scholarly journals β-Cyclodextrin- and adamantyl-substituted poly(acrylate) self-assembling aqueous networks designed for controlled complexation and release of small molecules

2017 ◽  
Vol 13 ◽  
pp. 1879-1892 ◽  
Author(s):  
Liang Yan ◽  
Duc-Truc Pham ◽  
Philip Clements ◽  
Stephen F Lincoln ◽  
Jie Wang ◽  
...  
Keyword(s):  
Methyl Orange ◽  
Small Molecules ◽  
Controlled Drug Release ◽  
Methyl Red ◽  
Dialysis Membrane ◽  
Factors Affecting ◽  
H Nmr ◽  
Self Assembling ◽  
Vis Spectroscopy ◽  
Insight Into

Three aqueous self-assembling poly(acrylate) networks have been designed to gain insight into the factors controlling the complexation and release of small molecules within them. These networks are formed between 8.8% 6A-(2-aminoethyl)amino-6A-deoxy-6A-β-cyclodextrin, β-CDen, randomly substituted poly(acrylate), PAAβ-CDen, and one of the 3.3% 1-(2-aminoethyl)amidoadamantyl, ADen, 3.0% 1-(6-aminohexyl)amidoadamantyl, ADhn, or 2.9% 1-(12-aminododecyl)amidoadamantyl, ADddn, randomly substituted poly(acrylate)s, PAAADen, PAAADhn and PAAADddn, respectively, such that the ratio of β-CDen to adamantyl substituents is ca. 3:1. The variation of the characteristics of the complexation of the dyes methyl red, methyl orange and ethyl orange in these three networks and by β-cyclodextrin, β-CD, and PAAβ-CDen alone provides insight into the factors affecting dye complexation. The rates of release of the dyes through a dialysis membrane from the three aqueous networks show a high dependence on host–guest complexation between the β-CDen substituents and the dyes as well as the structure and the viscosity of the network as shown by ITC, 1H NMR and UV–vis spectroscopy, and rheological studies. Such networks potentially form a basis for the design of controlled drug release systems.

scholarly journals Synthesis of photoresponsive cholesterol-based azobenzene organogels: dependence on different spacer lengths

2015 ◽  
Vol 11 ◽  
pp. 1089-1095 ◽  
Author(s):  
Yuchun Ren ◽  
Bin Wang ◽  
Xiuqing Zhang
Keyword(s):  
Nmr Spectroscopy ◽  
Crucial Role ◽  
Molecular Structures ◽  
H Nmr ◽  
Vis Spectroscopy ◽  
Thermal Phase ◽  
Reversible Gel ◽  
Phase Behaviors ◽  
Insight Into ◽  
C Nmr

A series of azobenzene–cholesterol organogel compounds (M 0 –M 12 ) with different spacers were designed and synthesized. The molecular structures were confirmed by 1H NMR and 13C NMR spectroscopy. The rapid and reversible photoresponsive properties of the compounds were investigated by UV–vis spectroscopy. Their thermal phase behaviors were studied by DSC. The length of the spacer plays a crucial role in the gelation. Compound M 6 is the only one that can gelate in ethanol, isopropanol and 1-butanol and the reversible gel–sol transitions are also investigated. To obtain visual insight into the microstructure of the gels, the typical structures of the xerogels were studied by SEM. Morphologies of the aggregates change from flower-like, network and rod with different sizes. By using IR and XRD characterization, it is found that intermolecular H-bonding, the solvents and van der Waals interaction are the main contributions to the specific superstructure.

Factors Affecting Molecular Self-Assembly and Its Mechanism

2012 ◽  
Vol 9 (1) ◽  
pp. 43 ◽  
Author(s):  
Hueyling Tan
Keyword(s):  
Self Assembly ◽  
Building Blocks ◽  
Molecular Engineering ◽  
Molecular Structures ◽  
Polymer Science ◽  
New Approach ◽  
Factors Affecting ◽  
Dna Structures ◽  
Self Assembling ◽  
Wide Range

Molecular self-assembly is ubiquitous in nature and has emerged as a new approach to produce new materials in chemistry, engineering, nanotechnology, polymer science and materials. Molecular self-assembly has been attracting increasing interest from the scientific community in recent years due to its importance in understanding biology and a variety of diseases at the molecular level. In the last few years, considerable advances have been made in the use ofpeptides as building blocks to produce biological materials for wide range of applications, including fabricating novel supra-molecular structures and scaffolding for tissue repair. The study ofbiological self-assembly systems represents a significant advancement in molecular engineering and is a rapidly growing scientific and engineering field that crosses the boundaries ofexisting disciplines. Many self-assembling systems are rangefrom bi- andtri-block copolymers to DNA structures as well as simple and complex proteins andpeptides. The ultimate goal is to harness molecular self-assembly such that design andcontrol ofbottom-up processes is achieved thereby enabling exploitation of structures developed at the meso- and macro-scopic scale for the purposes oflife and non-life science applications. Such aspirations can be achievedthrough understanding thefundamental principles behind the selforganisation and self-synthesis processes exhibited by biological systems.

Photocatalytic Degradation of Methyl Orange Dye with Synthesized Chitosan/Fe2O3Nanocomposite and its Isotherm Studies.

2020 ◽  
Vol 16 ◽  
Author(s):  
Nimisha Jadon ◽  
Gulzar Ahmad Bhat ◽  
Manoharmayum Vishwanath Sharma ◽  
Harendra Kumar Sharma
Keyword(s):  
Methyl Orange ◽  
Dye Degradation ◽  
Dose Effect ◽  
X Ray Diffraction ◽  
Methyl Orange Degradation ◽  
Transmission Electron ◽  
Fourier Transformation Infrared Spectroscopy ◽  
Vis Spectroscopy ◽  
Methyl Orange Dye ◽  
Degradation Of Methyl Orange

Background: The study focuses on the synthesis of chitosan/ Fe2O3 nanocomposite, its characterization and application in methyl orange dye degradation. Methods: The synthesized chitosan/ Fe2O3 nanocomposite was characterized with Powder X-Ray Diffraction, Fourier Transformation Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and UV-Vis Spectroscopy. Results: The characterization showed that the Fe2O3nanoparticles were embedded in the polymer matrix of chitosan. The size of the Fe2O3nanoparticles were less than 10nm and the crystallite size was 1.22 nm.The synthesized chitosan/ Fe2O3nanocomposite was tested for methyl orange degradation using different parameters such as effect of contact time, effect of dose, effect of concentration and effect of pH for the degradation of methyl orange dye in aqueous solution.The Fruendlich, Langmuir and Temkin isotherm studies were also conducted for adsoption of methyl orange on Chitosan/ Fe2O3nanocomposite. Conclusion: The study indicated that the synthesized chitosan/Fe2O3 nanocomposite had the potential of degrading methyl orange dye up to 75.04% under the set condition in this experiment which indicate that Chitosan/ Fe2O3 nanocomposite is a viable option that can be used for the degradation of methyl orange dye.

scholarly journals Transcriptomic and chemical analyses to identify candidate genes involved in color variation of sainfoin flowers

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yu Qiao ◽  
Qiming Cheng ◽  
Yutong Zhang ◽  
Wei Yan ◽  
Fengyan Yi ◽  
...  
Keyword(s):  
Regulatory Networks ◽  
Flower Color ◽  
Color Variation ◽  
Anthocyanin Synthesis ◽  
Flower Formation ◽  
Factors Affecting ◽  
Phenylpropanoid Biosynthesis ◽  
Molecular Information ◽  
Illumina Hiseq4000 ◽  
Insight Into

Abstract Background Sainfoin (Onobrychis viciifolia Scop) is not only a high-quality legume forage, but also a nectar-producing plant. Therefore, the flower color of sainfoin is an important agronomic trait, but the factors affecting its flower phenotype are still unclear. To gain insights into the regulatory networks associated with metabolic pathways of coloration compounds (flavonoids or anthocyanins) and identify the key genes, we conducted a comprehensive analysis of the phenotype, metabolome and transcriptome of WF and AF of sainfoin. Results Delphinidin, petunidin and malvidin derivatives were the main anthocyanin compounds in the AF of sainfoin. These substances were not detected in the WF of sainfoin. The transcriptomes of WF and AF in sainfoin at the S1 and S3 stages were obtained using the Illumina HiSeq4000 platform. Overall, 10,166 (4273 upregulated and 5893 downregulated) and 15,334 (8174 upregulated and 7160 downregulated) DEGs were identified in flowers at S1 and S3 stages, respectively (WF-VS-AF). KEGG pathway annotations showed that 6396 unigenes were annotated to 120 pathways and contained 866 DEGs at S1 stages, and 6396 unigenes were annotated to 131 pathways and included 1546 DEGs at the S3 stage. Nine DEGs belonging to the “flavonoid biosynthesis”and “phenylpropanoid biosynthesis” pathways involved in flower color formation were identified and verified by RT-qPCR analyses. Among these DEGs, 4CL3, FLS, ANS, CHS, DFR and CHI2 exhibited downregulated expression, and F3H exhibited upregulated expression in the WF compared to the AF, resulting in a decrease in anthocyanin synthesis and the formation of WF in sainfoin. Conclusions This study is the first to use transcriptome technology to study the mechanism of white flower formation in sainfoin. Our transcriptome data will be a great enrichment of the genetic information for sainfoin. In addition, the data presented herein will provide valuable molecular information for genetic breeding and provide insight into the future study of flower color polymorphisms in sainfoin.

scholarly journals Structural analysis of cross α-helical nanotubes provides insight into the designability of filamentous peptide nanomaterials

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Fengbin Wang ◽  
Ordy Gnewou ◽  
Charles Modlin ◽  
Leticia C. Beltran ◽  
Chunfu Xu ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Synthetic Peptide ◽  
Quaternary Structure ◽  
De Novo ◽  
Rational Approach ◽  
Lateral Interactions ◽  
Protein Assemblies ◽  
Self Assembling ◽  
Arginine Residues ◽  
Insight Into

AbstractThe exquisite structure-function correlations observed in filamentous protein assemblies provide a paradigm for the design of synthetic peptide-based nanomaterials. However, the plasticity of quaternary structure in sequence-space and the lability of helical symmetry present significant challenges to the de novo design and structural analysis of such filaments. Here, we describe a rational approach to design self-assembling peptide nanotubes based on controlling lateral interactions between protofilaments having an unusual cross-α supramolecular architecture. Near-atomic resolution cryo-EM structural analysis of seven designed nanotubes provides insight into the designability of interfaces within these synthetic peptide assemblies and identifies a non-native structural interaction based on a pair of arginine residues. This arginine clasp motif can robustly mediate cohesive interactions between protofilaments within the cross-α nanotubes. The structure of the resultant assemblies can be controlled through the sequence and length of the peptide subunits, which generates synthetic peptide filaments of similar dimensions to flagella and pili.

scholarly journals Factors affecting presence and relative abundance of the Endangered volcano rabbit Romerolagus diazi, a habitat specialist

Oryx ◽  
2021 ◽  
pp. 1-10
Author(s):  
Felipe Osuna ◽  
Roger Guevara ◽  
Enrique Martínez-Meyer ◽  
Raúl Alcalá ◽  
Alejandro Espinosa de los Monteros
Keyword(s):  
Sierra Nevada ◽  
Relative Abundance ◽  
Linear Models ◽  
Cattle Grazing ◽  
Patch Occupancy ◽  
Factors Affecting ◽  
Rock Cover ◽  
Volcanic Fields ◽  
Mountain Grasslands ◽  
Insight Into

Abstract Habitat specialists are particularly vulnerable to extinction when habitat conditions are altered. Information on the habitat use of such species is thus important because it provides insight into factors that influence distribution and abundance, which is crucial for conservation. Here, we aimed to identify factors that influence the patterns of presence and abundance of the Endangered volcano rabbit Romerolagus diazi, a rare leporid with a patchy distribution. Through exhaustive sampling of its range in the Sierra Chichinautzin and Sierra Nevada volcanic fields, Mexico, and using generalized linear models, we found that the probability of patch occupancy was higher where bunchgrass cover exceeded 75%, rock cover exceeded 5%, no cattle grazing was observed and human settlements were at least 7 km away. Patches with greater relative abundance were those with similar characteristics, but located at elevations > 3,600 m, and with rock cover < 15%. Cattle grazing was identified as a major threat to local populations of the volcano rabbit, particularly in the Sierra Chichinautzin. Because of the significance of bunchgrasses for this species, the protection of the mountain grasslands is required in both volcanic fields.

Synthesis and spectral characterization of bis(β-diketonato)zirconium(IV) and -hafnium(IV) phthalocyaninates

2002 ◽  
Vol 06 (02) ◽  
pp. 114-121 ◽  
Author(s):  
L. A. Tomachynski ◽  
V. Ya. Chernii ◽  
S. V. Volkov
Keyword(s):  
Organic Solvents ◽  
Elemental Analysis ◽  
Central Atom ◽  
Spectral Characterization ◽  
H Nmr ◽  
Vis Spectroscopy ◽  
Cl Atoms

The reaction of PcMCl 2 ( M = Zr , Hf ) with β-diketones is reported. 1 H NMR and elemental analysis suggest the substitution of two Cl atoms for two β-diketone fragments takes place as a result of this reaction and the complexes PcM(β-dik)2 are formed. All obtained complexes are stable and highly soluble in most organic solvents. The data from 1 H and 19 F NMR, and UV-vis spectroscopy suggest the coordination of two β-diketone ligands in a cis geometry about the central atom of the macrocycle. It was shown bis(β-diketonato)zirconium(IV) and hafnium(IV) phthalocyanines containing β-diketones with donor or acceptor groups or with bulky substituents can be obtained.

scholarly journals Controlled drug release to cancer cells from modular one-photon visible light-responsive micellar system

2016 ◽  
Vol 52 (69) ◽  
pp. 10525-10528 ◽  
Author(s):  
Saemi O. Poelma ◽  
Seung Soo Oh ◽  
Sameh Helmy ◽  
Abigail S. Knight ◽  
G. Leslie Burnett ◽  
...  
Keyword(s):  
Drug Release ◽  
Visible Light ◽  
Small Molecules ◽  
Cancer Cells ◽  
Controlled Drug Release ◽  
Micellar System ◽  
On Demand ◽  
System P

We present a one-photon visible light-responsive micellar system for efficient, on-demand delivery of small molecules.

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