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2013 Volume 24 Issue 11
2013, 24(11): 949-952
Abstract:
A twin-axial hetero[5]pseudorotaxane was constructed based on 1-hexyl-4,40-bipyridinium guest 1 and cucurbit[8]uril (CB[8]) and a-cyclodextrin (a-CD). In its structure, CB[8] included two bipyridinium units to realize the twin-axial mode, and the hexyl chain was threaded into the cavity of a-CD. The [5]pseudorotaxane contains two types of macrocyclic hosts while the single axial and twin axial modes co-exist in its structure. The transformation of [5]pseudorotaxane could be realized by the addition of acid and 2,6-dihydroxynaphthalene (HN).
A twin-axial hetero[5]pseudorotaxane was constructed based on 1-hexyl-4,40-bipyridinium guest 1 and cucurbit[8]uril (CB[8]) and a-cyclodextrin (a-CD). In its structure, CB[8] included two bipyridinium units to realize the twin-axial mode, and the hexyl chain was threaded into the cavity of a-CD. The [5]pseudorotaxane contains two types of macrocyclic hosts while the single axial and twin axial modes co-exist in its structure. The transformation of [5]pseudorotaxane could be realized by the addition of acid and 2,6-dihydroxynaphthalene (HN).
2013, 24(11): 953-956
Abstract:
An efficient formal synthesis of (+)-tashiromine was achieved by employing an intermolecular asymmetric Mannich-type reaction as the key step. Concurrently, a novel approach toward the total synthesis of (+)-stemoamide through dyotropic rearrangement of 3,4-cis-β-lactone was also explored.
An efficient formal synthesis of (+)-tashiromine was achieved by employing an intermolecular asymmetric Mannich-type reaction as the key step. Concurrently, a novel approach toward the total synthesis of (+)-stemoamide through dyotropic rearrangement of 3,4-cis-β-lactone was also explored.
2013, 24(11): 957-961
Abstract:
Straightforward and direct synthesis of 2-substituted-5-oxazolecarbaldehydes was achieved by treating propargylamides with mercury(Ⅱ) perchlorate as catalyst and ammonium cerium(Ⅳ) nitrate as oxidant agent through intramolecular cyclization. These structurally interesting outcomes benefit to synthesize 2,5-disubstituted-1,3-oxazoles with armyworm growth regulating activities.
Straightforward and direct synthesis of 2-substituted-5-oxazolecarbaldehydes was achieved by treating propargylamides with mercury(Ⅱ) perchlorate as catalyst and ammonium cerium(Ⅳ) nitrate as oxidant agent through intramolecular cyclization. These structurally interesting outcomes benefit to synthesize 2,5-disubstituted-1,3-oxazoles with armyworm growth regulating activities.
2013, 24(11): 962-966
Abstract:
Two new compounds (1 and 2) based on indole were successfully synthesized and characterized. They display highly selective response to F- in aqueous DMSO medium and pure DMSO with remarkable color and fluorescent changes. Therefore, both receptors may serve as colorimetric sensors for F- by visual detection.
Two new compounds (1 and 2) based on indole were successfully synthesized and characterized. They display highly selective response to F- in aqueous DMSO medium and pure DMSO with remarkable color and fluorescent changes. Therefore, both receptors may serve as colorimetric sensors for F- by visual detection.
2013, 24(11): 967-969
Abstract:
The 1,2,3-thiadiazole-carboxylate moiety was reported to be an important pharmacophore of plant activators. In this study, a series of novel plant activators based on thieno[2,3-d]-1,2,3-thiadiazole-6-carboxylate were designed and synthesized and their biological activity as plant activators was studied. The structures of the novel compounds were identified by 1H NMR, 19F NMR and HRMS. The in vivo bioassay showed that these novel compounds had good efficacy against seven plant diseases. Especially, compounds 1a and 1c were more potent than the commercialized plant activator BTH. Almost no fungicidal activity was observed for the active compounds in the in vivo assay, which matched the requirements as plant activators.
The 1,2,3-thiadiazole-carboxylate moiety was reported to be an important pharmacophore of plant activators. In this study, a series of novel plant activators based on thieno[2,3-d]-1,2,3-thiadiazole-6-carboxylate were designed and synthesized and their biological activity as plant activators was studied. The structures of the novel compounds were identified by 1H NMR, 19F NMR and HRMS. The in vivo bioassay showed that these novel compounds had good efficacy against seven plant diseases. Especially, compounds 1a and 1c were more potent than the commercialized plant activator BTH. Almost no fungicidal activity was observed for the active compounds in the in vivo assay, which matched the requirements as plant activators.
2013, 24(11): 970-974
Abstract:
Polymeric nanoparticles (NPs) have drawn great interest in the past few years due to their potential applications in the fields of biomedical and optical technologies. However, it is still a challenge to prepare functional polymeric NPs, especially for particle diameters smaller than 50 nm. In this work, we demonstrate a one-pot method to fabricate reactive poly(divinyl benzene-co-maleic anhydride) NPs (PDVBMAH NPs) through a self-stable precipitation polymerization process. The size and morphology of these PDVBMAH NPs were characterized in detail by scanning electronic microscopy, and their chemical structure was determined by IR. The results showed that these NPs were highly cross-linked and their diameter was about 30 nm with narrow distribution. Additionally, the DVB and MAH endow the NPs with reactive surface anhydride and pendant vinyl groups, and these particles could be further functionalized through reaction of these groups. A plausible pathway was proposed for the formation of PDVBMAH NPs.
Polymeric nanoparticles (NPs) have drawn great interest in the past few years due to their potential applications in the fields of biomedical and optical technologies. However, it is still a challenge to prepare functional polymeric NPs, especially for particle diameters smaller than 50 nm. In this work, we demonstrate a one-pot method to fabricate reactive poly(divinyl benzene-co-maleic anhydride) NPs (PDVBMAH NPs) through a self-stable precipitation polymerization process. The size and morphology of these PDVBMAH NPs were characterized in detail by scanning electronic microscopy, and their chemical structure was determined by IR. The results showed that these NPs were highly cross-linked and their diameter was about 30 nm with narrow distribution. Additionally, the DVB and MAH endow the NPs with reactive surface anhydride and pendant vinyl groups, and these particles could be further functionalized through reaction of these groups. A plausible pathway was proposed for the formation of PDVBMAH NPs.
2013, 24(11): 975-978
Abstract:
A kind of octanol-modifided silica nanoparticle was fabricated and employed as a framework to form "soggy sand" electrolyte along with 1-butyl-3-methylimidazolium tetrafluoroborate. "Soggy sand" and poly(vinylidene fluoride-hexafluoropropylene) composite electrolyte membranes were electrospun for the first time. The properties of this membrane electrolyte have been evaluated by the mechanical test and electrochemical test. The Young's modulus increased by 275% from 6.8 MPa to 25.5 MPa and the electrical conductivity increased to 7.6×10-5S/cm at 290.15 K when compared to pristine P(VdF-HFP) membrane electrolyte. The conductivity is 3.1×10-4S/cm at 323.15 K.
A kind of octanol-modifided silica nanoparticle was fabricated and employed as a framework to form "soggy sand" electrolyte along with 1-butyl-3-methylimidazolium tetrafluoroborate. "Soggy sand" and poly(vinylidene fluoride-hexafluoropropylene) composite electrolyte membranes were electrospun for the first time. The properties of this membrane electrolyte have been evaluated by the mechanical test and electrochemical test. The Young's modulus increased by 275% from 6.8 MPa to 25.5 MPa and the electrical conductivity increased to 7.6×10-5S/cm at 290.15 K when compared to pristine P(VdF-HFP) membrane electrolyte. The conductivity is 3.1×10-4S/cm at 323.15 K.
2013, 24(11): 979-983
Abstract:
An expedient, synthetic method to fused polycyclic derivatives of isoquinoline is described via tandem reaction of isoquinoline, dialkyl acetylenedicarboxylates and dialkyl chloromalonate.
An expedient, synthetic method to fused polycyclic derivatives of isoquinoline is described via tandem reaction of isoquinoline, dialkyl acetylenedicarboxylates and dialkyl chloromalonate.
2013, 24(11): 984-986
Abstract:
A novel core-shell TiO2@ZnIn2S4 composite has been synthesized successfully by a simple and flexible hydrothermal route using TiO2 as precursors. The as-synthesized samples were characterized by X-ray diffraction, UV-vis diffuse reflectance spectra and transmission electron microscopy. The photocatalytic properties of samples were tested by degradation of aqueous methylene blue (MB) under visible light irradiation. It was found that the as-synthesized TiO2@ZnIn2S4 photocatalyst was more efficient than TiO2 and ZnIn2S4 in the photocatalytic degradation of MB. Moreover, TEM images confirmed the TiO2@ZnIn2S4 nanoparticles possessed a well-proportioned core-shell morphology.
A novel core-shell TiO2@ZnIn2S4 composite has been synthesized successfully by a simple and flexible hydrothermal route using TiO2 as precursors. The as-synthesized samples were characterized by X-ray diffraction, UV-vis diffuse reflectance spectra and transmission electron microscopy. The photocatalytic properties of samples were tested by degradation of aqueous methylene blue (MB) under visible light irradiation. It was found that the as-synthesized TiO2@ZnIn2S4 photocatalyst was more efficient than TiO2 and ZnIn2S4 in the photocatalytic degradation of MB. Moreover, TEM images confirmed the TiO2@ZnIn2S4 nanoparticles possessed a well-proportioned core-shell morphology.
2013, 24(11): 987-992
Abstract:
A pseudorotaxane and its polypseudorotaxanes formed between pillar[5]arene moieties and n-octylpyrazinium cations as novel fluorescent sensors for the selective detection of halogen ions were reported. A collapse of these pillar[5]arene-based pseudorotaxanes and polypseudorotaxanes occurred upon the addition of Cl-, Br-, and I-(tetrabutylammonium salts), respectively, leading to their fluorescence recovery. The fluorescence enhancement of the pseudorotaxane and the polypseudorotaxanes increases in the order of I-< Br-< Cl-, and the differences in fluorescence intensity could be easily distinguished by naked eyes under UV light illumination.
A pseudorotaxane and its polypseudorotaxanes formed between pillar[5]arene moieties and n-octylpyrazinium cations as novel fluorescent sensors for the selective detection of halogen ions were reported. A collapse of these pillar[5]arene-based pseudorotaxanes and polypseudorotaxanes occurred upon the addition of Cl-, Br-, and I-(tetrabutylammonium salts), respectively, leading to their fluorescence recovery. The fluorescence enhancement of the pseudorotaxane and the polypseudorotaxanes increases in the order of I-< Br-< Cl-, and the differences in fluorescence intensity could be easily distinguished by naked eyes under UV light illumination.
2013, 24(11): 993-996
Abstract:
An efficient method for the synthesis of imidazole derivatives by a three-component condensation of benzil or 9,10-phenanthrenequinone, aldehydes and ammonium acetate using supported ionic liquidlike phase (SILLP) catalyst under ultrasonic irradiation or classical heating conditions is reported. The present methodology offers several advantages, such as excellent yields, simple procedures, short reaction times, simple work-up and mild conditions. The catalyst is easily separated from the products by filtration and also exhibits remarkable reusable activity. These highly substituted imidazoles were also evaluated for their anti-microbial activity.
An efficient method for the synthesis of imidazole derivatives by a three-component condensation of benzil or 9,10-phenanthrenequinone, aldehydes and ammonium acetate using supported ionic liquidlike phase (SILLP) catalyst under ultrasonic irradiation or classical heating conditions is reported. The present methodology offers several advantages, such as excellent yields, simple procedures, short reaction times, simple work-up and mild conditions. The catalyst is easily separated from the products by filtration and also exhibits remarkable reusable activity. These highly substituted imidazoles were also evaluated for their anti-microbial activity.
2013, 24(11): 997-1000
Abstract:
The novel chelating sponge modified with hydroxamic acid groups was prepared by a grafting polymerization followed by a nucleophilic substitution reaction. Elementary analysis, SEM, FT-IR spectroscopy and XPS were used to characterize the spongy adsorbent (PVA-MA-HH). Adsorption isotherm study indicated that PVA-MA-HH had high equilibrium adsorption capacity for Cu2+.
The novel chelating sponge modified with hydroxamic acid groups was prepared by a grafting polymerization followed by a nucleophilic substitution reaction. Elementary analysis, SEM, FT-IR spectroscopy and XPS were used to characterize the spongy adsorbent (PVA-MA-HH). Adsorption isotherm study indicated that PVA-MA-HH had high equilibrium adsorption capacity for Cu2+.
2013, 24(11): 1001-1004
Abstract:
Structure-based virtual screening (molecular docking) is now one of the most pragmatic techniques to leverage target structure for ligand discovery. Accurate binding pose prediction is critical to molecular docking. Here, we describe a general strategy to improve the accuracy of docking pose prediction by implementing the structural descriptor-based filtering and KGS-penalty function-based conformational clustering in an unbiased manner. We assessed our method against 150 high-quality protein-ligand complex structures. Surprisingly, such simple components are sufficient to improve the accuracy of docking pose prediction. The success rate of predicting near-native docking pose increased from 53% of the targets to 78%. We expect that our strategymay have general usage in improving currently available molecular docking programs.
Structure-based virtual screening (molecular docking) is now one of the most pragmatic techniques to leverage target structure for ligand discovery. Accurate binding pose prediction is critical to molecular docking. Here, we describe a general strategy to improve the accuracy of docking pose prediction by implementing the structural descriptor-based filtering and KGS-penalty function-based conformational clustering in an unbiased manner. We assessed our method against 150 high-quality protein-ligand complex structures. Surprisingly, such simple components are sufficient to improve the accuracy of docking pose prediction. The success rate of predicting near-native docking pose increased from 53% of the targets to 78%. We expect that our strategymay have general usage in improving currently available molecular docking programs.
2013, 24(11): 1005-1007
Abstract:
The objective of this research is to utilize a new poly[N,N-diallyl pyrrolidinium bromide-co-N,N-dimethyl acrylamide-co-acrylic acid sodium salt] superabsorbent hydrogel (SAH) for the removal of two anionic dyes, e.g., Reactive Red 5B (RR5B) and Reactive Orange M2R (ROM2R), from water. The SAH was characterized by swelling in water, FTIR, TGA and SEM. The SAH DDA6 showed good swelling property and thermal stability. We have also investigated the parameters affecting dye adsorption such as pH, adsorbent dose, adsorption rate and initial dye concentration. The experimental data were also analyzed by applying the well known Langmuir and Freundlich isotherm models.
The objective of this research is to utilize a new poly[N,N-diallyl pyrrolidinium bromide-co-N,N-dimethyl acrylamide-co-acrylic acid sodium salt] superabsorbent hydrogel (SAH) for the removal of two anionic dyes, e.g., Reactive Red 5B (RR5B) and Reactive Orange M2R (ROM2R), from water. The SAH was characterized by swelling in water, FTIR, TGA and SEM. The SAH DDA6 showed good swelling property and thermal stability. We have also investigated the parameters affecting dye adsorption such as pH, adsorbent dose, adsorption rate and initial dye concentration. The experimental data were also analyzed by applying the well known Langmuir and Freundlich isotherm models.
2013, 24(11): 1008-1010
Abstract:
The electrochemical oxidation of 1,4-dihydroxyanthraquinone has been studied in the presence of acetylacetone and benzoylacetone as nucleophiles in a mixture of ethanol/water by means of cyclic voltammetry as a diagnostic technique. The results indicate the participation of electrochemically produced anthraquinone in the Michael addition reaction with acetylacetone and benzoylacetone to form the corresponding new anthraquinone derivatives. On the basis of the EC mechanism, the observed homogeneous rate constants (kobs) of the reaction of anthraquinone with acetylacetone and benzoylacetone were estimated by comparing the experimental cyclic voltammograms with the digitally simulated results.
The electrochemical oxidation of 1,4-dihydroxyanthraquinone has been studied in the presence of acetylacetone and benzoylacetone as nucleophiles in a mixture of ethanol/water by means of cyclic voltammetry as a diagnostic technique. The results indicate the participation of electrochemically produced anthraquinone in the Michael addition reaction with acetylacetone and benzoylacetone to form the corresponding new anthraquinone derivatives. On the basis of the EC mechanism, the observed homogeneous rate constants (kobs) of the reaction of anthraquinone with acetylacetone and benzoylacetone were estimated by comparing the experimental cyclic voltammograms with the digitally simulated results.
2013, 24(11): 1011-1013
Abstract:
5,10,15,20-Tetrakis(4-amidinophenyl)porphyrin (Por 1), its Zn complex (Por 2) and amidinophenyl bispophyrin (Por 3) interacting with calf thymus DNA were investigated by scanning electron microscopy (SEM) and the shape and size of the porphyrin-DNA complexes were observed after photo irradiation. The results showed that the shape and size of DNA had significant differences with blank group by virtue of the interaction between the porphyrins and ct-DNA. This suggests the morphological characterization could be used to study the interaction and judge DNA photocleavage activity indirectly through the photo irradiation of porphyrins.
5,10,15,20-Tetrakis(4-amidinophenyl)porphyrin (Por 1), its Zn complex (Por 2) and amidinophenyl bispophyrin (Por 3) interacting with calf thymus DNA were investigated by scanning electron microscopy (SEM) and the shape and size of the porphyrin-DNA complexes were observed after photo irradiation. The results showed that the shape and size of DNA had significant differences with blank group by virtue of the interaction between the porphyrins and ct-DNA. This suggests the morphological characterization could be used to study the interaction and judge DNA photocleavage activity indirectly through the photo irradiation of porphyrins.
2013, 24(11): 1014-1018
Abstract:
The preparation and performance characterization of <50 nm spirobenzopyran-based photochromic nanocomposites with photoswitchable fluorescence are presented. The nanocomposites were fabricated by means of a modified miniemulsion polymerization process, in which the hydrophobic spirobenzopyran was covalently attached to the polymer chains and the matched fluorescent dyes were noncovalently embedded in the nanoscale cross-linked polymeric matrix, respectively. The obtained nanocomposites with a high relative fluorescence quantum yield (Q) exhibited superior fluorescent photoswitchable performance due to the effective photo-induced intermolecular energy transfer. The stability of photomerocyanine was also improved.
The preparation and performance characterization of <50 nm spirobenzopyran-based photochromic nanocomposites with photoswitchable fluorescence are presented. The nanocomposites were fabricated by means of a modified miniemulsion polymerization process, in which the hydrophobic spirobenzopyran was covalently attached to the polymer chains and the matched fluorescent dyes were noncovalently embedded in the nanoscale cross-linked polymeric matrix, respectively. The obtained nanocomposites with a high relative fluorescence quantum yield (Q) exhibited superior fluorescent photoswitchable performance due to the effective photo-induced intermolecular energy transfer. The stability of photomerocyanine was also improved.
2013, 24(11): 1019-1022
Abstract:
A selective reaction of cyclohexanone oxime-blocked tolylene-2,4-diisocyanate (2,4-TDI) with amino siloxane was observed, in which amines were capable of discriminating two reactive groups in the 2,4-TDI molecule. Thus, tolylene-2-tert-butyldimethylsilyloxyethyl carbamide-4-cyclohexanone oxime carbamate was synthesized and its precise structure was determined by single-crystal X-ray diffraction. Moreover, it was found that oxime-blocked isocyanate could react selectively with the-NH2 group with the-OH group unprotected in ethanolamine.
A selective reaction of cyclohexanone oxime-blocked tolylene-2,4-diisocyanate (2,4-TDI) with amino siloxane was observed, in which amines were capable of discriminating two reactive groups in the 2,4-TDI molecule. Thus, tolylene-2-tert-butyldimethylsilyloxyethyl carbamide-4-cyclohexanone oxime carbamate was synthesized and its precise structure was determined by single-crystal X-ray diffraction. Moreover, it was found that oxime-blocked isocyanate could react selectively with the-NH2 group with the-OH group unprotected in ethanolamine.
2013, 24(11): 1023-1026
Abstract:
A series of hydrazone and N-acylhydrazone derivatives of dehydroabietic acid were synthesized and evaluated for BK channel-opening activities in an assay system of CHO-K1 cells expressing hBKa channels. The assay results indicated that the activities of the investigated compounds were influenced by the physicochemical properties of the substituent at hydrazone moiety.
A series of hydrazone and N-acylhydrazone derivatives of dehydroabietic acid were synthesized and evaluated for BK channel-opening activities in an assay system of CHO-K1 cells expressing hBKa channels. The assay results indicated that the activities of the investigated compounds were influenced by the physicochemical properties of the substituent at hydrazone moiety.
2013, 24(11): 1027-1029
Abstract:
A concise approach for the first total synthesis of two naturally occurring flavanoids, (±)-malaysianone A (1) and (±)-tanariflavanones B (2), has been accomplished with total yields of 12.9% and 10.4%, respectively. The key steps were regioselective deprotection and regioselective synthesis of 5-formaldehyde-8-hydroxy-2-[40-methyl-30-penteneyl]-dihydro-1-benzopyran (8).
A concise approach for the first total synthesis of two naturally occurring flavanoids, (±)-malaysianone A (1) and (±)-tanariflavanones B (2), has been accomplished with total yields of 12.9% and 10.4%, respectively. The key steps were regioselective deprotection and regioselective synthesis of 5-formaldehyde-8-hydroxy-2-[40-methyl-30-penteneyl]-dihydro-1-benzopyran (8).
2013, 24(11): 1030-1032
Abstract:
Two new sesquiterpenoids, attributable to eudesmane-type (1 and 2, named solajiangxins F and G), were isolated from the whole plant of Solanum lyratum. Their structures were elucidated on the basis of integrated spectroscopic techniques. In vitro, compounds 1 and 2 were found to show significant cytotoxic activity against selected cancer cells, including P-388, HONE-1 and HT-29.
Two new sesquiterpenoids, attributable to eudesmane-type (1 and 2, named solajiangxins F and G), were isolated from the whole plant of Solanum lyratum. Their structures were elucidated on the basis of integrated spectroscopic techniques. In vitro, compounds 1 and 2 were found to show significant cytotoxic activity against selected cancer cells, including P-388, HONE-1 and HT-29.
2013, 24(11): 1033-1036
Abstract:
A convenient, efficient and environmentally benign procedure has been developed for the synthesis of pyrano[4,3-b]pyran derivatives via a one-pot, three-component reaction of 4-hydroxy-6-methylpyran-2-one, aldehydes and malononitrile in water using H6P2W18O62·18H2O as catalyst. Reusability of the catalyst and reaction media, short reaction times and easy isolation of products are some added advantages of the present methodology.
A convenient, efficient and environmentally benign procedure has been developed for the synthesis of pyrano[4,3-b]pyran derivatives via a one-pot, three-component reaction of 4-hydroxy-6-methylpyran-2-one, aldehydes and malononitrile in water using H6P2W18O62·18H2O as catalyst. Reusability of the catalyst and reaction media, short reaction times and easy isolation of products are some added advantages of the present methodology.
