Molecules

27 pages, 1158 KiB

Open AccessReview

Supramolecular Complexation of Carbohydrates for the Bioavailability Enhancement of Poorly Soluble Drugs

by Eunae Cho¹ and Seunho Jung^1,2,3,*

¹ Center for Biotechnology Research in UBITA (CBRU), Institute for Ubiquitous Information Technology and Applications (UBITA), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Korea

² Microbial Carbohydrate Resource Bank (MBRC), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Korea

³ Department of Bioscience and Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Korea

Molecules 2015, 20(10), 19620-19646; https://doi.org/10.3390/molecules201019620 - 27 Oct 2015

Cited by 46 | Viewed by 8561

Abstract

In this review, a comprehensive overview of advances in the supramolecular complexes of carbohydrates and poorly soluble drugs is presented. Through the complexation process, poorly soluble drugs could be efficiently delivered to their desired destinations. Carbohydrates, the most abundant biomolecules, have diverse physicochemical [...] Read more.

In this review, a comprehensive overview of advances in the supramolecular complexes of carbohydrates and poorly soluble drugs is presented. Through the complexation process, poorly soluble drugs could be efficiently delivered to their desired destinations. Carbohydrates, the most abundant biomolecules, have diverse physicochemical properties owing to their inherent three-dimensional structures, hydrogen bonding, and molecular recognition abilities. In this regard, oligosaccharides and their derivatives have been utilized for the bioavailability enhancement of hydrophobic drugs via increasing the solubility or stability. By extension, polysaccharides and their derivatives can form self-assembled architectures with poorly soluble drugs and have shown increased bioavailability in terms of the sustained or controlled drug release. These supramolecular systems using carbohydrate will be developed consistently in the field of pharmaceutical and medical application. Full article

(This article belongs to the Section Medicinal Chemistry)

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15 pages, 873 KiB

Open AccessArticle

A Simple, Effective, Green Method for the Regioselective 3-Acylation of Unprotected Indoles

by Phuong Hoang Tran¹, Hai Ngoc Tran¹, Poul Erik Hansen^2,*, Mai Hoang Ngoc Do¹ and Thach Ngoc Le¹

¹ Department of Organic Chemistry, Faculty of Chemistry, University of Science, Vietnam National University, Ho Chi Minh City 70000, Vietnam

² Department of Science, Systems and Models, Roskilde University, POB 260, Roskilde DK-4000, Denmark

Molecules 2015, 20(10), 19605-19619; https://doi.org/10.3390/molecules201019605 - 27 Oct 2015

Cited by 15 | Viewed by 7914

Abstract

A fast and green method is developed for regioselective acylation of indoles in the 3-position without the need for protection of the NH position. The method is based on Friedel-Crafts acylation using acid anhydrides. The method has been optimized, and Y(OTf)₃ in [...] Read more.

A fast and green method is developed for regioselective acylation of indoles in the 3-position without the need for protection of the NH position. The method is based on Friedel-Crafts acylation using acid anhydrides. The method has been optimized, and Y(OTf)₃ in catalytic amounts is found to be the best catalyst together with the commercially available ionic liquid [BMI]BF₄ (1-butyl-3-methylimidazolium tetrafluoro-borate) as solvent. The reaction is completed in a very short time using monomode microwave irradiation. The catalyst can be reused up to four times without significant loss of activity. A range of substituted indoles are investigated as substrates, and thirteen new compounds have been synthesized. Full article

(This article belongs to the Special Issue Ionic Liquids in Organic Synthesis)

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17 pages, 3707 KiB

Open AccessArticle

Elevated Expression and Pro-Inflammatory Activity of IL-36 in Patients with Systemic Lupus Erythematosus

by Man Chu^1,2,†, Chun Kwok Wong^1,2,3,†, Zhe Cai^1,2

, Jie Dong^1,2, Delong Jiao^1,2, Ngar Woon Kam^2,4, Christopher Wai Kei Lam⁵ and Lai Shan Tam^2,4,*

¹ Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong, China

² Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen 518057, China

³ State Key Laboratory of Phytochemistry and Plant Resources in West China, Institute of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong, China

⁴ Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, China

⁵ State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Taipa, Macau

^† These authors contributed equally to this work.

Molecules 2015, 20(10), 19588-19604; https://doi.org/10.3390/molecules201019588 - 27 Oct 2015

Cited by 51 | Viewed by 8578

Abstract

We investigated the expression and proinflammatory activity of interleukin (IL)-36 in patients with systemic lupus erythematosus (SLE). The expression level of IL-36, its putative receptors and the frequency of CD19⁺CD24^highCD27⁺ regulatory B (Breg) lymphocytes of peripheral blood from [...] Read more.

We investigated the expression and proinflammatory activity of interleukin (IL)-36 in patients with systemic lupus erythematosus (SLE). The expression level of IL-36, its putative receptors and the frequency of CD19⁺CD24^highCD27⁺ regulatory B (Breg) lymphocytes of peripheral blood from 43 SLE patients and 16 normal control (NC) subjects were studied using ELISA and flow cytometry. Plasma cytokines/chemokines and ex vivo productions of cytokine/chemokine from peripheral blood mononuclear cells (PBMC) stimulated with recombinant IL-36 were determined by Luminex multiplex assay. Plasma concentrations of IL-36α, IL-36γ and the proportions of circulating IL-36R-positive CD19⁺ B lymphocytes in total B lymphocytes and PBMC were significantly increased in active SLE patients compared with NC (all p < 0.05). Plasma IL-36α and IL-36γ correlated positively with SLE disease activity and elevated plasma IL-10 concentration (all p < 0.05). The frequencies of circulating Breg lymphocytes in total B lymphocytes and PBMC were significantly decreased in both inactive and active SLE patients compared with NC (all p < 0.01). The frequency of Breg lymphocytes in total B lymphocytes correlated negatively with the proportion of IL-36R-positive B lymphocytes (p < 0.05). IL-36α exerted substantial proinflammatory effect in PBMC from SLE patients by inducing the production of IL-6 and CXCL8. Upon stimulation with IL-36α and IL-36γ, ex vivo productions of IL-6 and CXCL8 were significantly increased in SLE patients compared with NC (all p < 0.05). This cross-sectional study demonstrated that over expression of circulating IL-36α may exert a proinflammatory effect as observed in human SLE. Full article

(This article belongs to the Section Medicinal Chemistry)

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17 pages, 2280 KiB

Open AccessArticle

Multivariate Quantification of the Solid State Phase Composition of Co-Amorphous Naproxen-Indomethacin

by Andreas Beyer¹, Holger Grohganz²

, Korbinian Löbmann²

, Thomas Rades²

and Claudia S. Leopold^1,*

¹ Division of Pharmaceutical Technology, University of Hamburg, Hamburg 20146, Germany

² Department of Pharmacy, University of Copenhagen, Copenhagen 2100, Denmark

Molecules 2015, 20(10), 19571-19587; https://doi.org/10.3390/molecules201019571 - 27 Oct 2015

Cited by 9 | Viewed by 8121

Abstract

To benefit from the optimized dissolution properties of active pharmaceutical ingredients in their amorphous forms, co-amorphisation as a viable tool to stabilize these amorphous phases is of both academic and industrial interest. Reports dealing with the physical stability and recrystallization behavior of co-amorphous [...] Read more.

To benefit from the optimized dissolution properties of active pharmaceutical ingredients in their amorphous forms, co-amorphisation as a viable tool to stabilize these amorphous phases is of both academic and industrial interest. Reports dealing with the physical stability and recrystallization behavior of co-amorphous systems are however limited to qualitative evaluations based on the corresponding X-ray powder diffractograms. Therefore, the objective of the study was to develop a quantification model based on X-ray powder diffractometry (XRPD), followed by a multivariate partial least squares regression approach that enables the simultaneous determination of up to four solid state fractions: crystalline naproxen, γ-indomethacin, α-indomethacin as well as co-amorphous naproxen-indomethacin. For this purpose, a calibration set that covers the whole range of possible combinations of the four components was prepared and analyzed by XRPD. In order to test the model performances, leave-one-out cross validation was performed and revealed root mean square errors of validation between 3.11% and 3.45% for the crystalline molar fractions and 5.57% for the co-amorphous molar fraction. In summary, even four solid state phases, involving one co-amorphous phase, can be quantified with this XRPD data-based approach. Full article

(This article belongs to the Collection Poorly Soluble Drugs)

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17 pages, 936 KiB

Open AccessReview

Starch Modification by Organic Acids and Their Derivatives: A Review

by Đurđica Ačkar^1,†

, Jurislav Babić^1,*

, Antun Jozinović^1,†

, Borislav Miličević^1,†, Stela Jokić^1,†, Radoslav Miličević^2,†, Marija Rajič^1,† and Drago Šubarić^1,†

¹ Department of Food Technology, Faculty of Food Technology, Josip Juraj Strossmayer University of Osijek, Franje Kuhača 20, Osijek 31000, Croatia

² Faculty of Technology Tuzla, University of Tuzla, Univerzitetska 8, Tuzla 75000, Bosnia and Herzegovina

^† These authors contributed equally to this work.

Molecules 2015, 20(10), 19554-19570; https://doi.org/10.3390/molecules201019554 - 27 Oct 2015

Cited by 149 | Viewed by 20006

Abstract

Starch has been an inexhaustible subject of research for many decades. It is an inexpensive, readily-available material with extensive application in the food and processing industry. Researchers are continually trying to improve its properties by different modification procedures and expand its application. What [...] Read more.

Starch has been an inexhaustible subject of research for many decades. It is an inexpensive, readily-available material with extensive application in the food and processing industry. Researchers are continually trying to improve its properties by different modification procedures and expand its application. What is mostly applied in this view are their chemical modifications, among which organic acids have recently drawn the greatest attention, particularly with respect to the application of starch in the food industry. Namely, organic acids naturally occur in many edible plants and many of them are generally recognized as safe (GRAS), which make them ideal modification agents for starch intended for the food industry. The aim of this review is to give a short literature overview of the progress made in the research of starch esterification, etherification, cross-linking, and dual modification with organic acids and their derivatives. Full article

(This article belongs to the Section Natural Products Chemistry)

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14 pages, 2287 KiB

Open AccessArticle

Unique Reactivity of Transition Metal Atoms Embedded in Graphene to CO, NO, O₂ and O Adsorption: A First-Principles Investigation

by Minmin Chu, Xin Liu^*

, Yanhui Sui^*, Jie Luo and Changgong Meng^*

School of Chemistry and State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China

Molecules 2015, 20(10), 19540-19553; https://doi.org/10.3390/molecules201019540 - 27 Oct 2015

Cited by 15 | Viewed by 6738

Abstract

Taking the adsorption of CO, NO, O₂ and O as probes, we investigated the electronic structure of transition metal atoms (TM, TM = Fe, Co, Ni, Cu and Zn) embedded in graphene by first-principles-based calculations. We showed that these TM atoms can [...] Read more.

Taking the adsorption of CO, NO, O₂ and O as probes, we investigated the electronic structure of transition metal atoms (TM, TM = Fe, Co, Ni, Cu and Zn) embedded in graphene by first-principles-based calculations. We showed that these TM atoms can be effectively stabilized on monovacancy defects on graphene by forming plausible interactions with the C atoms associated with dangling bonds. These interactions not only give rise to high energy barriers for the diffusion and aggregation of the embedded TM atoms to withstand the interference of reaction environments, but also shift the energy levels of TM-d states and regulate the reactivity of the embedded TM atoms. The adsorption of CO, NO, O₂ and O correlates well with the weight averaged energy level of TM-d states, showing the crucial role of interfacial TM-C interactions on manipulating the reactivity of embedded TM atoms. These findings pave the way for the developments of effective monodispersed atomic TM composites with high stability and desired performance for gas sensing and catalytic applications. Full article

(This article belongs to the Section Medicinal Chemistry)

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14 pages, 1196 KiB

Open AccessArticle

Fluorescence and Docking Studies of the Interaction between Human Serum Albumin and Pheophytin

by Otávio Augusto Chaves^1,†, Ana Paula de O. Amorim^1,†, Larissa H. E. Castro^1,†, Carlos Mauricio R. Sant’Anna^1,†, Márcia C. C. De Oliveira^1,†, Dari Cesarin-Sobrinho^1,†, José Carlos Netto-Ferreira^1,2,† and Aurélio B. B. Ferreira^1,*

¹ Departamento de Química, Universidade Federal Rural do Rio de Janeiro, BR 465, km 47, 23890-000 Seropédica-RJ, Brazil

² Instituto Nacional de Metrologia, Qualidade e Tecnologia-INMETRO, Divisão de Metrologia Química, 25250-020 Duque de Caxias-RJ, Brazil

^† These authors contributed equally to this work.

Molecules 2015, 20(10), 19526-19539; https://doi.org/10.3390/molecules201019526 - 27 Oct 2015

Cited by 91 | Viewed by 10957

Abstract

In the North of Brazil (Pará and Amazonas states) the leaves of the plant Talinum triangulare (popular: cariru) replace spinach as food. From a phytochemical point of view, they are rich in compounds of the group of pheophytins. These substances, related to [...] Read more.

In the North of Brazil (Pará and Amazonas states) the leaves of the plant Talinum triangulare (popular: cariru) replace spinach as food. From a phytochemical point of view, they are rich in compounds of the group of pheophytins. These substances, related to chlorophyll, have photophysical properties that give them potential application in photodynamic therapy. Human serum albumin (HSA) is one of the main endogenous vehicles for biodistribution of molecules by blood plasma. Association constants and thermodynamic parameters for the interaction of HSA with pheophytin from Talinum triangulare were studied by UV-Vis absorption, fluorescence techniques, and molecular modeling (docking). Fluorescence quenching of the HSA’s internal fluorophore (tryptophan) at temperatures 296 K, 303 K, and 310 K, resulted in values for the association constants of the order of 10⁴ L∙mol⁻¹, indicating a moderate interaction between the compound and the albumin. The negative values of ΔG° indicate a spontaneous process; ΔH° = 15.5 kJ∙mol⁻¹ indicates an endothermic process of association and ΔS° = 0.145 kJ∙mol⁻¹∙K⁻¹ shows that the interaction between HSA and pheophytin occurs mainly by hydrophobic factors. The observed Trp fluorescence quenching is static: there is initial non-fluorescent association, in the ground state, HSA:Pheophytin. Possible solution obtained by a molecular docking study suggests that pheophytin is able to interact with HSA by means of hydrogen bonds with three lysine and one arginine residues, whereas the phytyl group is inserted in a hydrophobic pocket, close to Trp-214. Full article

(This article belongs to the Section Photochemistry)

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37 pages, 1537 KiB

Open AccessReview

Antioxidants of Edible Mushrooms

by Maja Kozarski¹, Anita Klaus², Dragica Jakovljevic³, Nina Todorovic³, Jovana Vunduk², Predrag Petrović⁴, Miomir Niksic², Miroslav M. Vrvic^3,5 and Leo Van Griensven^6,*

¹ Department for Chemistry and Biochemistry, Faculty of Agriculture, University of Belgrade, Nemanjina 6, Belgrade 11080, Serbia

² Department for Industrial Microbiology, Faculty of Agriculture, University of Belgrade, Nemanjina 6, Belgrade 11080, Serbia

³ Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Njegoseva 12, Belgrade 11001, Serbia

⁴ Institute of Chemical Engineering, Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, Belgrade 11060, Serbia

⁵ Faculty of Chemistry, University of Belgrade, Studentski trg 12–16, Belgrade 11000, Serbia

⁶ Plant Research International, Wageningen University and Research Centre, Droevendaalsesteeg 1, Wageningen 6700 AA, The Netherlands

Molecules 2015, 20(10), 19489-19525; https://doi.org/10.3390/molecules201019489 - 27 Oct 2015

Cited by 310 | Viewed by 26690

Abstract

Oxidative stress caused by an imbalanced metabolism and an excess of reactive oxygen species (ROS) lead to a range of health disorders in humans. Our endogenous antioxidant defense mechanisms and our dietary intake of antioxidants potentially regulate our oxidative homeostasis. Numerous synthetic antioxidants [...] Read more.

Oxidative stress caused by an imbalanced metabolism and an excess of reactive oxygen species (ROS) lead to a range of health disorders in humans. Our endogenous antioxidant defense mechanisms and our dietary intake of antioxidants potentially regulate our oxidative homeostasis. Numerous synthetic antioxidants can effectively improve defense mechanisms, but because of their adverse toxic effects under certain conditions, preference is given to natural compounds. Consequently, the requirements for natural, alternative sources of antioxidant foods identified in edible mushrooms, as well as the mechanistic action involved in their antioxidant properties, have increased rapidly. Chemical composition and antioxidant potential of mushrooms have been intensively studied. Edible mushrooms might be used directly in enhancement of antioxidant defenses through dietary supplementation to reduce the level of oxidative stress. Wild or cultivated, they have been related to significant antioxidant properties due to their bioactive compounds, such as polyphenols, polysaccharides, vitamins, carotenoids and minerals. Antioxidant and health benefits, observed in edible mushrooms, seem an additional reason for their traditional use as a popular delicacy food. This review discusses the consumption of edible mushrooms as a powerful instrument in maintaining health, longevity and life quality. Full article

(This article belongs to the Special Issue Antioxidants—A Risk-Benefit Analysis for Health)

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26 pages, 10701 KiB

Open AccessArticle

Comparative Study of the Optical and Textural Properties of Tetrapyrrole Macrocycles Trapped Within ZrO₂, TiO₂, and SiO₂ Translucent Xerogels

by Eduardo Salas-Bañales, R. Iris Y. Quiroz-Segoviano, Luis Antonio Díaz-Alejo, Fernando Rojas-González

, Alberto Estrella-González, Antonio Campero and Miguel A. García-Sánchez^*

Department of Chemistry, Universidad Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco 186, Col. Vicentina, Mexico, D.F. 09340, Mexico

Molecules 2015, 20(10), 19463-19488; https://doi.org/10.3390/molecules201019463 - 23 Oct 2015

Cited by 7 | Viewed by 7658

Abstract

The entrapping of physicochemical active molecules inside mesoporous networks is an appealing field of research due to the myriad of potential applications in optics, photocatalysis, chemical sensing, and medicine. One of the most important reasons for this success is the possibility of optimizing [...] Read more.

The entrapping of physicochemical active molecules inside mesoporous networks is an appealing field of research due to the myriad of potential applications in optics, photocatalysis, chemical sensing, and medicine. One of the most important reasons for this success is the possibility of optimizing the properties that a free active species displays in solution but now trapped inside a solid substrate. Additionally it is possible to modulate the textural characteristics of substrates, such as pore size, specific surface area, polarity and chemical affinity of the surface, toward the physical or chemical adhesion of a variety of adsorbates. In the present document, two kinds of non-silicon metal alkoxides, Zr and Ti, are employed to prepare xerogels containing entrapped tetrapyrrolic species that could be inserted beforehand in analogue silica systems. The main goal is to develop efficient methods for trapping or binding tetrapyrrole macrocycles inside TiO₂ and ZrO₂ xerogels, while comparing the properties of these systems against those of the SiO₂ analogues. Once the optimal synthesis conditions for obtaining translucent monolithic xerogels of ZrO₂ and TiO₂ networks were determined, it was confirmed that these substrates allowed the entrapment, in monomeric form, of macrocycles that commonly appear as aggregates within the SiO₂ network. From these experiments, it could be determined that the average pore diameters, specific surface areas, and water sorption capacities depicted by each one of these substrates, are a consequence of their own nature combined with the particular structure of the entrapped tetrapyrrole macrocycle. Furthermore, the establishment of covalent bonds between the intruding species and the pore walls leads to the obtainment of very similar pore sizes in the three different metal oxide (Ti, Zr, and Si) substrates as a consequence of the templating effect of the encapsulated species. Full article

(This article belongs to the Special Issue Tetrapyrroles, Porphyrins and Phthalocyanines)

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14 pages, 795 KiB

Open AccessCommunication

Selective Halogen-Lithium Exchange of 1,2-Dihaloarenes for Successive [2+4] Cycloadditions of Arynes and Isobenzofurans

by Shohei Eda and Toshiyuki Hamura^*

Department of Applied Chemistry for Environment, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan

Molecules 2015, 20(10), 19449-19462; https://doi.org/10.3390/molecules201019449 - 23 Oct 2015

Cited by 17 | Viewed by 9820

Abstract

Successive [2+4] cycloadditions of arynes and isobenzofurans by site-selective halogen-lithium exchange of 1,2-dihaloarenes were developed, allowing the rapid construction of polycyclic compounds which serve as a useful synthetic intermediates for the preparation of various polyacene derivatives. Full article

(This article belongs to the Special Issue Development and Application of Aryne Chemistry in Organic Synthesis)

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16 pages, 759 KiB

Open AccessReview

The Multiple Roles of Microrna-223 in Regulating Bone Metabolism

by Yong Xie^1,†, Lihai Zhang^1,†, Yanpan Gao², Wei Ge^2,* and Peifu Tang^1,*

¹ Department of Orthopedics, General Hospital of Chinese PLA, Beijing 100853, China

² National Key Laboratory of Medical Molecular Biology, Department of Immunology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Beijing 100005, China

^† These authors contributed equally to this work.

Molecules 2015, 20(10), 19433-19448; https://doi.org/10.3390/molecules201019433 - 23 Oct 2015

Cited by 41 | Viewed by 8513

Abstract

Bone metabolism is a lifelong process for maintaining skeletal system homeostasis, which is regulated by bone-resorbing osteoclasts and bone-forming osteoblasts. Aberrant differentiation of osteoclasts and osteoblasts leads to imbalanced bone metabolism, resulting in ossification and osteolysis diseases. MicroRNAs (miRNAs) are pivotal factors in [...] Read more.

Bone metabolism is a lifelong process for maintaining skeletal system homeostasis, which is regulated by bone-resorbing osteoclasts and bone-forming osteoblasts. Aberrant differentiation of osteoclasts and osteoblasts leads to imbalanced bone metabolism, resulting in ossification and osteolysis diseases. MicroRNAs (miRNAs) are pivotal factors in regulating bone metabolism via post-transcriptional inhibition of target genes. Recent studies have revealed that miR-223 exerts multiple effects on bone metabolism, especially in the processes of osteoclast and osteoblasts differentiation. In this review, we highlight the roles of miR-223 during the processes of osteoclast and osteoblast differentiation, as well as the potential clinical applications of miR-223 in bone metabolism disorders. Full article

(This article belongs to the Section Molecular Diversity)

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27 pages, 892 KiB

Open AccessReview

Effects of Flavonoids from Food and Dietary Supplements on Glial and Glioblastoma Multiforme Cells

by Marko Vidak^*, Damjana Rozman and Radovan Komel

Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Vrazov Trg 2, SI-1000 Ljubljana, Slovenia

Molecules 2015, 20(10), 19406-19432; https://doi.org/10.3390/molecules201019406 - 23 Oct 2015

Cited by 43 | Viewed by 11488

Abstract

Quercetin, catechins and proanthocyanidins are flavonoids that are prominently featured in foodstuffs and dietary supplements, and may possess anti-carcinogenic activity. Glioblastoma multiforme is the most dangerous form of glioma, a malignancy of the brain connective tissue. This review assesses molecular structures of these [...] Read more.

Quercetin, catechins and proanthocyanidins are flavonoids that are prominently featured in foodstuffs and dietary supplements, and may possess anti-carcinogenic activity. Glioblastoma multiforme is the most dangerous form of glioma, a malignancy of the brain connective tissue. This review assesses molecular structures of these flavonoids, their importance as components of diet and dietary supplements, their bioavailability and ability to cross the blood-brain barrier, their reported beneficial health effects, and their effects on non-malignant glial as well as glioblastoma tumor cells. The reviewed flavonoids appear to protect glial cells via reduction of oxidative stress, while some also attenuate glutamate-induced excitotoxicity and reduce neuroinflammation. Most of the reviewed flavonoids inhibit proliferation of glioblastoma cells and induce their death. Moreover, some of them inhibit pro-oncogene signaling pathways and intensify the effect of conventional anti-cancer therapies. However, most of these anti-glioblastoma effects have only been observed in vitro or in animal models. Due to limited ability of the reviewed flavonoids to access the brain, their normal dietary intake is likely insufficient to produce significant anti-cancer effects in this organ, and supplementation is needed. Full article

(This article belongs to the Special Issue Dietary Bioactive Compounds: Metabolism, Mechanisms and Translational Significance for Health and Prevention of Diseases)

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13 pages, 781 KiB

Open AccessArticle

A Practical Route for the Preparation of 1,4,7-Triazacyclononanyl Diacetates with a Hydroxypyridinonate Pendant Arm

by Yongkang Gai, Zhongping Hu, Zhao Rong, Xiang Ma^* and Guangya Xiang^*

School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China

Molecules 2015, 20(10), 19393-19405; https://doi.org/10.3390/molecules201019393 - 23 Oct 2015

Cited by 15 | Viewed by 6441

Abstract

The preparation of triazamacrocyclic hydroxypyridinonate (HOPO-TACN) derivatives as potential chelators for metals in biomedical applications was reported. The synthesis is based on a convergent synthetic approach, in which the key intermediate di-tert-butyl-2,2′-(1,4,7-triazonane-1,4-diyl) diacetate was coupled with a hydroxypyridinonate pendant arm. The [...] Read more.

The preparation of triazamacrocyclic hydroxypyridinonate (HOPO-TACN) derivatives as potential chelators for metals in biomedical applications was reported. The synthesis is based on a convergent synthetic approach, in which the key intermediate di-tert-butyl-2,2′-(1,4,7-triazonane-1,4-diyl) diacetate was coupled with a hydroxypyridinonate pendant arm. The method is suitable for rapid syntheses of metal chelator HOPO-TACNs of biomedical interest. Full article

(This article belongs to the Section Organic Chemistry)

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21 pages, 1250 KiB

Open AccessArticle

Purification and Partial Characterization of β-Glucosidase in Chayote (Sechium edule)

by Sergio Espíndola Mateos¹, Carlos Alberto Matías Cervantes¹, Edgar Zenteno³, Marie-Christine Slomianny⁴, Juan Alpuche², Pedro Hernández-Cruz², Ruth Martínez-Cruz², Maria Del Socorro Pina Canseco²

, Eduardo Pérez-Campos^1,2, Manuel Sánchez Rubio¹, Laura Pérez-Campos Mayoral²

and Margarito Martínez-Cruz^1,*

¹ Unidad de Bioquímica e Inmunología, Instituto Tecnológico de Oaxaca, Oaxaca 68030, Mexico

² Centro de Investigación Medicina-UNAM-UABJO, Facultad de Medicina y Cirugía, Universidad Autónoma “Benito Juárez” de Oaxaca, Oaxaca 68050, Mexico

³ Facultad de Medicina de la, Universidad Nacional Autónoma de México, Distrito Federal 04510, Mexico

⁴ Unité Mixte de Recherche CNRS/USTL 8576, Glycobiologie Structurale et Fonctionnelle, Université des Sciences et Technologies de Lille 1, Villeneuve d’Ascq 59655, France

Molecules 2015, 20(10), 19372-19392; https://doi.org/10.3390/molecules201019372 - 23 Oct 2015

Cited by 15 | Viewed by 8505

Abstract

β-Glucosidase (EC 3.2.1.21) is a prominent member of the GH1 family of glycoside hydrolases. The properties of this β-glucosidase appear to include resistance to temperature, urea, and iodoacetamide, and it is activated by 2-ME, similar to other members. β-Glucosidase from chayote (Sechium [...] Read more.

β-Glucosidase (EC 3.2.1.21) is a prominent member of the GH1 family of glycoside hydrolases. The properties of this β-glucosidase appear to include resistance to temperature, urea, and iodoacetamide, and it is activated by 2-ME, similar to other members. β-Glucosidase from chayote (Sechium edule) was purified by ionic-interchange chromatography and molecular exclusion chromatography. Peptides detected by LC-ESI-MS/MS were compared with other β-glucosidases using the BLAST program. This enzyme is a 116 kDa protein composed of two sub-units of 58 kDa and shows homology with Cucumis sativus β-glucosidase (NCBI reference sequence XP_004154617.1), in which seven peptides were found with relative masses ranging from 874.3643 to 1587.8297. The stability of β-glucosidase depends on an initial concentration of 0.2 mg/mL of protein at pH 5.0 which decreases by 33% in a period of 30 h, and then stabilizes and is active for the next 5 days (pH 4.0 gives similar results). One hundred μg/mL β-D-glucose inhibited β-glucosidase activity by more than 50%. The enzyme had a K_m of 4.88 mM with p-NPG and a K_cat of 10,000 min⁻¹. The optimal conditions for the enzyme require a pH of 4.0 and a temperature of 50 °C. Full article

(This article belongs to the Section Natural Products Chemistry)

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11 pages, 296 KiB

Open AccessArticle

Design, Synthesis, Activity and Docking Study of Sorafenib Analogs Bearing Sulfonylurea Unit

by Chunjiang Wu¹, Min Wang¹, Qidong Tang¹, Rong Luo², Le Chen¹, Pengwu Zheng¹ and Wufu Zhu^1,*

¹ School of Pharmacy, Jiangxi Science & Technology Normal University, Nanchang 330013, China

² Jiangxi Province Institute of Materia Medica, Nanchang 330000, China

Molecules 2015, 20(10), 19361-19371; https://doi.org/10.3390/molecules201019361 - 23 Oct 2015

Cited by 41 | Viewed by 9388

Abstract

Two series of novel sorafenib analogs containing a sulfonylurea unit were synthesized and their chemical structures were confirmed by ¹H-NMR, ¹³C-NMR, MS spectrum and elemental analysis. The synthesized compounds were evaluated for the cytotoxicity against A549, Hela, MCF-7, and PC-3 [...] Read more.

Two series of novel sorafenib analogs containing a sulfonylurea unit were synthesized and their chemical structures were confirmed by ¹H-NMR, ¹³C-NMR, MS spectrum and elemental analysis. The synthesized compounds were evaluated for the cytotoxicity against A549, Hela, MCF-7, and PC-3 cancer cell lines. Some of the compounds showed moderate cytotoxic activity, especially compounds 1-(2,4-difluorophenylsulfonyl)-3-(4-(2-(methylcarbamoyl)pyridin-4-yloxy)phenyl)urea (6c) and 1-(4-bromophenylsulfonyl)-3-(4-(2-(methylcarbamoyl)pyridin-4-yloxy)phenyl)urea (6f) with the IC₅₀ values against four cancer cell lines ranging from 16.54 ± 1.22 to 63.92 ± 1.81 μM, respectively. Inhibitory rates against vascular endothelial growth factor receptor-2 (VEGFR2/KDR) kinase at 10 μM of target compounds were further carried out in this paper in order to investigate the target of these compounds. Structure-activity relationships (SARs) and docking studies indicated that the sulfonylurea unit was important to these kinds of compounds. None of the substitutions in the phenoxy group and small halogen atoms such as 2,4-difluoro substitution of the aryl group contributed to the activity. The results suggested that sulfonylurea sorafenib analogs are worthy of further study. Full article

(This article belongs to the Collection Efficient Pharmaceutical and Chemical Approaches for Anticancer Therapy: Design, Preliminary Evaluations, and Further Developments)

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18 pages, 1234 KiB

Open AccessArticle

Analysis of the Photophysical Behavior and Rotational-Relaxation Dynamics of Coumarin 6 in Nonionic Micellar Environments: The Effect of Temperature

by Cristóbal Carnero Ruiz^*,†, José Manuel Hierrezuelo^† and José Antonio Molina-Bolivar^†

¹ Department of Applied Physics II, Engineering School, University of Malaga, Malaga 29071, Spain

^† These authors contributed equally to this work.

Molecules 2015, 20(10), 19343-19360; https://doi.org/10.3390/molecules201019343 - 23 Oct 2015

Cited by 29 | Viewed by 7574

Abstract

The photodynamics of Coumarin 6 have been investigated in three nonionic micellar assemblies, i.e., n-dodecyl-β-d-maltoside (β-C₁₂G₂), p-tert-octyl-phenoxy polyethylene (9.5) ether (Triton X-100 or TX100) and n-dodecyl-hexaethylene-glycol (C₁₂E₆), to assess their potential [...] Read more.

The photodynamics of Coumarin 6 have been investigated in three nonionic micellar assemblies, i.e., n-dodecyl-β-d-maltoside (β-C₁₂G₂), p-tert-octyl-phenoxy polyethylene (9.5) ether (Triton X-100 or TX100) and n-dodecyl-hexaethylene-glycol (C₁₂E₆), to assess their potential use as encapsulation vehicles for hydrophobic drugs. To evaluate the effect of the micellar size and hydration, the study used a broad temperature range (293.15–323.15 K). The data presented here include steady-state absorption and emission spectra of the probe, dynamic light scattering, together with fluorescence lifetimes and both steady-state, as well as time-resolved fluorescence anisotropies. The time-resolved fluorescence anisotropy data were analyzed on the basis of the well-established two-step model. Our data reveal that the molecular probe in all of the cases is solubilized in the hydration layer of micelles, where it would sense a relatively polar environment. However, the probe was found to undergo a slower rotational reorientation when solubilized in the alkylpolyglycoside surfactant, as a result of a more compact microenvironment around the probe. The behavior of the parameters of the reorientation dynamics with temperature was analyzed on the basis of both micellar hydration and the head-group flexibility of the surfactants. Full article

(This article belongs to the Special Issue Coumarins, Xanthones and Related Compounds)

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13 pages, 1275 KiB

Open AccessArticle

Poly(Propylene Imine) Dendrimers and Amoxicillin as Dual-Action Antibacterial Agents

by Natalia Wrońska¹, Aleksandra Felczak¹, Katarzyna Zawadzka¹, Martyna Poszepczyńska¹, Sylwia Różalska¹, Maria Bryszewska², Dietmar Appelhans³

and Katarzyna Lisowska^1,*

¹ Department of Industrial Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, University of Lodz, 12/16 Banacha Street, 90-237 Lodz, Poland

² Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, 141/143, Pomorska Street, 90-236 Lodz, Poland

³ Leibniz Institute of Polymer Research Dresden, Hohe Street 6, 01069 Dresden, Germany

Molecules 2015, 20(10), 19330-19342; https://doi.org/10.3390/molecules201019330 - 23 Oct 2015

Cited by 23 | Viewed by 10862

Abstract

Besides acting as antimicrobial compounds, dendrimers can be considered as agents that improve the therapeutic effectiveness of existing antibiotics. In this work we present a new approach to using amoxicillin (AMX) against reference strains of common Gram-negative pathogens, alone and in combination with [...] Read more.

Besides acting as antimicrobial compounds, dendrimers can be considered as agents that improve the therapeutic effectiveness of existing antibiotics. In this work we present a new approach to using amoxicillin (AMX) against reference strains of common Gram-negative pathogens, alone and in combination with poly(propylene imine) (PPI) dendrimers, or derivatives thereof, in which 100% of the available hydrogen atoms are substituted with maltose (PPI 100%malG3). The concentrations of dendrimers used remained in the range non-toxic to eukaryotic cells. The results indicate that PPI dendrimers significantly enhance the antibacterial effect of amoxicillin alone, allowing antibiotic doses to be reduced. It is important to reduce doses of amoxicillin because its widespread use in medicine could lead to the development of bacterial resistance and environmental pollution. This is the first report on the combined antibacterial activity of PPI surface-modified maltose dendrimers and amoxicillin. Full article

(This article belongs to the Collection Nanomedicine)

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20 pages, 811 KiB

Open AccessArticle

A CuAAC–Hydrazone–CuAAC Trifunctional Scaffold for the Solid-Phase Synthesis of Trimodal Compounds: Possibilities and Limitations

by Benjamin Fabre, Jan Pícha, Václav Vaněk, Miloš Buděšínský and Jiří Jiráček^*

Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo n. 2, 16610 Praha 6, Czech Republic

Molecules 2015, 20(10), 19310-19329; https://doi.org/10.3390/molecules201019310 - 23 Oct 2015

Cited by 18 | Viewed by 7536

Abstract

We present a trifunctional scaffold designed for the solid-phase synthesis of trimodal compounds. This scaffold holds two alkyne arms in a free and TIPS-protected form for consecutive CuAAC (copper(I)-catalyzed azide–alkyne cycloaddition), one Fmoc-protected hydrazide arm for reaction with aldehydes, and one carboxylic acid [...] Read more.

We present a trifunctional scaffold designed for the solid-phase synthesis of trimodal compounds. This scaffold holds two alkyne arms in a free and TIPS-protected form for consecutive CuAAC (copper(I)-catalyzed azide–alkyne cycloaddition), one Fmoc-protected hydrazide arm for reaction with aldehydes, and one carboxylic acid arm with CF₂ groups for attachment to the resin and ¹⁹F-NMR quantification. This scaffold was attached to a resin and derivatized with model azides and aliphatic, electron-rich or electron-poor aromatic aldehydes. We identified several limitations of the scaffold caused by the instability of hydrazones in acidic conditions, in the presence of copper during CuAAC, and when copper accumulated in the resin. We successfully overcame these drawbacks by optimizing synthetic conditions for the derivatization of the scaffold with aromatic aldehydes. Overall, the new trifunctional scaffold combines CuAAC and hydrazone chemistries, offering a broader chemical space for the development of bioactive compounds. Full article

(This article belongs to the Section Organic Chemistry)

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19 pages, 3055 KiB

Open AccessArticle

Highly Selective Bioconversion of Ginsenoside Rb1 to Compound K by the Mycelium of Cordyceps sinensis under Optimized Conditions

by Wei-Nan Wang, Bing-Xiong Yan, Wen-Di Xu, Ye Qiu, Yun-Long Guo and Zhi-Dong Qiu^*

School of Pharmaceutical Sciences, Changchun University of Chinese Medicine, Changchun 130117, China

Molecules 2015, 20(10), 19291-19309; https://doi.org/10.3390/molecules201019291 - 23 Oct 2015

Cited by 22 | Viewed by 8375

Abstract

Compound K (CK), a highly active and bioavailable derivative obtained from protopanaxadiol ginsenosides, displays a wide variety of pharmacological properties, especially antitumor activity. However, the inadequacy of natural sources limits its application in the pharmaceutical industry. In this study, we firstly discovered that [...] Read more.

Compound K (CK), a highly active and bioavailable derivative obtained from protopanaxadiol ginsenosides, displays a wide variety of pharmacological properties, especially antitumor activity. However, the inadequacy of natural sources limits its application in the pharmaceutical industry. In this study, we firstly discovered that Cordyceps sinensis was a potent biocatalyst for the biotransformation of ginsenoside Rb1 into CK. After a series of investigations on the biotransformation parameters, an optimal composition of the biotransformation culture was found to be lactose, soybean powder and MgSO₄ without controlling the pH. Also, an optimum temperature of 30 °C for the biotransformation process was suggested in a range of 25 °C–50 °C. Then, a biotransformation pathway of Rb1 → Rd → F2 → CK was established using high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF-MS). Our results demonstrated that the molar bioconversion rate of Rb1 to CK was more than 82% and the purity of CK produced by C. sinensis under the optimized conditions was more than 91%. In conclusion, the combination of C. sinensis and the optimized conditions is applicable for the industrial preparation of CK for medicinal purposes. Full article

(This article belongs to the Section Natural Products Chemistry)

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14 pages, 3300 KiB

Open AccessArticle

Antimycobacterial Activities of Endolysins Derived From a Mycobacteriophage, BTCU-1

by Meng-Jiun Lai¹, Chih-Chin Liu², Shinn-Jong Jiang³, Po-Chi Soo¹, Meng-Hsuan Tu¹, Jen-Jyh Lee⁴, Ying-Huei Chen^4,5 and Kai-Chih Chang^1,5,*

¹ Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien 97004, Taiwan

² Department of Bioinformatics, Chung Hua University, Hsin-Chu City 97004, Taiwan

³ Department of Biochemistry, Tzu Chi University, Hualien 97004, Taiwan

⁴ Department of Internal Medicine, Buddhist Tzu Chi General Hospital, Hualien 97004, Taiwan

⁵ Department of Laboratory Medicine, Buddhist Tzu Chi General Hospital, Hualien 97004, Taiwan

Molecules 2015, 20(10), 19277-19290; https://doi.org/10.3390/molecules201019277 - 22 Oct 2015

Cited by 34 | Viewed by 7806

Abstract

The high incidence of Mycobacterium infection, notably multidrug-resistant M. tuberculosis infection, has become a significant public health concern worldwide. In this study, we isolate and analyze a mycobacteriophage, BTCU-1, and a foundational study was performed to evaluate the antimycobacterial activity of BTCU-1 and [...] Read more.

The high incidence of Mycobacterium infection, notably multidrug-resistant M. tuberculosis infection, has become a significant public health concern worldwide. In this study, we isolate and analyze a mycobacteriophage, BTCU-1, and a foundational study was performed to evaluate the antimycobacterial activity of BTCU-1 and its cloned lytic endolysins. Using Mycobacterium smegmatis as host, a mycobacteriophage, BTCU-1, was isolated from soil in eastern Taiwan. The electron microscopy images revealed that BTCU-1 displayed morphology resembling the Siphoviridae family. In the genome of BTCU-1, two putative lytic genes, BTCU-1_ORF7 and BTCU-1_ORF8 (termed lysA and lysB, respectively), were identified, and further subcloned and expressed in Escherichia coli. When applied exogenously, both LysA and LysB were active against M. smegmatis tested. Scanning electron microscopy revealed that LysA and LysB caused a remarkable modification of the cell shape of M. smegmatis. Intracellular bactericidal activity assay showed that treatment of M. smegmatis—infected RAW 264.7 macrophages with LysA or LysB resulted in a significant reduction in the number of viable intracellular bacilli. These results indicate that the endolysins derived from BTCU-1 have antimycobacterial activity, and suggest that they are good candidates for therapeutic/disinfectant agents to control mycobacterial infections. Full article

(This article belongs to the Collection Antibiotics & Superbugs: New Strategies to Combat Antimicrobial Resistance)

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14 pages, 310 KiB

Open AccessArticle

Novel 2-Thioxanthine and Dipyrimidopyridine Derivatives: Synthesis and Antimicrobial Activity

by Samar El-kalyoubi^1,*

, Fatmah Agili² and Shaker Youssif^3,4

¹ Organic Chemistry Department, Faculty of Pharmacy (Girls), ElAzhar University, Nasr City 11651, Egypt

² Chemistry Department, Faculty of Science, Jazan University, Jazan (Female Section) 45142, Saudi Arabia

³ Medical Chemistry Division, Faculty of Medicine, Jazan University, Jazan 82621, Saudi Arabia

⁴ Chemistry Department, Faculty of Science, Zagazig University, Zagazig 44511, Egypt

Molecules 2015, 20(10), 19263-19276; https://doi.org/10.3390/molecules201019263 - 22 Oct 2015

Cited by 11 | Viewed by 6232 | Correction

Abstract

Several fused imidazolopyrimidines were synthesized starting from 6-amino-1-methyl-2-thiouracil (1) followed by nitrosation, reduction and condensation with different aromatic aldehydes to give Schiff’s base. The dehydrocyclization of Schiff’s bases using iodine/DMF gave Compounds 5a–g. The methylation of 5a– [...] Read more.

Several fused imidazolopyrimidines were synthesized starting from 6-amino-1-methyl-2-thiouracil (1) followed by nitrosation, reduction and condensation with different aromatic aldehydes to give Schiff’s base. The dehydrocyclization of Schiff’s bases using iodine/DMF gave Compounds 5a–g. The methylation of 5a–g using a simple alkylating agent as dimethyl sulfate ((CH₃)₂SO₄) gave either monoalkylated imidazolopyrimidine 6a–g at room temperature or dialkylated derivatives 7a–g on heating 6a–g with ((CH₃)₂SO₄). On the other hand, treatment of 1 with different aromatic aldehydes in absolute ethanol in the presence of conc. hydrochloric acid at room temperature and/or reflux with acetic acid afforded bis-5,5́-diuracylmethylene 8a–e, which cyclized on heating with a mixture of acetic acid/HCl (1:1) to give 9a–e. Compounds 9a–e can be obtained directly by refluxing of Compound 1 with a mixture of acetic acid/HCl. The synthesized new compounds were screened for antimicrobial activity, and the MIC was measured. Full article

(This article belongs to the Collection Heterocyclic Compounds)

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11 pages, 837 KiB

Open AccessArticle

Cytotoxicity of Triterpenes from Green Walnut Husks of Juglans mandshurica Maxim in HepG-2 Cancer Cells

by Yuanyuan Zhou^1,†, Bingyou Yang^1,†, Zhaoxi Liu¹, Yanqiu Jiang¹, Yuxin Liu¹, Lei Fu¹, Xiaoli Wang² and Haixue Kuang^1,*

¹ College of Pharmacy, Heilongjiang University of Chinese Medicine, Harbin 150040, China

² College of Adult Education, Heilongjiang University of Chinese Medicine, Harbin 150040, China

^† These authors contributed equally to this work.

Molecules 2015, 20(10), 19252-19262; https://doi.org/10.3390/molecules201019252 - 22 Oct 2015

Cited by 29 | Viewed by 7151

Abstract

Among the classes of identified natural products, triterpenoids, one of the largest families, have been studied extensively for their diverse structures and variety of biological activities, including antitumor effects. In the present study, a phytochemical study of the green walnut husks of Juglans [...] Read more.

Among the classes of identified natural products, triterpenoids, one of the largest families, have been studied extensively for their diverse structures and variety of biological activities, including antitumor effects. In the present study, a phytochemical study of the green walnut husks of Juglans mandshurica Maxim led to the isolation of a new dammarane triterpene, 12β, 20(R), 24(R)-trihydroxydammar-25-en-3-one (6), together with sixteen known compounds, chiefly from chloroform and ethyl acetate extracts. According to their structural characteristics, these compounds were divided into dammarane-type, oleanane- and ursane-type. Dammarane-type triterpenoids were isolated for the first time from the Juglans genus. As part of our continuing search for biologically active compounds from this plant, all of these compounds were also evaluated for their cytotoxic activities against the growth of human cancer cells lines HepG-2 by the MTT assay. The results were shown that 20(S)-protopanaxadiol, 2α,3β,23-trihydroxyolean-12-en-28-oic acid and 2α,3β,23-trihydroxyurs-12-en-28-oic acid exhibited better cytotoxicity in vitro with IC₅₀ values of 10.32 ± 1.13, 16.13 ± 3.83, 15.97 ± 2.47 μM, respectively. Preliminary structure-activity relationships for these compounds were discussed. Full article

(This article belongs to the Collection Bioactive Compounds)

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16 pages, 1790 KiB

Open AccessArticle

A Self-Adaptive Steered Molecular Dynamics Method Based on Minimization of Stretching Force Reveals the Binding Affinity of Protein–Ligand Complexes

by Junfeng Gu^1,*, Hongxia Li² and Xicheng Wang¹

¹ State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian 116023, China

² School of Mechanical Engineering, Dalian University of Technology, Dalian 116023, China

Molecules 2015, 20(10), 19236-19251; https://doi.org/10.3390/molecules201019236 - 22 Oct 2015

Cited by 16 | Viewed by 7074

Abstract

Binding affinity prediction of protein–ligand complexes has attracted widespread interest. In this study, a self-adaptive steered molecular dynamics (SMD) method is proposed to reveal the binding affinity of protein–ligand complexes. The SMD method is executed through adjusting pulling direction to find an optimum [...] Read more.

Binding affinity prediction of protein–ligand complexes has attracted widespread interest. In this study, a self-adaptive steered molecular dynamics (SMD) method is proposed to reveal the binding affinity of protein–ligand complexes. The SMD method is executed through adjusting pulling direction to find an optimum trajectory of ligand dissociation, which is realized by minimizing the stretching force automatically. The SMD method is then used to simulate the dissociations of 19 common protein–ligand complexes which are derived from two homology families, and the binding free energy values are gained through experimental techniques. Results show that the proposed SMD method follows a different dissociation pathway with lower a rupture force and energy barrier when compared with the conventional SMD method, and further analysis indicates the rupture forces of the complexes in the same protein family correlate well with their binding free energy, which reveals the possibility of using the proposed SMD method to identify the active ligand. Full article

(This article belongs to the Section Medicinal Chemistry)

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15 pages, 2518 KiB

Open AccessArticle

γ-Alumina Nanoparticle Catalyzed Efficient Synthesis of Highly Substituted Imidazoles

by Bandapalli Palakshi Reddy¹, Vijayaparthasarathi Vijayakumar^1,*, Mariadhas Valan Arasu² and Naif Abdullah Al-Dhabi²

¹ Center for Organic and Medicinal Chemistry, VIT University, Vellore 632014, Tamil Nadu, India

² Department of Botany and Microbiology, Addiriyah Chair for Environmental Studies, College of Science, King Saud University, P. O. Box 2455, Riyadh 11451, Saudi Arabia

Molecules 2015, 20(10), 19221-19235; https://doi.org/10.3390/molecules201019221 - 21 Oct 2015

Cited by 13 | Viewed by 5823

Abstract

γ-Alumina nano particle catalyzed multi component reaction of benzil, arylaldehyde and aryl amines afforded the highly substituted 1,2,4,5-tetraaryl imidazoles with good to excellent yield in less reaction time under the sonication as well as the conventional methods. Convenient operational simplicity, mild conditions and [...] Read more.

γ-Alumina nano particle catalyzed multi component reaction of benzil, arylaldehyde and aryl amines afforded the highly substituted 1,2,4,5-tetraaryl imidazoles with good to excellent yield in less reaction time under the sonication as well as the conventional methods. Convenient operational simplicity, mild conditions and the reusability of catalyst were the other advantages of this developed protocol. Full article

(This article belongs to the Section Organic Chemistry)

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18 pages, 1083 KiB

Open AccessArticle

Greener Selective Cycloalkane Oxidations with Hydrogen Peroxide Catalyzed by Copper-5-(4-pyridyl)tetrazolate Metal-Organic Frameworks

by Luísa Martins^1,2,*

, Rajendar Nasani^3,†, Manideepa Saha^3,†, Shaikh Mobin^3,*,†, Suman Mukhopadhyay³ and Armando Pombeiro^2,*

¹ Chemical Engineering Departament, Instituto Superior de Engenharia de Lisboa, Instituto Politécnico de Lisboa, R. Conselheiro Emídio Navarro, 1959-007 Lisboa, Portugal

² Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal

³ Department of Chemistry, School of Basic Sciences, Indian Institute of Technology Indore, IET-DAVV Campus, Khandwa Road, Indore 452017, India

^† These authors contributed equally to this work.

Molecules 2015, 20(10), 19203-19220; https://doi.org/10.3390/molecules201019203 - 21 Oct 2015

Cited by 22 | Viewed by 7010

Abstract

Microwave assisted synthesis of the Cu(I) compound [Cu(µ₄-4-ptz)]_n [1, 4-ptz = 5-(4-pyridyl)tetrazolate]has been performed by employing a relatively easy method and within a shorter period of time compared to its sister compounds. The syntheses of the Cu(II) [...] Read more.

Microwave assisted synthesis of the Cu(I) compound [Cu(µ₄-4-ptz)]_n [1, 4-ptz = 5-(4-pyridyl)tetrazolate]has been performed by employing a relatively easy method and within a shorter period of time compared to its sister compounds. The syntheses of the Cu(II) compounds [Cu₃(µ₃-4-ptz)₄(µ₂-N₃)₂(DMF)₂]_n∙(DMF)_2n (2) and [Cu(µ₂-4-ptz)₂(H₂O)₂]_n (3) using a similar method were reported previously by us. MOFs 1-3 revealed high catalytic activity toward oxidation of cyclic alkanes (cyclopentane, -hexane and -octane) with aqueous hydrogen peroxide, under very mild conditions (at room temperature), without any added solvent or additive. The most efficient system (2/H₂O₂) showed, for the oxidation of cyclohexane, a turnover number (TON) of 396 (TOF of 40 h⁻¹), with an overall product yield (cyclohexanol and cyclohexanone) of 40% relative to the substrate. Moreover, the heterogeneous catalytic systems 1–3 allowed an easy catalyst recovery and reuse, at least for four consecutive cycles, maintaining ca. 90% of the initial high activity and concomitant high selectivity. Full article

(This article belongs to the Special Issue Metal Mediated Activation of Small Molecules)

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14 pages, 5398 KiB

Open AccessArticle

Enhanced Visible Light Photocatalytic Activity of Br-Doped Bismuth Oxide Formate Nanosheets

by Xin Feng¹, Wen Cui¹, Junbo Zhong², Xiaoying Liu³, Fan Dong^1,* and Yuxin Zhang^3,*

¹ Chongqing Key Laboratory of Catalysis and Functional Organic Molecules, College of Environment and Resources, Chongqing Technology and Business University, Chongqing 400067, China

² Key Laboratory of Green Catalysis of Sichuan Institutes of High Education, Sichuan University of Science and Technology, Zigong 643000, China

³ National Key Laboratory of Fundamental Science of Micro/Nano-Devices and System Technology, College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China

Molecules 2015, 20(10), 19189-19202; https://doi.org/10.3390/molecules201019189 - 21 Oct 2015

Cited by 14 | Viewed by 6831

Abstract

A facile method was developed to enhance the visible light photocatalytic activity of bismuth oxide formate (BiOCOOH) nanosheets via Br-doping. The as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, the Brunauer–Emmett–Teller surface area, UV-vis diffuse [...] Read more.

A facile method was developed to enhance the visible light photocatalytic activity of bismuth oxide formate (BiOCOOH) nanosheets via Br-doping. The as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, the Brunauer–Emmett–Teller surface area, UV-vis diffuse reflectance spectroscopy, photoluminescence spectra, and N₂ adsorption-desorption isotherms measurement. The Br⁻ ions replaced the COOH⁻ ions in the layers of BiOCOOH, result in a decreased layer distance. The photocatalytic activity of the as-prepared materials was evaluated by removal of NO in qir at ppb level. The results showed that the Br-doped BiOCOOH nanosheets showed enhanced visible light photocatalytic activtiy with a NO removal of 37.8%. The enhanced activity can be ascribed to the increased visible light absorption and the promoted charge separation. Full article

(This article belongs to the Special Issue Nano-Structural Photocatalytic Materials: Synthesis, Characterization and Applications)

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17 pages, 1232 KiB

Open AccessArticle

Iridoids and Flavonoids of Four Siberian Gentians: Chemical Profile and Gastric Stimulatory Effect

by Daniil N. Olennikov^1,*

, Nina I. Kashchenko¹, Nadezhda K. Chirikova² and Larisa M. Tankhaeva¹

¹ Institute of General and Experimental Biology, Siberian Division, Russian Academy of Science, Sakh’yanovoy Str., 6, Ulan-Ude 670047, Russia

² Department of Biochemistry and Biotechnology, North-Eastern Federal University, 58 Belinsky Str., Yakutsk 677027, Russia

Molecules 2015, 20(10), 19172-19188; https://doi.org/10.3390/molecules201019172 - 21 Oct 2015

Cited by 46 | Viewed by 8022

Abstract

Some Gentiana species have been used by the nomadic people of Siberia as bitter teas or appetizers to eliminate digestive disorders (dyspepsia, heartburn, nausea, etc.). We studied the most frequently used gentians: Gentiana algida, G. decumbens, G. macrophylla and G. triflora [...] Read more.

Some Gentiana species have been used by the nomadic people of Siberia as bitter teas or appetizers to eliminate digestive disorders (dyspepsia, heartburn, nausea, etc.). We studied the most frequently used gentians: Gentiana algida, G. decumbens, G. macrophylla and G. triflora. The aim of the present study was to evaluate the phytochemical features and gastrostimulatnt activity of these four gentian herbs. Five iridoids, seven flavones and mangiferin were detected in gentian herbs after analysis by microcolumn-RP-HPLC-UV-ESI-MS. A componential phytochemical profile of the G. decumbens herb is presented for the first time, as well as information about distinct phytochemicals found in gentian herbs. HPLC quantification of the specific compounds of gentian herbs demonstrated the high content of iridoids (24.73–73.53 mg/g) and flavonoids (12.92–78.14 mg/g). The results of biological activity evaluation of four gentian decoctions demonstrated their good ability to stimulate acid-, enzyme- and mucin-forming functions of the stomach attributed to mostly by iridoids and flavonoids. In general, it can be claimed that the gentian decoctions can be used as effective and safe appetizers and are also a good source of biologically active agents. Full article

(This article belongs to the Collection Herbal Medicine Research)

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30 pages, 860 KiB

Open AccessReview

Six-Membered Aromatic Polyazides: Synthesis and Application

by Sergei V. Chapyshev

Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka 142432, Moscow Region, Russian

Molecules 2015, 20(10), 19142-19171; https://doi.org/10.3390/molecules201019142 - 21 Oct 2015

Cited by 27 | Viewed by 10563

Abstract

Aromatic polyazides are widely used as starting materials in organic synthesis and photochemical studies, as well as photoresists in microelectronics and as cross-linking agents in polymer chemistry. Some aromatic polyazides possess high antitumor activity, while many others are of considerable interest as high-energy [...] Read more.

Aromatic polyazides are widely used as starting materials in organic synthesis and photochemical studies, as well as photoresists in microelectronics and as cross-linking agents in polymer chemistry. Some aromatic polyazides possess high antitumor activity, while many others are of considerable interest as high-energy materials and precursors of high-spin nitrenes and C₃N₄ carbon nitride nanomaterials. The use of aromatic polyazides in click-reactions may be a new promising direction in the design of various supramolecular systems possessing interesting chemical, physical and biological properties. This review is devoted to the synthesis, properties and applications of six-membered aromatic compounds containing three and more azido groups in the ring. Full article

(This article belongs to the Special Issue Organic Azides)

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12 pages, 1640 KiB

Open AccessArticle

Olefin Metathesis Reaction in Water and in Air Improved by Supramolecular Additives

by Jasmine Tomasek¹, Miriam Seßler¹, Harald Gröger²

and Jürgen Schatz^1,*

¹ Organic Chemistry 1, Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Henkestraße 42, D-91054 Erlangen, Germany

² Faculty of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany

Molecules 2015, 20(10), 19130-19141; https://doi.org/10.3390/molecules201019130 - 21 Oct 2015

Cited by 12 | Viewed by 6679

Abstract

A range of water-immiscible commercially available Grubbs-type precatalysts can be used in ring-closing olefin metathesis reaction in high yields. The synthetic transformation is possible in pure water under ambient conditions. Sulfocalixarenes can help to boost the reactivity of the metathesis reaction by [...] Read more.

A range of water-immiscible commercially available Grubbs-type precatalysts can be used in ring-closing olefin metathesis reaction in high yields. The synthetic transformation is possible in pure water under ambient conditions. Sulfocalixarenes can help to boost the reactivity of the metathesis reaction by catalyst activation, improved mass transfer, and solubility of reactants in the aqueous reaction media. Additionally, the use of supramolecular additives allows lower catalyst loadings, but still high activity in pure water under aerobic conditions. Full article

(This article belongs to the Special Issue Olefin Metathesis)

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29 pages, 1304 KiB

Open AccessArticle

Synthesis, Molecular Structure, Metabolic Stability and QSAR Studies of a Novel Series of Anticancer N-Acylbenzenesulfonamides

by Beata Żołnowska¹, Jarosław Sławiński^1,*

, Mariusz Belka², Tomasz Bączek², Anna Kawiak^3,4, Jarosław Chojnacki⁵

, Aneta Pogorzelska¹ and Krzysztof Szafrański¹

¹ Department of Organic Chemistry, Medical University of Gdańsk, Al. Gen. J. Hallera 107, 80-416 Gdańsk, Poland

² Department of Pharmaceutical Chemistry, Medical University of Gdańsk, Al. Gen. J. Hallera 107, 80-416 Gdańsk, Poland

³ Department of Biotechnology, Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, ul. Kładki 24, 80-822 Gdańsk, Poland

⁴ Department of Human Physiology, Medical University of Gdańsk, ul. Tuwima 15, 80-210 Gdańsk, Poland

⁵ Department of Inorganic Chemistry, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland

Molecules 2015, 20(10), 19101-19129; https://doi.org/10.3390/molecules201019101 - 21 Oct 2015

Cited by 15 | Viewed by 6323

Abstract

A series of novel N-acyl-4-chloro-5-methyl-2-(R¹-methylthio)benzenesulfonamides 18–47 have been synthesized by the reaction of N-[4-chloro-5-methyl-2-(R¹-methylthio) benzenesulfonyl]cyanamide potassium salts with appropriate carboxylic acids. Some of them showed anticancer activity toward the human cancer cell lines MCF-7, HCT-116 [...] Read more.

A series of novel N-acyl-4-chloro-5-methyl-2-(R¹-methylthio)benzenesulfonamides 18–47 have been synthesized by the reaction of N-[4-chloro-5-methyl-2-(R¹-methylthio) benzenesulfonyl]cyanamide potassium salts with appropriate carboxylic acids. Some of them showed anticancer activity toward the human cancer cell lines MCF-7, HCT-116 and HeLa, with the growth percentages (GPs) in the range from 7% to 46%. Quantitative structure-activity relationship (QSAR) studies on the cytotoxic activity of N-acylsulfonamides toward MCF-7, HCT-116 and HeLa were performed by using topological, ring and charge descriptors based on the stepwise multiple linear regression technique (MLR). The QSAR studies revealed three predictive and statistically significant models for the investigated compounds. The results obtained with these models indicated that the anticancer activity of N-acylsulfonamides depends on topological distances, number of ring system, maximum positive charge and number of atom-centered fragments. The metabolic stability of the selected compounds had been evaluated on pooled human liver microsomes and NADPH, both R¹ and R² substituents of the N-acylsulfonamides simultaneously affected them. Full article

(This article belongs to the Section Medicinal Chemistry)

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Molecules, Volume 20, Issue 10 (October 2015) – 108 articles , Pages 17684-19646

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