase

by Hyemi Kim, Hyeongyeong Kim, Yejin Ahn, Ki-Bae Hong, In-Woo Kim, Ra-Yeong Choi, Hyung Joo Suh and Sung Hee Han

Molecules 2023, 28(7), 3254; https://doi.org/10.3390/molecules28073254 - 5 Apr 2023

Cited by 10 | Viewed by 2278

Abstract

Chitin is mostly produced from crustaceans, but it is difficult to supply raw materials due to marine pollution, and the commonly used chemical chitin extraction method is not environmentally friendly. Therefore, this study aims to establish a chitin extraction process using enzymes and [...] Read more.

Chitin is mostly produced from crustaceans, but it is difficult to supply raw materials due to marine pollution, and the commonly used chemical chitin extraction method is not environmentally friendly. Therefore, this study aims to establish a chitin extraction process using enzymes and to develop edible insect-derived chitin as an eco-friendly new material. The response surface methodology (RSM) was used to determine the optimal conditions for enzymatic hydrolysis. The optimal conditions for enzymatic hydrolysis by RSM were determined to be the substrate concentration (7.5%), enzyme concentration (80 μL/g), and reaction time (24 h). The solubility and DDA of the mealworm chitosan were 45% and 37%, respectively, and those of the commercial chitosan were 61% and 57%, respectively. In regard to the thermodynamic properties, the exothermic peak of mealworm chitin was similar to that of commercial chitin. In the FT-IR spectrum, a band was observed in mealworm chitin corresponding to the C=O of the NHCOCH₃ group at 1645 cm⁻¹, but this band showed low-intensity C=O in the mealworm chitosan due to deacetylation. Collectively, mealworm chitosan shows almost similar physical and chemical properties to commercial chitosan. Therefore, it is shown that an eco-friendly process can be introduced into chitosan production by using enzyme-extracted mealworms for chitin/chitosan production. Full article

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17 pages, 1648 KiB

Open AccessReview

On the Nature of the Partial Covalent Bond between Noble Gas Elements and Noble Metal Atoms

by Ranita Pal and Pratim Kumar Chattaraj

Molecules 2023, 28(7), 3253; https://doi.org/10.3390/molecules28073253 - 5 Apr 2023

Cited by 3 | Viewed by 2751

Abstract

This article provides a discussion on the nature of bonding between noble gases (Ng) and noble metals (M) from a quantum chemical perspective by investigating compounds such as NgMY (Y=CN, O, NO₃, SO₄, CO₃), [NgM−(bipy)]+, NgMCCH, and [...] Read more.

This article provides a discussion on the nature of bonding between noble gases (Ng) and noble metals (M) from a quantum chemical perspective by investigating compounds such as NgMY (Y=CN, O, NO₃, SO₄, CO₃), [NgM−(bipy)]+, NgMCCH, and MCCNgH complexes, where M=Cu, Ag, Au and Ng=Kr−Rn, with some complexes containing the lighter noble gas atoms as well. Despite having very low chemical reactivity, noble gases have been observed to form weak bonds with noble metals such as copper, gold, and silver. In this study, we explore the factors that contribute to this unusual bonding behavior, including the electronic structure of the atoms involved and the geometric configuration of the concerned fragments. We also investigate the metastable nature of the resulting complexes by studying the energetics of their possible dissociation and internal isomerization channels. The noble gas-binding ability of the bare metal cyanides are higher than most of their bromide counterparts, with CuCN and AgCN showing higher affinity than their chloride analogues as well. In contrast, the oxides seem to have lower binding power than their corresponding halides. In the oxide and the bipyridyl complexes, the Ng-binding ability follows the order Au > Cu > Ag. The dissociation energies calculated, considering the zero-point energy correction for possible dissociation channels, increase as we move down the noble gas group. The bond between the noble gases and the noble metals in the complexes are found to have comparable weightage of orbital and electrostatic interactions, suggestive of a partial covalent nature. The same is validated from the topological analysis of electron density. Full article

(This article belongs to the Special Issue Fundamental Aspects of Chemical Bonding)

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Molecules, Volume 28, Issue 7 (April-1 2023) – 404 articles

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