Molecules

590 KiB

Open AccessArticle

Diorganotin(IV) Derivatives of N-Methyl p-Fluorobenzo-Hydroxamic Acid: Preparation, Spectral Characterization, X-ray Diffraction Studies and Antitumor Activity

by Naqeebullah, Yang Farina, Kok Meng Chan, Lo Kong Mun, Nor Fadilah Rajab and Theng Choon Ooi

Molecules 2013, 18(7), 8696-8711; https://doi.org/10.3390/molecules18078696 - 22 Jul 2013

Cited by 27 | Viewed by 6654

Abstract

Three diorganotin(IV) complexes of the general formula R₂Sn[RcC(O)N(RN)O] (Rc = aryl, RN = Alkyl) have been synthesized by refluxing in toluene the corresponding diorganotin(IV) oxides with the free ligand N-methyl p-fluorobenzohydroxamic acid, [...] Read more.

Three diorganotin(IV) complexes of the general formula R₂Sn[RcC(O)N(RN)O] (Rc = aryl, RN = Alkyl) have been synthesized by refluxing in toluene the corresponding diorganotin(IV) oxides with the free ligand N-methyl p-fluorobenzohydroxamic acid, using a Dean and Stark water separator. The ligand was derived from the reaction of the corresponding p-fluorobenzoyl chloride and N-methylhydroxylamine hydrochloride in the presence of sodium hydrogen carbonate. The isolated free ligand and its respective diorganotin compounds have been characterized by elemental analysis, IR and ¹H-, ¹³C-, ¹¹⁹Sn-NMR spectroscopies. The crystal structures of the diorganotin complexes have been confirmed by single crystal X-ray diffraction methods. The investigations carried out on the diorganotin(IV) complexes of N-methyl p-fluorobenzohydroxamic acid confirmed a 1:2 stoichiometry. The complex formation took place through the O,O-coordination via the carbonyl oxygen and subsequent deprotonated hydroxyl group to the tin atom. The crystal structures of three diorganotin complexes were determined and were found to adopt six coordination geometries at the tin centre with coordination to two ligand moieties. Full article

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Open AccessArticle

MYB Transcription Factors Regulate Glucosinolate Biosynthesis in Different Organs of Chinese Cabbage (Brassica rapa ssp. pekinensis)

by Yeon Bok Kim, Xiaohua Li, Sun-Ju Kim, Haeng Hoon Kim, Jeongyeo Lee, HyeRan Kim and Sang Un Park

Molecules 2013, 18(7), 8682-8695; https://doi.org/10.3390/molecules18078682 - 22 Jul 2013

Cited by 69 | Viewed by 9264

Abstract

In this study, we investigated the expression of seven MYB transcription factors (a total of 17 genes that included Dof1.1, IQD1-1, MYB28, MYB29, MYB34, MYB51, and MYB122 and their isoforms) involved in aliphatic and indolic glucosinolate (GSL) biosynthesis and analyzed the aliphatic and [...] Read more.

In this study, we investigated the expression of seven MYB transcription factors (a total of 17 genes that included Dof1.1, IQD1-1, MYB28, MYB29, MYB34, MYB51, and MYB122 and their isoforms) involved in aliphatic and indolic glucosinolate (GSL) biosynthesis and analyzed the aliphatic and indolic GSL content in different organs of Chinese cabbage (Brassica rapassp. Pekinensis). MYB28 and MYB29 expression in the stem was dramatically different when compared with the levels in the other organs. MYB34, MYB122, MYB51, Dof1.1, and IQD1-1 showed very low transcript levels among different organs. HPLC analysis showed that the glucosinolates (GSLs) consisted of five aliphatic GSLs (progoitrin, sinigrin, glucoalyssin, gluconapin, and glucobrassicanapin) and four indolic GSLs (4-hydroxyglucobrassicin, glucobrassicin, 4-methoxygluco-brassicin, and neoglucobrassicin). Aliphatic GSLs exhibited 63.3% of the total GSLs content, followed by aromatic GSL (19.0%), indolic GSLs (10%), and unknown GSLs (7.7%) in different organs of Chinese cabbage. The total GSL content of different parts (ranked in descending order) was as follows: seed > flower > young leaves > stem > root > old leaves. The relationship between GSLs accumulation and expression of GSLs biosynthesis MYB TFs genes in different organs may be helpful to understand the mechanism of MYB TFs regulating GSL biosynthesis in Chinese cabbage. Full article

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704 KiB

Open AccessArticle

Phenolic Content and Antioxidant Activities of Burr Parsley (Caucalis platycarpos L.)

by Ana Plazonić, Ana Mornar, Željan Maleš and Nikola Kujundžić

Molecules 2013, 18(7), 8666-8681; https://doi.org/10.3390/molecules18078666 - 22 Jul 2013

Cited by 7 | Viewed by 7572

Abstract

Since C. platycarpos contains a wide variety of antioxidants, in the present study total flavonoid and phenolic acid content as well as antioxidative activity of various C. platycarpos extracts were investigated. The results obtained show a significant polyphenol content and antioxidant activity of [...] Read more.

Since C. platycarpos contains a wide variety of antioxidants, in the present study total flavonoid and phenolic acid content as well as antioxidative activity of various C. platycarpos extracts were investigated. The results obtained show a significant polyphenol content and antioxidant activity of the investigated plant. Moreover, a positive correlation between antioxidant activity and content of flavonoids and phenolic acids was found, indicating the responsibility of these compounds for the antioxidant effectiveness of C. platycarpos extracts and making C. platycarpos a good potential source of natural antioxidants. Full article

(This article belongs to the Section Natural Products Chemistry)

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866 KiB

Open AccessReview

Recent Trends in Bioorthogonal Click-Radiolabeling Reactions Using Fluorine-18

by Marc Pretze, Doreen Pietzsch and Constantin Mamat

Molecules 2013, 18(7), 8618-8665; https://doi.org/10.3390/molecules18078618 - 22 Jul 2013

Cited by 75 | Viewed by 13039

Abstract

The increasing application of positron emission tomography (PET) in nuclear medicine has stimulated the extensive development of a multitude of novel and versatile bioorthogonal conjugation techniques especially for the radiolabeling of biologically active high molecular weight compounds like peptides, proteins or antibodies. Taking [...] Read more.

The increasing application of positron emission tomography (PET) in nuclear medicine has stimulated the extensive development of a multitude of novel and versatile bioorthogonal conjugation techniques especially for the radiolabeling of biologically active high molecular weight compounds like peptides, proteins or antibodies. Taking into consideration that the introduction of fluorine-18 (t_1/2 = 109.8 min) proceeds under harsh conditions, radiolabeling of these biologically active molecules represents an outstanding challenge and is of enormous interest. Special attention has to be paid to the method of ¹⁸F-introduction. It should proceed in a regioselective manner under mild physiological conditions, in an acceptable time span, with high yields and high specific activities. For these reasons and due to the high number of functional groups found in these compounds, a specific labeling procedure has to be developed for every bioactive macromolecule. Bioorthogonal strategies including the Cu-assisted Huisgen cycloaddition and its copper-free click variant, both Staudinger Ligations or the tetrazine-click reaction have been successfully applied and represent valuable alternatives for the selective introduction of fluorine-18 to overcome the afore mentioned obstacles. This comprehensive review deals with the progress and illustrates the latest developments in the field of bioorthogonal labeling with the focus on the preparation of radiofluorinated building blocks and tracers for molecular imaging. Full article

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

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Open AccessArticle

The Effect of PAMAM Dendrimers on the Antibacterial Activity of Antibiotics with Different Water Solubility

by Katarzyna Winnicka, Magdalena Wroblewska, Piotr Wieczorek, Pawel Tomasz Sacha and Elzbieta Anna Tryniszewska

Molecules 2013, 18(7), 8607-8617; https://doi.org/10.3390/molecules18078607 - 22 Jul 2013

Cited by 59 | Viewed by 7245

Abstract

Erythromycin (EM) and tobramycin (TOB) are well-known and widely used antibiotics, belonging to different therapeutic groups: macrolide and aminoglycoside, respectively. Moreover, they possess different solubility: EM is slightly soluble and TOB is freely soluble in water. It was previously demonstrated that PAMAM dendrimers [...] Read more.

Erythromycin (EM) and tobramycin (TOB) are well-known and widely used antibiotics, belonging to different therapeutic groups: macrolide and aminoglycoside, respectively. Moreover, they possess different solubility: EM is slightly soluble and TOB is freely soluble in water. It was previously demonstrated that PAMAM dendrimers enhanced the pharmacological activity of antifungal drugs by increasing their solubility. Therefore, it appears interesting to investigate the effect of PAMAM-NH₂ and PAMAM-OH dendrimers generation 2 (G2) and generation 3 (G3) on the antibacterial activity of antibiotics with different water solubility. In this study it was shown that the aqueous solubility of EM was significantly increased by PAMAM dendrimers (PAMAM-NH₂ and PAMAM-OH caused about 8- and 7- fold solubility increases, respectively). However, it was indicated that despite the increase in the solubility, there was only slight influence on the antibacterial activity of EM (2- and 4- fold decreases in the MBC values of EM in the presence of PAMAM-OH G3 and PAMAM-NH₂ G2 or G3 for strains of Staphylococcus aureus were noted, respectively). It was also found that there was no influence of PAMAM on the antibacterial activity of hydrophilic TOB. Full article

(This article belongs to the Special Issue Dendrimers in Medicine and Biotechnology)

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Open AccessArticle

Searching for Stable Si_nC_n Clusters: Combination of Stochastic Potential Surface Search and Pseudopotential Plane-Wave Car-Parinello Simulated Annealing Simulations

by Xiaofeng F. Duan, Larry W. Burggraf and Lingyu Huang

Molecules 2013, 18(7), 8591-8606; https://doi.org/10.3390/molecules18078591 - 22 Jul 2013

Cited by 16 | Viewed by 5816

Abstract

To find low energy Si_nC_n structures out of hundreds to thousands of isomers we have developed a general method to search for stable isomeric structures that combines Stochastic Potential Surface Search and Pseudopotential Plane-Wave Density Functional Theory Car-Parinello Molecular Dynamics [...] Read more.

To find low energy Si_nC_n structures out of hundreds to thousands of isomers we have developed a general method to search for stable isomeric structures that combines Stochastic Potential Surface Search and Pseudopotential Plane-Wave Density Functional Theory Car-Parinello Molecular Dynamics simulated annealing (PSPW-CPMD-SA). We enhanced the Sunders stochastic search method to generate random cluster structures used as seed structures for PSPW-CPMD-SA simulations. This method ensures that each SA simulation samples a different potential surface region to find the regional minimum structure. By iterations of this automated, parallel process on a high performance computer we located hundreds to more than a thousand stable isomers for each Si_nC_n cluster. Among these, five to 10 of the lowest energy isomers were further optimized using B3LYP/cc-pVTZ method. We applied this method to Si_nC_n (n = 4–12) clusters and found the lowest energy structures, most not previously reported. By analyzing the bonding patterns of low energy structures of each Si_nC_n cluster, we observed that carbon segregations tend to form condensed conjugated rings while Si connects to unsaturated bonds at the periphery of the carbon segregation as single atoms or clusters when n is small and when n is large a silicon network spans over the carbon segregation region. Full article

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Open AccessArticle

Structure of the C-terminal Region of the Frizzled Receptor 1 in Detergent Micelles

by Shovanlal Gayen, Qingxin Li, Young Mee Kim and CongBao Kang

Molecules 2013, 18(7), 8579-8590; https://doi.org/10.3390/molecules18078579 - 22 Jul 2013

Cited by 13 | Viewed by 6694

Abstract

The C-terminal domains of the Frizzleds (FZDs) contain a short conserved motif (KTXXXW). It has been demonstrated that FZDs interacted with the PDZ domain of the cytoplasmic proteins such as Dishevelled through this motif and mutations in this motif disrupted Wnt/β-catenin signaling. We [...] Read more.

The C-terminal domains of the Frizzleds (FZDs) contain a short conserved motif (KTXXXW). It has been demonstrated that FZDs interacted with the PDZ domain of the cytoplasmic proteins such as Dishevelled through this motif and mutations in this motif disrupted Wnt/β-catenin signaling. We carried out structural studies for a peptide derived from the C-terminal domain of the FZD₁ in different solvents using circular dichroism and solution NMR spectroscopy. Our results showed that this domain was unstructured in an aqueous solution and formed a helical structure in detergent micelles. Fluorescence studies suggested that the tryptophan residue (W630) in the motif interacted with micelles. The solution structure of the peptide in sodium dodecyl sulfate micelles was determined and an amphipathic helix was identified. This helix may have similar function to the helix 8 of other G protein-coupled receptors. Full article

(This article belongs to the Special Issue NMR of Proteins and Small Biomolecules)

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Open AccessArticle

Elaboration of Stable and Antibody Functionalized Positively Charged Colloids by Polyelectrolyte Complexation between Chitosan and Hyaluronic Acid

by Ramona C. Polexe and Thierry Delair

Molecules 2013, 18(7), 8563-8578; https://doi.org/10.3390/molecules18078563 - 19 Jul 2013

Cited by 56 | Viewed by 7699

Abstract

In this study, we describe the elaboration of multifunctional positively charged polyelectrolyte complex (PEC) nanoparticles, designed to be stable at physiological salt concentration and pH, for effective targeted delivery. These nanoparticles were obtained by charge neutralization between chitosan (CS) as polycation and hyaluronic [...] Read more.

In this study, we describe the elaboration of multifunctional positively charged polyelectrolyte complex (PEC) nanoparticles, designed to be stable at physiological salt concentration and pH, for effective targeted delivery. These nanoparticles were obtained by charge neutralization between chitosan (CS) as polycation and hyaluronic acid (HA) as polyanion. We showed that the course of the complexation process and the physico-chemical properties of the resulting colloids were impacted by (i) internal parameters such as the Degree of Acetylation (DA, i.e., the molar ration of acetyl glucosamine residues) and molar mass of CS, the HA molar mass and (ii) external parameters like the charge mixing ratio and the polymer concentrations. As a result, nonstoichiometric colloidal PECs were obtained in water or PBS (pH 7.4) and remained stable over one month. The polymer interactions were characterized by thermal analysis (DSC and TGA) and the morphology was studied by scanning electron microscopy. A model antibody, anti-ovalbumine (OVA) immunoglobulin A (IgA) was sorbed on the particle surface in water and PBS quantitatively in 4 h. The CS-HA/IgA nanoparticles average size was between 425–665 nm with a positive zeta potential. These results pointed out that CS-HA can be effective carriers for use in targeted drug delivery. Full article

(This article belongs to the Special Issue Chitins and Chitosans)

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294 KiB

Open AccessArticle

Synthesis and Bioassay of a New Class of Furanyl-1,3,4-Oxadiazole Derivatives

by Mohamed M. El Sadek, Seham Y. Hassan, Huda E. Abdelwahab and Galila A. Yacout

Molecules 2013, 18(7), 8550-8562; https://doi.org/10.3390/molecules18078550 - 19 Jul 2013

Cited by 14 | Viewed by 5663

Abstract

Tyrosinase enzyme is a monophenol monoxygenase enzyme, which plays an important role in human as a rate limiting step enzyme for different specific metabolic pathways, as well as its useful application in industry and agriculture. So this study was carried out to test [...] Read more.

Tyrosinase enzyme is a monophenol monoxygenase enzyme, which plays an important role in human as a rate limiting step enzyme for different specific metabolic pathways, as well as its useful application in industry and agriculture. So this study was carried out to test the effect of newly prepared compounds containing 1,3,4-oxadiazoles with different substituted groups on tyrosinase enzyme activity, hoping to use them in the treatment of some diseases arising from tyrosinase activity disorders such as Parkinson’s disease, schizophrenia, autism, attention deficit, hyperactivity disorder, and cancer. Full article

(This article belongs to the Section Organic Chemistry)

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494 KiB

Open AccessArticle

Synthesis and Biological Evaluation of a New Acyclic Pyrimidine Derivative as a Probe for Imaging Herpes Simplex Virus Type 1 Thymidine Kinase Gene Expression

by Andrijana Meščić, Thomas Betzel, Adrienne Müller, Roger Slavik, Stjepko Čermak, Silvana Raić-Malić and Simon M. Ametamey

Molecules 2013, 18(7), 8535-8549; https://doi.org/10.3390/molecules18078535 - 19 Jul 2013

Cited by 1 | Viewed by 6283

Abstract

With the idea of finding a more selective radiotracer for imaging herpes simplex virus type 1 thymidine kinase (HSV1-tk) gene expression by means of positron emission tomography (PET), a novel [¹⁸F]fluorine radiolabeled pyrimidine with 4-hydroxy-3-(hydroxymethyl)butyl side chain at N-1 (HHB-5-[ [...] Read more.

With the idea of finding a more selective radiotracer for imaging herpes simplex virus type 1 thymidine kinase (HSV1-tk) gene expression by means of positron emission tomography (PET), a novel [¹⁸F]fluorine radiolabeled pyrimidine with 4-hydroxy-3-(hydroxymethyl)butyl side chain at N-1 (HHB-5-[¹⁸F]FEP) was prepared and evaluated as a potential PET probe. Unlabeled reference compound, HHB-5-FEP, was synthesized via a five-step reaction sequence starting from 5-(2-acetoxyethyl)-4-methoxypyrimidin-2-one. The radiosynthesis of HHB-[¹⁸F]-FEP was accomplished by nucleophilic radiofluorination of a tosylate precursor using [¹⁸F]fluoride-cryptate complex in 45% ± 4 (n = 4) radiochemical yields and high purity (>99%). The biological evaluation indicated the feasibility of using HHB-5-[¹⁸F]FEP as a PET radiotracer for monitoring HSV1-tk expression in vivo. Full article

(This article belongs to the Special Issue Synthesis of Nucleosides, Nucleotides and Their Derivatives)

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Open AccessArticle

A Straightforward Diphenylmethyl Protection Method and Deprotection of Some Pyrimidine Nucleosides

by Milind Saudi and Arthur Van Aerschot

Molecules 2013, 18(7), 8524-8534; https://doi.org/10.3390/molecules18078524 - 18 Jul 2013

Cited by 11 | Viewed by 7412

Abstract

Benzhydryl protection of primary and secondary alcohols has been reported previously via reaction with metal alcoholates. Our aim was to find generally useful and very mild conditions for the alcoholic protection and deprotection of nucleosides with the diphenylmethyl group. This was accomplished for [...] Read more.

Benzhydryl protection of primary and secondary alcohols has been reported previously via reaction with metal alcoholates. Our aim was to find generally useful and very mild conditions for the alcoholic protection and deprotection of nucleosides with the diphenylmethyl group. This was accomplished for some pyrimidine nucleosides using PdCl₂ as the transition metal catalyst, and with optimization yields of 70–90% have been achieved. A lack of solubility of other nucleosides hampers its more general use. Full article

(This article belongs to the Special Issue Synthesis of Nucleosides, Nucleotides and Their Derivatives)

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Open AccessArticle

Two New Chiratane-Type Triterpenoids from Swertia kouitchensis

by Luo-Sheng Wan, Ting-Ting Liu, Xiao-Jun Lin, Qiu-Xia Min and Jia-Chun Chen

Molecules 2013, 18(7), 8518-8523; https://doi.org/10.3390/molecules18078518 - 18 Jul 2013

Cited by 9 | Viewed by 5503

Abstract

Two rare new chiratane-type triterpenoids, kouitchenoids A and B (1, 2), together with oleanolic acid (3) and ursolic acid (4), were isolated from ethanol extract of Swertia kouitchensis. The new structures were determined by the [...] Read more.

Two rare new chiratane-type triterpenoids, kouitchenoids A and B (1, 2), together with oleanolic acid (3) and ursolic acid (4), were isolated from ethanol extract of Swertia kouitchensis. The new structures were determined by the analysis of MS and NMR data. In addition, compounds 1–4 showed moderate inhibitory activity against the α-glucosidase (with IC₅₀ values ranging from 1,812 to 2,027 μM). Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessArticle

Decomposition Mechanisms and Kinetics of Novel Energetic Molecules BNFF-1 and ANFF-1: Quantum-Chemical Modeling

by Roman V. Tsyshevsky and Maija M. Kuklja

Molecules 2013, 18(7), 8500-8517; https://doi.org/10.3390/molecules18078500 - 18 Jul 2013

Cited by 39 | Viewed by 6718

Abstract

Decomposition mechanisms, activation barriers, Arrhenius parameters, and reaction kinetics of the novel explosive compounds, 3,4-bis(4-nitro-1,2,5-oxadiazol-3-yl)-1,2,5-oxadiazole (BNFF-1), and 3-(4-amino-1,2,5-oxadiazol-3-yl)-4-(4-nitro-1,2,5-oxadiazol-3-yl)-1,2,5-oxadiazole (ANFF-1) were explored by means of density functional theory with a range of functionals combined with variational transition state theory. BNFF-1 and ANFF-1 were recently [...] Read more.

Decomposition mechanisms, activation barriers, Arrhenius parameters, and reaction kinetics of the novel explosive compounds, 3,4-bis(4-nitro-1,2,5-oxadiazol-3-yl)-1,2,5-oxadiazole (BNFF-1), and 3-(4-amino-1,2,5-oxadiazol-3-yl)-4-(4-nitro-1,2,5-oxadiazol-3-yl)-1,2,5-oxadiazole (ANFF-1) were explored by means of density functional theory with a range of functionals combined with variational transition state theory. BNFF-1 and ANFF-1 were recently suggested to be good candidates for insensitive high energy density materials. Our modeling reveals that the decomposition initiation in both BNFF-1 and ANFF-1 molecules is triggered by ring cleavage reactions while the further process is defined by a competition between two major pathways, the fast C-NO₂ homolysis and slow nitro-nitrite isomerization releasing NO. We discuss insights on design of new energetic materials with targeted properties gained from our modeling. Full article

(This article belongs to the Special Issue Computational Chemistry)

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194 KiB

Open AccessArticle

Preliminary Phytochemical Screening and Antibacterial Properties of Crude Stem Bark Extracts and Fractions of Parkia biglobosa (Jacq.)

by Emmanuel O. Abioye, David A. Akinpelu, Olayinka A. Aiyegoro, Mobolaji F. Adegboye, Matthew O. Oni and Anthony I. Okoh

Molecules 2013, 18(7), 8485-8499; https://doi.org/10.3390/molecules18078485 - 18 Jul 2013

Cited by 38 | Viewed by 8986

Abstract

A methanolic crude extract of Parkia biglobosa was prepared and later partitioned in succession with different solvents of increasing polarity ranging from n-hexane, chloroform and ethyl acetate to butanol. Phytochemical screening of the extract revealed the presence of alkaloids, tannins, saponins, flavonoids, [...] Read more.

A methanolic crude extract of Parkia biglobosa was prepared and later partitioned in succession with different solvents of increasing polarity ranging from n-hexane, chloroform and ethyl acetate to butanol. Phytochemical screening of the extract revealed the presence of alkaloids, tannins, saponins, flavonoids, steroids, glycoside and sugars. The inhibition zones exhibited by the extract against the tested bacteria ranged between 14 ± 0.00 mm (against Escherichia coli) and 28 ± 0.71 mm (against Pseudomonas aeruginosa). The MIC of the methanolic extract of P. biglobosa against isolates ranged between 0.63 mg/mL and 5 mg/mL, while the MIC values exhibited by the n-hexane and aqueous fractions ranged between 0.63 mg/mL and 10 mg/mL. Overall the extract and fractions of P. biglobosa used in this work were found to possess antimicrobial properties which compared favourably with those of streptomycin. These observations make this plant a potential source of bioactive compounds that can be used in management of bacterial infections. The use of this plant as herbal medicaments in African countries and the reports on the toxicity of the plant further show that the plant is non-toxic to humans. Full article

(This article belongs to the Section Natural Products Chemistry)

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550 KiB

Open AccessArticle

Hydrophosphonylation of Nanoparticle Schiff Bases as a Mean for Preparation of Aminophosphonate-Functionalized Nanoparticles

by Justyna Siemieniec, Pawel Kafarski and Pawel Plucinski

Molecules 2013, 18(7), 8473-8484; https://doi.org/10.3390/molecules18078473 - 18 Jul 2013

Cited by 9 | Viewed by 5945

Abstract

The development of nanotechnology is responsible for an increase in the achievements in medical diagnostics and in the preparation of new therapeutic vehicles. In particular, magnetic nanoparticles with a modified surface are a very attractive alternative to deliver therapeutic agents. We describe the [...] Read more.

The development of nanotechnology is responsible for an increase in the achievements in medical diagnostics and in the preparation of new therapeutic vehicles. In particular, magnetic nanoparticles with a modified surface are a very attractive alternative to deliver therapeutic agents. We describe the modification of the surface of the iron oxide nanoparticles with aminophosphonic acids by applying the classic hydrophosphonylation approach. Full article

(This article belongs to the Special Issue Organophosphorus Chemistry)

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Open AccessArticle

Preparation and Characterization of Poly(ethyl hydrazide)-Grafted Oil Palm Empty Fruit Bunch Fibre for the Removal of Cu(II) Ions from an Aqueous Environment

by Ili Syazana Johari, Nor Azah Yusof, Md Jelas Haron and Siti Mariam Mohd Nor

Molecules 2013, 18(7), 8461-8472; https://doi.org/10.3390/molecules18078461 - 18 Jul 2013

Cited by 11 | Viewed by 5086

Abstract

Poly(ethyl hydrazide)-grafted oil palm empty fruit bunch fibre (peh-g-opefb) was successfully prepared by heating poly(methyl acrylate)-grafted opefb (pma-g-opefb) at 60 °C for 4 h with a solution of hydrazine hydrate (15% v/v) in ethanol. The Fourier transform infrared spectrum of the product shows [...] Read more.

Poly(ethyl hydrazide)-grafted oil palm empty fruit bunch fibre (peh-g-opefb) was successfully prepared by heating poly(methyl acrylate)-grafted opefb (pma-g-opefb) at 60 °C for 4 h with a solution of hydrazine hydrate (15% v/v) in ethanol. The Fourier transform infrared spectrum of the product shows a secondary amine peak at 3267 cm⁻¹, with amide carbonyl peaks at 1729 cm⁻¹ and 1643 cm⁻¹. The chelating ability of peh-g-opefb was tested with copper ion in aqueous solution. A batch adsorption study revealed that maximum adsorption of copper ion was achieved at pH 5. An isotherm study showed the adsorption follows a Langmuir model, with a maximum adsorption capacity of 43.48 mg g⁻¹ at 25 °C. A kinetic study showed that the adsorption of copper ion rapidly reaches equilibrium and follows a pseudo–second-order kinetic model, with a constant rate of 7.02 × 10⁻⁴ g mg⁻¹ min⁻¹ at 25 °C. The Gibbs free energy, ∆G⁰, value is negative, indicating a spontaneous sorption process. Entropy, ∆S⁰, gives a positive value, indicating that the system is becoming increasingly disordered after the adsorption of copper ion. A positive enthalpy value, ∆H⁰, shows that the endothermic process takes place during the adsorption and is more favourable at high temperatures. Full article

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Open AccessReview

Dendrimers in Layer-by-Layer Assemblies: Synthesis and Applications

by Katsuhiko Sato and Jun-ichi Anzai

Molecules 2013, 18(7), 8440-8460; https://doi.org/10.3390/molecules18078440 - 17 Jul 2013

Cited by 66 | Viewed by 10653

Abstract

We review the synthesis of dendrimer-containing layer-by-layer (LbL) assemblies and their applications, including biosensing, controlled drug release, and bio-imaging. Dendrimers can be built into LbL films and microcapsules by alternating deposition of dendrimers and counter polymers on the surface of flat substrates and [...] Read more.

We review the synthesis of dendrimer-containing layer-by-layer (LbL) assemblies and their applications, including biosensing, controlled drug release, and bio-imaging. Dendrimers can be built into LbL films and microcapsules by alternating deposition of dendrimers and counter polymers on the surface of flat substrates and colloidal microparticles through electrostatic bonding, hydrogen bonding, covalent bonding, and biological affinity. Dendrimer-containing LbL assemblies have been used to construct biosensors, in which electron transfer mediators and metal nanoparticles are often coupled with dendrimers. Enzymes have been successfully immobilized on the surface of electrochemical and optical transducers by forming enzyme/dendrimer LbL multilayers. In this way, high-performance enzyme sensors are fabricated. In addition, dendrimer LbL films and microcapsules are useful for constructing drug delivery systems because dendrimers bind drugs to form inclusion complexes or the dendrimer surface is covalently modified with drugs. Magnetic resonance imaging of cancer cells by iron oxide nanoparticles coated with dendrimer LbL film is also discussed. Full article

(This article belongs to the Special Issue Dendrimers in Medicine and Biotechnology)

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Open AccessArticle

Separation and Identification of 1,2,4-Trihydroxynaphthalene-1-O-glucoside in Impatiens glandulifera Royle

by Jan Tříska, Naděžda Vrchotová, Jan Sýkora and Martin Moos

Molecules 2013, 18(7), 8429-8439; https://doi.org/10.3390/molecules18078429 - 17 Jul 2013

Cited by 18 | Viewed by 6764

Abstract

Methanolic extract from lyophilized roots of Impatiens glandulifera Royle was analyzed by high performance liquid chromatography using DAD and FLD detection and this revealed one dominant highly fluorescent very unstable substance. The stability of this derivative is strongly dependent on the plant material [...] Read more.

Methanolic extract from lyophilized roots of Impatiens glandulifera Royle was analyzed by high performance liquid chromatography using DAD and FLD detection and this revealed one dominant highly fluorescent very unstable substance. The stability of this derivative is strongly dependent on the plant material drying procedure and extraction procedure used. The structure of the substance was established as 1,2,4-trihydroxynaphthalene-1-O-glucoside (THNG) according LC-MS and NMR measurements. When lyophilized plant material was extracted with methanol an almost four times higher amount of THNG was found in the extract, compared to the amount of 2-hydroxy-1,4-naphthoquinone obtained, while in the case of the same lyophilized plant material extracted with water there was no THNG in the extract. The main compounds in this case was 2-hydroxy-1,4-naphthoquinone. In the plant material dried at the laboratory temperature and extracted by methanol there are only traces of THNG. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessCommunication

Characterization of Water Extractable Arabinoxylans from a Spring Wheat Flour: Rheological Properties and Microstructure

by Adriana Morales-Ortega, Elizabeth Carvajal-Millan, Yolanda López-Franco, Agustín Rascón-Chu, Jaime Lizardi-Mendoza, Patricia Torres-Chavez and Alma Campa-Mada

Molecules 2013, 18(7), 8417-8428; https://doi.org/10.3390/molecules18078417 - 16 Jul 2013

Cited by 46 | Viewed by 8139

Abstract

In the present study water extractable arabinoxylans (WEAX) from a Mexican spring wheat flour (cv. Tacupeto F2001) were isolated, characterized and gelled and the gel rheological properties and microstructure were investigated. These WEAX presented an arabinose to xylose ratio of 0.66, a ferulic [...] Read more.

In the present study water extractable arabinoxylans (WEAX) from a Mexican spring wheat flour (cv. Tacupeto F2001) were isolated, characterized and gelled and the gel rheological properties and microstructure were investigated. These WEAX presented an arabinose to xylose ratio of 0.66, a ferulic acid and diferulic acid content of 0.526 and 0.036 µg/mg WEAX, respectively and a Fourier Transform Infra-Red (FT-IR) spectrum typical of arabinoxylans. The intrinsic viscosity and viscosimetric molecular weight values for WEAX were 3.5 dL/g and 504 kDa, respectively. WEAX solution at 2% (w/v) formed gels induced by a laccase as cross-linking agent. Cured WEAX gels registered storage (G’) and loss (G’’) modulus values of 31 and 5 Pa, respectively and a diferulic acid content of 0.12 µg/mg WEAX, only traces of triferulic acid were detected. Scanning electron microscopy analysis of the lyophilized WEAX gels showed that this material resembles that of an imperfect honeycomb. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessArticle

Characterization of Flavonoids and Phenolic Acids in Myrcia bella Cambess. Using FIA-ESI-IT-MSⁿ and HPLC-PAD-ESI-IT-MS Combined with NMR

by Luiz L. Saldanha, Wagner Vilegas and Anne L. Dokkedal

Molecules 2013, 18(7), 8402-8416; https://doi.org/10.3390/molecules18078402 - 16 Jul 2013

Cited by 158 | Viewed by 11639

Abstract

The leaves of Myrcia DC. ex Guill species are used in traditional medicine and are also exploited commercially as herbal drugs for the treatment of diabetes mellitus. The present work aimed to assess the qualitative and quantitative profiles of M. bella hydroalcoholic extract, [...] Read more.

The leaves of Myrcia DC. ex Guill species are used in traditional medicine and are also exploited commercially as herbal drugs for the treatment of diabetes mellitus. The present work aimed to assess the qualitative and quantitative profiles of M. bella hydroalcoholic extract, due to these uses, since the existing legislation in Brazil determines that a standard method must be developed in order to be used for quality control of raw plant materials. The current study identified eleven known flavonoid-O-glycosides and six acylated flavonoid derivatives of myricetin and quercetin, together with two kaempferol glycosides and phenolic acids such as caffeic acid, ethil galate, gallic acid and quinic acid. In total, 24 constituents were characterized, by means of extensive preparative chromatographic analyses, along with MS and NMR techniques. An HPLC-PAD-ESI-IT-MS and FIA-ESI-IT-MSⁿ method were developed for rapid identification of acylated flavonoids, flavonoid-O-glycosides derivatives of myricetin and quercetin and phenolic acids in the hydroalcoholic M. bella leaves extract. The FIA-ESI-IT-MS techinique is a powerful tool for direct and rapid identification of the constituents after isolation and NMR characterization. Thus, it could be used as an initial method for identification of authentic samples concerning quality control of Myrcia spp extracts. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessArticle

Distinct Metabolites for Photoreactive l-Phenylalanine Derivatives in Klebsiella sp. CK6 Isolated from Rhizosphere of a Wild Dipterocarp Sapling

by Lei Wang, Wataru Hisano, Yuta Murai, Munenori Sakurai, Yasuyuki Muto, Haruka Ikemoto, Masashi Okamoto, Takashi Murotani, Reika Isoda, Dongyeop Kim, Yasuko Sakihama, Irnayuli R. Sitepu, Yasuyuki Hashidoko, Yasumaru Hatanaka and Makoto Hashimoto

Molecules 2013, 18(7), 8393-8401; https://doi.org/10.3390/molecules18078393 - 16 Jul 2013

Cited by 10 | Viewed by 10428

Abstract

Photoaffinity labeling is a reliable analytical method for biological functional analysis. Three major photophores—aryl azide, benzophenone and trifluoromethyldiazirine—are utilized in analysis. Photophore-bearing l-phenylalanine derivatives, which are used for biological functional analysis, were inoculated into a Klebsiella sp. isolated from the rhizosphere of a [...] Read more.

Photoaffinity labeling is a reliable analytical method for biological functional analysis. Three major photophores—aryl azide, benzophenone and trifluoromethyldiazirine—are utilized in analysis. Photophore-bearing l-phenylalanine derivatives, which are used for biological functional analysis, were inoculated into a Klebsiella sp. isolated from the rhizosphere of a wild dipterocarp sapling in Central Kalimantan, Indonesia, under nitrogen-limiting conditions. The proportions of metabolites were quite distinct for each photophore. These results indicated that photophores affected substrate recognition in rhizobacterial metabolic pathways, and differential photoaffinity labeling could be achieved using different photophore-containing l-phenylalanine derivatives. Full article

(This article belongs to the Special Issue Reagents and Methods for Protein Target Identification)

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Open AccessArticle

Development of 65 Novel Polymorphic cDNA-SSR Markers in Common Vetch (Vicia sativa subsp. sativa) Using Next Generation Sequencing

by Jong-Wook Chung, Tae-Sung Kim, Sundan Suresh, Sok-Young Lee and Gyu-Taek Cho

Molecules 2013, 18(7), 8376-8392; https://doi.org/10.3390/molecules18078376 - 16 Jul 2013

Cited by 42 | Viewed by 6542

Abstract

Vetch (Vicia sativa L.) is one of the most important annual forage legumes in the World due to its multiple uses (i.e., hay, grain, silage and green manure) and high nutritional value. However, detrimental cyanoalanine toxins in its plant parts [...] Read more.

Vetch (Vicia sativa L.) is one of the most important annual forage legumes in the World due to its multiple uses (i.e., hay, grain, silage and green manure) and high nutritional value. However, detrimental cyanoalanine toxins in its plant parts including seeds and its vulnerability to hard winter conditions are currently reducing the agronomic values of vetch varieties. Moreover, the existence in the public domain of very few genomic resources, especially molecular markers, has further hampered breeding efforts. Polymorphic simple sequence repeat markers from transcript sequences (cDNA; simple sequence repeat [SSR]) were developed for Vicia sativa subsp. sativa. We found 3,811 SSR loci from 31,504 individual sequence reads, and 300 primer pairs were designed and synthesized. In total, 65 primer pairs were found to be consistently scorable when 32 accessions were tested. The numbers of alleles ranged from 2 to 19, frequency of major alleles per locus were 0.27–0.87, the genotype number was 2–19, the overall polymorphism information content (PIC) values were 0.20–0.86, and the observed and expected heterozygosity values were 0.00–0.41 and 0.264–0.852, respectively. These markers provide a useful tool for assessing genetic diversity, population structure, and positional cloning, facilitating vetch breeding programs. Full article

(This article belongs to the Section Molecular Diversity)

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Open AccessArticle

Thermal Behavior of Pinan-2-ol and Linalool

by Janne Leiner, Achim Stolle, Bernd Ondruschka, Thomas Netscher and Werner Bonrath

Molecules 2013, 18(7), 8358-8375; https://doi.org/10.3390/molecules18078358 - 16 Jul 2013

Cited by 6 | Viewed by 7291

Abstract

Linalool is an important intermediate for syntheses of isoprenoid fragrance compounds and vitamins A and E. One process option for its production is the thermal gas-phase isomerization of cis- and trans-pinan-2-ol. Investigations of this reaction were performed in a flow-type apparatus [...] Read more.

Linalool is an important intermediate for syntheses of isoprenoid fragrance compounds and vitamins A and E. One process option for its production is the thermal gas-phase isomerization of cis- and trans-pinan-2-ol. Investigations of this reaction were performed in a flow-type apparatus in a temperature range from 350–600 °C and a residence time range of 0.6–0.8 s. Rearrangement of the bicyclic alcohol led to linalool, plinols arising from consecutive reactions of linalool and other side products. Effects of residence time, temperature, surface-to-volume-ratio, carrier gas, and the presence of additives on yield and selectivity were studied. Furthermore, the effects of such parameters on ene-cyclization of linalool affording plinols were investigated. Results indicate that manipulation of the reaction in order to affect selectivity is difficult due to the large free path length to other molecules in the gas phase. However, conditions have been identified allowing one to increase the selectivity and the yield of linalool throughout pyrolysis of pinan-2-ol. Full article

(This article belongs to the Special Issue Gas Phase Reactions)

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HPLC Analysis of Phenolics Compounds and Antioxidant Capacity of Leaves of Vitex megapotamica (Sprengel) Moldenke

by Thiele Faccim De Brum, Marina Zadra, Mariana Piana, Aline Augusti Boligon, Janaina Kieling Fröhlich, Robson Borba De Freitas, Sílvio Terra Stefanello, Amanda Luana Forbrig Froeder, Bianca Vargas Belke, Letícia Teixeira Nunes, Roberta Da Silva Jesus, Michel Mansur Machado, João Batista Teixeira da Rocha, Félix Alexandre Antunes Soares and Margareth Linde Athayde

Molecules 2013, 18(7), 8342-8357; https://doi.org/10.3390/molecules18078342 - 16 Jul 2013

Cited by 31 | Viewed by 7656

Abstract

Vitex megapotamica (Sprengel) Moldenke belongs to the Verbenaceae family and is popularly known as “tarumã”. The antioxidant capacity of fractions and crude extract from the leaves of V. megapotamica were determined in this study through the capacity to remove reactive species and phenolic [...] Read more.

Vitex megapotamica (Sprengel) Moldenke belongs to the Verbenaceae family and is popularly known as “tarumã”. The antioxidant capacity of fractions and crude extract from the leaves of V. megapotamica were determined in this study through the capacity to remove reactive species and phenolic compounds were quantified in the various fractions. The IC₅₀ (DPPH) ranged from 14.17 ± 0.76 to 37.63 ± 0.98 µg/mL. The ethyl acetate fraction might contain the strongest lipid peroxidation inhibitory compounds with an IC₅₀ of 16.36 ± 5.09 µg/mL, being also the one with the highest content of polyphenols (522.4 ± 1.12 mg/g), flavonoids (220.48 ± 0.30 mg/g) and condensed tannins (3.86 ± 0.53 mg/g). Compounds quantified by HPLC/DAD in the crude extract and fractions were chlorogenic and rosmarinic acids. Higher dosages of the extracts were more effective in reducing levels of plasma protein carbonyls and were also shown to be able to remove reactive species by a 2',7'-dichlorofluorescein diacetate assay, reducing oxidative stress in all tested fractions. Results obtained indicated that V. megapotamica exhibits good potential to prevent diseases caused by the overproduction of free radicals and it might also be used as a potential source of natural antioxidant agents. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessArticle

Factors Influencing the Antifolate Activity of Synthetic Tea-Derived Catechins

by Magalí Sáez-Ayala, María Piedad Fernández-Pérez, Soledad Chazarra, Nani Mchedlishvili, Alberto Tárraga-Tomás and José Neptuno Rodríguez-López

Molecules 2013, 18(7), 8319-8341; https://doi.org/10.3390/molecules18078319 - 16 Jul 2013

Cited by 6 | Viewed by 6736

Abstract

Novel tea catechin derivatives have been synthesized, and a structure-activity study, related to the capacity of these and other polyphenols to bind dihydrofolate reductase (DHFR), has been performed. The data showed an effective binding between all molecules and the free enzyme, and the [...] Read more.

Novel tea catechin derivatives have been synthesized, and a structure-activity study, related to the capacity of these and other polyphenols to bind dihydrofolate reductase (DHFR), has been performed. The data showed an effective binding between all molecules and the free enzyme, and the dissociation constants of the synthetic compounds and of the natural analogues were on the same order. Polyphenols with a catechin configuration were better DHFR inhibitors than those with an epicatechin configuration. Antiproliferative activity was also studied in cultured tumour cells, and the data showed that the activity of the novel derivatives was higher in catechin isomers. Derivatives with a hydroxyl group para on the ester-bonded gallate moiety presented a high in vitro binding to DHFR, but exhibited transport problems in cell culture due to ionization at physiologic pHs. The impact of the binding of catechins to serum albumin on their biological activity was also evaluated. The information provided in this study could be important for the design of novel medicinal active compounds derived from tea catechins. The data suggest that changes in their structure to avoid serum albumin interactions and to facilitate plasmatic membrane transport are essential for the intracellular functions of catechins. Full article

(This article belongs to the Special Issue Structure-Activity Relationship of Flavonoids)

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Open AccessReview

The Genus Gnaphalium L. (Compositae): Phytochemical and Pharmacological Characteristics

by Xing Zheng, Wei Wang, Huishan Piao, Weiqiang Xu, Haibo Shi and Chengai Zhao

Molecules 2013, 18(7), 8298-8318; https://doi.org/10.3390/molecules18078298 - 15 Jul 2013

Cited by 39 | Viewed by 8752

Abstract

The genus Gnaphalium, a herb distributed worldwide, comprises approximately 200 species of the Compositae (Asteraceae) family that belongs to the tribe Gnaphalieae. Some species are traditionally used as wild vegetables and in folk medicine. This review focuses on the phytochemical investigations and [...] Read more.

The genus Gnaphalium, a herb distributed worldwide, comprises approximately 200 species of the Compositae (Asteraceae) family that belongs to the tribe Gnaphalieae. Some species are traditionally used as wild vegetables and in folk medicine. This review focuses on the phytochemical investigations and biological studies of plants from the genus Gnaphalium over the past few decades. More than 125 chemical constituents have been isolated from the genus Gnaphalium, including flavonoids, sesquiterpenes, diterpenes, triterpenes, phytosterols, anthraquinones, caffeoylquinic acid derivatives, and other compounds. The extracts of this genus, as well as compounds isolated from it, have been demonstrated to possess multiple pharmacological activities such as antioxidant, antibacterial and antifungal, anti-complement, antitussive and expectorant, insect antifeedant, cytotoxic, anti-inflammatory, antidiabetic and antihypouricemic properties. The present review compiles the information available on this genus because of its relevance to food and ethnopharmacology and the potential therapeutic uses of these species. Full article

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Open AccessArticle

Enhanced Stability of CaO and/or La₂O₃ Promoted Pd/Al₂O₃ Egg-Shell Catalysts in Partial Oxidation of Methane to Syngas

by Jinlong Wang, Hongbo Yu, Zhen Ma and Shenghu Zhou

Molecules 2013, 18(7), 8289-8297; https://doi.org/10.3390/molecules18078289 - 15 Jul 2013

Cited by 9 | Viewed by 6334

Abstract

An egg-shell Pd/Al₂O₃ catalyst showed higher activity than a regular Pd/Al₂O₃ catalyst in the partial oxidation of methane to syngas, but a common problem of this reaction is the catalyst deactivation on stream. We attempted to modify [...] Read more.

An egg-shell Pd/Al₂O₃ catalyst showed higher activity than a regular Pd/Al₂O₃ catalyst in the partial oxidation of methane to syngas, but a common problem of this reaction is the catalyst deactivation on stream. We attempted to modify the egg-shell catalyst via impregnation with some metal oxide additives. Although the addition of MgO did not show any beneficial effect, the addition of CaO and/or La₂O₃ significantly improved the stability due to the suppression of carbon deposition and phase transformation of the Al₂O₃ support. The catalysts were characterized by X-ray diffraction (XRD), N₂ adsorption-desorption, and thermogravimetric analysis (TGA). Full article

(This article belongs to the Special Issue Palladium Catalysts)

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Differential Growth Inhibitory Effects of Highly Oxygenated Guaianolides Isolated from the Middle Eastern Indigenous Plant Achillea falcata in HCT-116 Colorectal Cancer Cells

by Rita Tohme, Lamis Al Aaraj, Tarek Ghaddar, Hala Gali-Muhtasib, Najat A. Saliba and Nadine Darwiche

Molecules 2013, 18(7), 8275-8288; https://doi.org/10.3390/molecules18078275 - 15 Jul 2013

Cited by 16 | Viewed by 7018

Abstract

Medicinal plants play a crucial role in traditional medicine and in the maintenance of human health worldwide. Sesquiterpene lactones represent an interesting group of plant-derived compounds that are currently being tested as lead drugs in cancer clinical trials. Achillea falcata is a medicinal [...] Read more.

Medicinal plants play a crucial role in traditional medicine and in the maintenance of human health worldwide. Sesquiterpene lactones represent an interesting group of plant-derived compounds that are currently being tested as lead drugs in cancer clinical trials. Achillea falcata is a medicinal plant indigenous to the Middle Eastern region and belongs to the Asteraceae family, which is known to be rich in sesquiterpene lactones. We subjected Achillea falcata extracts to bioassay-guided fractionation against the growth of HCT-116 colorectal cancer cells and identified four secotanapartholides, namely 3-β-methoxy- isosecotanapartholide (1), isosecotanapartholide (2), tanaphallin (3), and 8-hydroxy-3-methoxyisosecotanapartholide (4). Three highly oxygenated guaianolides were isolated for the first time from Achillea falcata, namely rupin A (5), chrysartemin B (6), and 1β, 2β-epoxy- 3β,4α,10α-trihydroxyguaian- 6α,12-olide (7). These sesquiterpene lactones showed no or minor cytotoxicity while exhibiting promising anticancer effects against HCT-116 cells. Further structure-activity relationship studies related the bioactivity of the tested compounds to their skeleton, their lipophilicity, and to the type of functional groups neighboring the main alkylating center of the molecule. Full article

(This article belongs to the Special Issue Bioassay-Guided Isolation of Natural Products)

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Open AccessArticle

Morphology and Metal Binding Characteristics of a Natural Polymer—Kondagogu (Cochlospermum gossypium) Gum

by V. T. P. Vinod, R. B. Sashidhar and Miroslav Černík

Molecules 2013, 18(7), 8264-8274; https://doi.org/10.3390/molecules18078264 - 15 Jul 2013

Cited by 17 | Viewed by 8346

Abstract

Kondagogu (Cochlospermum gossypium) gum (KG), a natural tree exudate, was investigated for its morphological, adsorption and metal interaction behavior with various toxic heavy metals (Pb, Cd, Ni, Cr and Fe). SEM, AFM and TEM techniques were used to study the morphological [...] Read more.

Kondagogu (Cochlospermum gossypium) gum (KG), a natural tree exudate, was investigated for its morphological, adsorption and metal interaction behavior with various toxic heavy metals (Pb, Cd, Ni, Cr and Fe). SEM, AFM and TEM techniques were used to study the morphological changes occurring after metal adsorption onto the biopolymer structure. The degree of biosorption of metals on KG biopolymer surfaces was assessed by small-angle X-ray scattering analysis. EDXA spectrum revealed that the ion-exchange mechanism plays a major role in the binding process between KG and metal ions. The higher electron density observed in the KG-Cd complex suggests that Cd is strongly bound to KG compared to the other metals. This work provides a potential platform for developing a hydrocolloid-based nanogel for bioremediation of environmental contaminants. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessReview

The Pharmacological Activities of (−)-Anonaine

by Hsing-Tan Li, Hui-Ming Wu, Hsin-Liang Chen, Chi-Ming Liu and Chung-Yi Chen

Molecules 2013, 18(7), 8257-8263; https://doi.org/10.3390/molecules18078257 - 12 Jul 2013

Cited by 38 | Viewed by 9092

Abstract

Several species of Magnoliaceae and Annonaceae are used in Traditional Chinese Medicine. (−)-Anonaine, isolated from several species of Magnoliaceae and Annonaceae, presents antiplasmodial, antibacterial, antifungal, antioxidation, anticancer, antidepression, and vasorelaxant activity. This article provides an overview of the pharmacological functions of (−)-anonaine. Full article

(This article belongs to the Special Issue Alkaloids: Novel Therapeutic Perspectives)

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Molecules, Volume 18, Issue 7 (July 2013) – 88 articles , Pages 7336-8711

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