Feng Wang

Zhejiang University, Hang-hsien, Zhejiang Sheng, China

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Publications (31)153.01 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Conspectus Supramolecular polymers, fabricated via the combination of supramolecular chemistry and polymer science, are polymeric arrays of repeating units held together by reversible, relatively weak noncovalent interactions. The introduction of noncovalent interactions, such as hydrogen bonding, aromatic stacking interactions, metal coordination, and host-guest interactions, endows supramolecular polymers with unique stimuli responsiveness and self-adjusting abilities. As a result, diverse monomer structures have been designed and synthesized to construct various types of supramolecular polymers. By changing the noncovalent interaction types, numbers, or chemical structures of functional groups in these monomers, supramolecular polymeric materials can be prepared with tailored chemical and physical properties. In recent years, the interest in supramolecular polymers has been extended from the preparation of intriguing topological structures to the discoveries of potential applications as functional materials. Compared with traditional polymers, supramolecular polymers show some advantages in the fabrication of reversible or responsive materials. The development of supramolecular polymers also offers a platform to construct complex and sophisticated materials with a bottom-up approach. Macrocylic hosts, including crown ethers, cyclodextrins, calixarenes, cucurbiturils, and pillararenes, are the most commonly used building blocks in the fabrication of host-guest interaction-based supramolecular polymers. With the introduction of complementary guest molecules, macrocylic hosts demonstrate selective and stimuli-responsive host-guest complexation behaviors. By elaborate molecular design, the resultant supramolecular polymers can exhibit diverse structures based on the self-selectivity of host-guest interactions. The introduction of reversible host-guest interactions can further endow these supramolecular polymers with interesting and fascinating chemical/physical properties, including stimuli responsiveness, self-healing, and environmental adaptation. It has been reported that macrocycle-based supramolecular polymers can respond to pH change, photoirradition, anions, cations, temperature, and solvent. Macrocycle-based supramolecular polymers have been prepared in solution, in gel, and in the solid state. Furthermore, the solvent has a very important influence on the formation of these supramolecular polymers. Crown ether- and pillararene-based supramolecular polymers have mainly formed in organic solvents, such as chloroform, acetone, and acetonitrile, while cyclodextrin- and cucurbituril-based supramolecular polymerizations have been usually observed in aqueous solutions. For calixarenes, both organic solvents and water have been used as suitable media for supramolecular polymerization. With the development of supramolecular chemistry and polymer science, various methods, such as nuclear magnetic resonance spectroscopy, X-ray techniques, electron microscopies, and theoretical calculation and computer simulation, have been applied for characterizing supramolecular polymers. The fabrication of macrocycle-based supramolecular polymers has become a currently hot research topic. In this Account, we summarize recent results in the investigation of supramolecular polymers constructed from macrocycle-based host-guest molecular recognition motifs. These supramolecular polymers are classified based on the different macrocycles used in them. Their monomer design, structure control, stimuli-responsiveness, and applications in various areas are discussed, and future research directions are proposed. It is expected that the development of supramolecular polymers will not only change the way we live and work but also exert significant influence on scientific research.
    Accounts of Chemical Research 03/2014; · 20.83 Impact Factor
  • ChemInform 11/2012; 43(48).
  • ChemInform 05/2012; 43(22).
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    ABSTRACT: Supramolecular materials, dynamic materials by nature, are defined as materials whose components are bridged via reversible connections and undergo spontaneous and continuous assembly/disassembly processes under specific conditions. On account of the dynamic and reversible nature of noncovalent interactions, supramolecular polymers have the ability to adapt to their environment and possess a wide range of intriguing properties, such as degradability, shape-memory, and self-healing, making them unique candidates for supramolecular materials. In this critical review, we address recent developments in supramolecular polymeric materials, which can respond to appropriate external stimuli at the fundamental level due to the existence of noncovalent interactions of the building blocks.
    Chemical Society Reviews 05/2012; 41(18):6042-65. · 24.89 Impact Factor
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    ABSTRACT: Supramolecular polymers, polymeric systems beyond the molecule, have attracted more and more attention from scientists due to their applications in various fields, including stimuli-responsive materials, healable materials, and drug delivery. Due to their good selectivity and convenient enviro-responsiveness, crown ether-based molecular recognition motifs have been actively employed to fabricate supramolecular polymers with interesting properties and novel applications in recent years. In this tutorial review, we classify supramolecular polymers based on their differences in topology and cover recent advances in the marriage between crown ether-based molecular recognition and polymer science.
    Chemical Society Reviews 03/2012; 41(5):1621-36. · 24.89 Impact Factor
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    ABSTRACT: The objective of this study was to determine the fatty acid composition and physicochemical properties of ostrich fat obtained by supercritical fluid extraction. The fatty acid composition was analysed by GC-MS and the result revealed that ostrich fat contained 9-octadecenoic acid (40.7 ± 0.3%), hexadecanoic acid (32.5 ± 0.3%), octadecanoic acid (7.43 ± 0.05%), 9, 12-octadecadience acid (7.38 ± 0.02%) and 9-hexadecenoic acid (7.13 ± 0.15%) as the major components. Furthermore, seven physicochemical indexes were assessed according to Chinese Pharmacopeia (2005) and relevant regulations as follows: relative density (0.92 ± 0.02%), melting point (34.7 ± 0.4°C), acid value (0.84 ± 0.02 mg KOH/g), peroxide value (0.10 ± 0.01 g/100 g), saponification value (226 ± 3 mg KOH/g), ester value (225 ± 3 mg KOH/g) and iodine value (74.6 ± 0.8 g I/100 g). It can be inferred from the basic information that ostrich fat is a promising raw material for the pharmaceutical and cosmetics industries.Practical applications: With the increasing attention being paid to ostrich fat, it is necessary to elucidate the fatty acid composition and physicochemical properties of this natural product. This basic information not only reveals the essential characteristics of ostrich fat, but also provides the data support for the quality evaluation and efficacy research.
    European Journal of Lipid Science and Technology 02/2011; 113(6):775 - 779. · 2.27 Impact Factor
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    ABSTRACT: Antisolvent crystallization can be used as an alternative to cooling or evaporation for the separation and purification of solid product in the pharmaceutical industry. To improve the process understanding of antisolvent crystallization, the use of in-line tools is vital. In this study, the process analytical technology (PAT) tools including focused beam reflectance measurement (FBRM), particle video microscope (PVM), and near-infrared spectroscopy (NIRS) were utilized to monitor antisolvent crystallization of sodium scutellarein. FBRM was used to monitor chord count and chord length distribution of sodium scutellarein particles in the crystallizer, and PVM, as an in-line video camera, provided pictures imaging particle shape and dimension. In addition, a quantitative model of PLS was established by in-line NIRS to detect the concentration of sodium scutellarein in the solvent and good calibration statistics were obtained (r(2) = 0.976) with the residual predictive deviation value of 11.3. The discussion over sensitivities, strengths, and weaknesses of the PAT tools may be helpful in selection of suitable PAT techniques. These in-line techniques eliminate the need for sample preparation and offer a time-saving approach to understand and monitor antisolvent crystallization process.
    Journal of Pharmaceutical Sciences 01/2011; 100(6):2452-9. · 3.13 Impact Factor
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    ABSTRACT: Zizyphi spinosi semen (ZSS) has been widely used for treatment of insomnia in oriental countries. The aim of this study is to characterize the fatty oil of ZSS obtained by supercritical fluid extraction in terms of chemical composition and physicochemical properties. The chemical composition, including fatty acids and unsaponifiable constituents, was analyzed by gas chromatography–mass spectrometer (GC–MS). The results revealed that 9-octadecenoic acid (43.38±0.03%) and 9,12-octadecadienoic acid (40.58±0.03%) were the main fatty acids, and β-sitosterol (37.39±0.02%) and squalene (30.79±0.01%) were the key unsaponifiables. Furthermore, four indexes were assayed according to Chinese Pharmacopeia (2005) to reflect the physicochemical properties of ZSS oil, their values being determined as follows: acid value (10.3±0.1mg KOH/g), peroxide value (0.05±0.01g/100g), saponification value (194.4±0.5mg KOH/g) and iodine value (109.7±0.8g I/100g). The basic information obtained provides data support for quality evaluation and efficacy research of ZSS oil, and suggests its prospects for development in pharmaceutical and food industries. Keywords Zizyphi spinosi semen –Supercritical fluid extraction–Fatty oil–Chemical composition–Physicochemical properties–GC–MS
    Journal of Oil & Fat Industries 01/2011; 88(4):467-472. · 1.59 Impact Factor
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    ABSTRACT: Two [2]catenanes based on two different cryptand hosts, a dibenzo-24-crown-8-based cryptand and a bis(m-phenylene)-26-crown-8-based cryptand, have been synthesized and characterized. These two cryptand hosts only have a minor difference in chemical structure. However, this minor structural difference leads to big differences in the configurations and packing modes of the resulting catenanes. In addition, from the crystal structures of the two catenanes, we found that the cyclophane guest seems to have a selectivity algorithm and chooses the larger-size rings to go through and interlock with.
    Organic Letters 02/2010; 12(4):760-3. · 6.14 Impact Factor
  • Angewandte Chemie International Edition 02/2010; 49(6):1090-4. · 11.34 Impact Factor
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    ABSTRACT: Based on two self-sorting host-guest recognition motifs, novel linear main-chain polypseudorotaxanes with supramolecular polymer backbones have been constructed from three components in solution at high concentrations.
    Chemical Communications 09/2009; · 6.38 Impact Factor
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    ABSTRACT: A series of C7-O- and C20-O-amidated 2,3-dehydrosilybin (DHS) derivatives ((+/-)-1a-f and (+/-)-2), as well as a set of alkenylated DHS analogues ((+/-)-4a-f), were designed and de novo synthesized. A diesteric derivative of DHS ((+/-)-3) and two C23 esterified DHS analogues ((+/-)-5a and (+/-)-5b) were also prepared for comparison. The cell viability of PC12 cells, Fe(2+) chelation, lipid peroxidation (LPO), free radical scavenging, and xanthine oxidase inhibition models were utilized to evaluate their antioxidative and neuron protective properties. The study revealed that the diether at C7-OH and C20-OH as well as the monoether at C7-OH, which possess aliphatic substituted acetamides, demonstrated more potent LPO inhibition and Fe(2+) chelation compared to DHS and quercetin. Conversely, the diallyl ether at C7-OH and C20-OH was more potent in protection of PC12 cells against H(2)O(2)-induced injury than DHS and quercetin. Overall, the more lipophilic alkenylated DHS analogues were better performing neuroprotective agents than the acetamidated derivatives. The results in this study would be beneficial for optimizing the therapeutic potential of lignoflavonoids, especially in neurodegenerative disorders such as Alzheimer's and Parkinson's disease.
    Journal of Medicinal Chemistry 09/2009; 52(23):7732-52. · 5.61 Impact Factor
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    ABSTRACT: Twelve 23-esterified silybin derivatives with different patterns of substituents such as aromatic and aliphatic groups (1–12) were designed and synthesized. The antioxidative properties of these compounds were evaluated. The modified silybin analogues exhibited improved inhibitory effects against rat liver homogenate lipid peroxidation compared to silybin, with exception of the trimethoxylated ester (5) and the aliphatic one (9). Compounds 3, 5, 7, 8 and 11 displayed their protective properties on DNA cleavage in a dose-dependent manner.
    Chinese Chemical Letters 09/2009; 20(9):1030-1033. · 1.18 Impact Factor
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    ABSTRACT: Taco complex templation based on the bis(m-phenylene)-32-crown-10/paraquat recognition motif is used to develop a general method for preparing mechanically interlocked molecules. A [2]rotaxane and a [2]catenane were synthesized in high yields by a ring-closing metathesis reaction, which was owed to the impactful template effect. Due to the high symmetry of (5,5')-difunctional bis(m-phenylene)-32-crown-10 derivatives, this taco complex templated synthesis has potential to be a tempting method to solve a symmetry-based problem in the fabrication of complicated mechanically interlocked structures.
    Organic Letters 08/2009; 11(15):3350-3. · 6.14 Impact Factor
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    ABSTRACT: A diverse series of C-23 esterified silybin derivatives (1a-n) were designed and synthesized. The antioxidative properties of these compounds were evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide anion radical scavenging, ferrous ion chelation, and inhibition of rat liver homogenate lipid peroxidation. Their protective effects on the prevention of hydrogen peroxide induced DNA damage were also investigated. Most of the synthesized compounds exhibited more effective antioxidant activities than silybin. The esterified silybin analogues displayed satisfactory performance especially on iron chelation and antiperoxidative activity. Compound 1n in particular exhibited remarkable antiperoxidative effect with an IC(50) value of 0.2+/-0.1 microM, which was stronger than that of quercetin (IC(50)=1.8+/-0.6 microM). Compounds 1c, 1e, 1g, 1h and 1k displayed potent, dose-dependent protective properties against DNA cleavage. The results of the bioassays support the antioxidative and DNA protective effects of these synthesized silybin derivatives.
    Bioorganic & medicinal chemistry 08/2009; 17(17):6380-9. · 2.82 Impact Factor
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    ABSTRACT: Two three-dimensional catenanes have been successfully synthesized from a bis(m-phenylene)-32-crown-10-based cryptand and paraquat derivatives in reasonable yields.
    Organic & Biomolecular Chemistry 05/2009; 7(7):1288-91. · 3.57 Impact Factor
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    ABSTRACT: Two bis(m-phenylene)-32-crown-10 derivatives containing two pyridyl or carboxyl groups were made. They were used to prepare three bis(m-phenylene)-32-crown-10-based discrete rhomboids by coordination-driven self-assembly with high yields. The formation of these crown ether-based rhomboids was confirmed by NMR, UV-vis, CSI-TOF-MS, and elemental analysis. The complexation of these crown ether-based assemblies with paraquat (N,N'-dimethyl-4,4'-bipyridinium) was studied. The complexation of neutral bis(crown ether) rhomboid 1 with paraquat was found to be statistical with a 1:2 stoichiometry. The average apparent association constant K(av) of the complexation of rhomboid 1 with paraquat was found to be about 8.8(+/-0.8) x 10(3) M(-1) in acetone, about 17 times higher than the reported association constant value for the complexation of the corresponding simple bis(m-phenylene)-32-crown-10 with paraquat. This is possibly because the carboxylate groups provide additional noncovalent interactions between the host and guest. No obvious complexation was observed between the cationic rhomboids and paraquat when studied by NMR, UV-vis, and CSI-TOF-MS analysis. This could be attributed to the combination of the charge repulsion between cationic pyridinium rings and cationic platinum atoms and the weak pi-pi stacking and charge transfer interactions between the phenyl rings and the pyridinium rings caused by the electron-withdrawing effect of the cationic platinum atoms.
    The Journal of Organic Chemistry 05/2009; 74(10):3905-12. · 4.56 Impact Factor
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    ABSTRACT: BZYX was designed as a dual-binding-site acetylcholinesterase (AChE) inhibitor and selected from series of indanone derivatives. The present study was designed to examine the cognition-enhanced, anti-cholinesterase, and neuroprotective effects of BZYX. In the passive avoidance performance and radial arm maze, BZYX showed a comparable effect to donepezil and rivastigmine on memory deficits in different stages induced by scopolamine, NaNO(2) and ethanol, respectively. Ellman's assay indicated BZYX exhibited high inhibition on AChE activity. IC(50) values for BZYX: 0.058+/-0.022 microM; donepezil: 0.019+/-0.004 microM; rivastigmine: 3.81+/-2.81 microM; glantamine: 3.01+/-1.85 microM and huperzine A: 0.053+/-0.016 microM. BZYX also presented great neuroprotecive function from apoptosis induced by hydrogen peroxide(H(2)O(2)) in PC12 cells. MTT assay and Annexin V-FITC Apoptosis Detection showed the viability of PC12 cells remarkably decreased with 400 microM H(2)O(2), while it significantly increased when the cells were pretreated with 0.1-1.0 microM BZYX. BZYX pretreatment remarkably reversed the loss of mitochondria membrane potential (DeltaPsim), scavenged reactive oxygen species formation induced by H(2)O(2) and resulted in up-regulation of procaspase3 and xIAP protein level and down-regulation of phosphorylated JNK protein, p53 protein level and cleavage of caspase 3. It is speculated that the mitochondrial pathway, mediated by Bcl-2 family and Mitogen-Activated Protein Kinases (MAPKs), might involved in the neuroprotection of BZYX. These results first demonstrated that BZYX had neuroprotective effects as well as cognition enhancement and acetylcholinesterase inhibition. It is hopeful that BZYX becomes a potential candidate for use in the intervention for neurodegenerative diseases.
    European journal of pharmacology 05/2009; 613(1-3):1-9. · 2.59 Impact Factor
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    ABSTRACT: An unusual class of 5,6,7-trioxygenated dihydroflavonols (3a-e and 4a-j) were designed and prepared. Their antioxidative properties were assessed by examining their capacities in several in vitro models, including superoxide anion and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, rat liver homogenate lipid peroxidation inhibition, PC12 cells protection from oxidative damage, and xanthine oxidase inhibition. These dihydroflavonols displayed positive quenching abilities towards O(2)(-) and DPPH free radicals, in which the majority exhibited superior antioxidant properties to Vitamin C. cis-Configurated compound (+/-)-3e demonstrated remarkable inhibition to LPO with an IC(50) value of 1.9+/-0.3 microM, which was apparently stronger than that of quercetin (IC(50)=6.0+/-0.4 microM). trans-Configurated dihydroflavonol (+/-)-4h exhibited significant protective effect on PC12 cells against oxidative damage with an EC(50) value of 41.5+/-5.3 microM, more effective compared to that of quercetin (EC(50)=81.8+/-8.7 microM). The 6-OH-5,7-dimethoxy analogue (+/-)-3d showed significant inhibition of xanthine oxidase with an IC(50) value of 16.0+/-0.8 microM, which is superior to that of allopurinol (IC(50)=23.5+/-2.0 microM). In addition to the hypothesized action mechanism of the bio-active compounds, 3D modeling was used to analyze the relationship between the minimized-energy structures and antioxidant activities.
    Bioorganic & medicinal chemistry 04/2009; 17(9):3414-25. · 2.82 Impact Factor
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    ABSTRACT: It has been demonstrated that the complexation of the divalent salts of paraquat can be greatly improved (a K(a) increase up to 219 times was observed) by the introduction of ion-pair recognition through use of urea moieties on the crown ether. This improvement is controlled by not only the solvent polarity but also the nature of the anion. Furthermore, it was found that the binding motif for paraquat guest incorporation into the heteroditopic host is anion-controlled in the solid state. The host-guest complex is a pseudorotaxane in the solid state when the two counterions of paraquat are trifluoroacetate anions while it is a taco complex when the two counterions are hexafluorophosphate or chloride anions.
    The Journal of Organic Chemistry 02/2009; 74(3):1322-8. · 4.56 Impact Factor