Molecular dynamics study on the interaction between doxorubicin and hydrophobically modified chitosan oligosaccharide

RSC Advances ◽  
2014 ◽  
Vol 4 (45) ◽  
pp. 23730-23739 ◽  
Author(s):  
Peng Shan ◽  
Jia-Wei Shen ◽  
Dong-Hang Xu ◽  
Li-Yun Shi ◽  
Jie Gao ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Hydrophobic Interactions ◽  
Chitosan Oligosaccharide ◽  
Π Interactions ◽  
Modified Chitosan ◽  
Chitosan Oligosaccharides ◽  
Hydrophobically Modified

Both π–π interactions and hydrophobic interactions were found to be essential for the loading of doxorubicin on hydrophobically modified chitosan oligosaccharides.

Molecular Basis of Iterative C–H Oxidation by TamI, a Multifunctional P450 Monooxygenase from the Tirandamycin Biosynthetic Pathway

2020 ◽  
Author(s):  
Sean A. Newmister ◽  
Kinshuk Raj Srivastava ◽  
Rosa V. Espinoza ◽  
Kersti Caddell Haatveit ◽  
Yogan Khatri ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Molecular Basis ◽  
Hydrophobic Interactions ◽  
Cytochromes P450 ◽  
Targeted Mutagenesis ◽  
P450 Monooxygenase ◽  
Bond Functionalization ◽  
Dynamics Simulations

Biocatalysis offers an expanding and powerful strategy to construct and diversify complex molecules by C-H bond functionalization. Due to their high selectivity, enzymes have become an essential tool for C-H bond functionalization and offer complementary reactivity to small-molecule catalysts. Hemoproteins, particularly cytochromes P450, have proven effective for selective oxidation of unactivated C-H bonds. Previously, we reported the in vitro characterization of an oxidative tailoring cascade in which TamI, a multifunctional P450 functions co-dependently with the TamL flavoprotein to catalyze regio- and stereoselective hydroxylations and epoxidation to yield tirandamycin A and tirandamycin B. TamI follows a defined order including 1) C10 hydroxylation, 2) C11/C12 epoxidation, and 3) C18 hydroxylation. Here we present a structural, biochemical, and computational investigation of TamI to understand the molecular basis of its substrate binding, diverse reactivity, and specific reaction sequence. The crystal structure of TamI in complex with tirandamycin C together with molecular dynamics simulations and targeted mutagenesis suggest that hydrophobic interactions with the polyene chain of its natural substrate are critical for molecular recognition. QM/MM calculations and molecular dynamics simulations of TamI with variant substrates provided detailed information on the molecular basis of sequential reactivity, and pattern of regio- and stereo-selectivity in catalyzing the three-step oxidative cascade.<br>

scholarly journals Antibacterial Activity of N,O-Acylated Chitosan Derivative

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 107
Author(s):  
Agnieszka Piegat ◽  
Anna Żywicka ◽  
Agata Niemczyk ◽  
Agata Goszczyńska
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Chitosan Derivative ◽  
Modified Chitosan ◽  
Microdilution Method ◽  
Hydrophobically Modified ◽  
Mechanism Of Interaction ◽  
H Pylori ◽  
Living Bacteria ◽  
Antibacterial Potential

The antibacterial activity of N,O-acylated chitosan derivative with linoleic acid (CH_LA) was tested by disc and well diffusion, agar impregnation and microdilution methods against Staphylococcus aureus, Escherichia coli and Helicobacter pylori strains. Hydrophobically modified chitosan (HMC) was expected to exhibit enhanced antibacterial activity and specific mucin interactions. Although diffusion tests have not indicated the antibacterial potential of chitosan (CH) or CH_LA, the results of the microdilution method demonstrated that tested polymers significantly reduced the amount of living bacteria cells in different concentrations depending on the microorganism. Additionally, CH_LA was characterized by enhanced antibacterial activity compared to CH, which may suggest a different mechanism of interaction with S. aureus and H. pylori. Furthermore, the UV-VIS analysis revealed that the amphiphilic character of derivative led to strong CH_LA–mucin interactions. The study proved the high potential of CH_LA in antibacterial applications, especially for the gastrointestinal tract.

scholarly journals Pre-Harvest Treatment of Chitosan Oligosaccharides Improved Strawberry Fruit Quality

2018 ◽  
Vol 19 (8) ◽  
pp. 2194 ◽  
Author(s):  
Yanqiu He ◽  
Santosh Bose ◽  
Wenxia Wang ◽  
Xiaochen Jia ◽  
Hang Lu ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plant Immunity ◽  
Titratable Acidity ◽  
Growth Stages ◽  
Chitosan Oligosaccharide ◽  
Uniform Size ◽  
Chitosan Oligosaccharides ◽  
Soluble Solid ◽  
Regulated Gene Expression

Chitosan oligosaccharide (COS), derived through hydrolysis of chitosan, has been proved to be an effective plant immunity elicitor, eco-friendly, and easily soluble in water, and influenced several secondary metabolites content to improve fruit qualities. COS are widely used in agriculture to improve the defense response in plants. The purpose of this study was to investigate the pre-harvest treatment effect of COS on the quality of strawberry (Fragaria × ananassa cv.qingxiang). COS was dissolved in distilled water at a concentration of 50 mg·L−1 and sprayed at four different growth stages of strawberry plants, namely seedling stage, before flowering, fruit coloring (the stage of fruit from white to red) and full bloom. Uniform size, shape, color, without any visible damage, and disease-free fruits were harvested for determining the quality. The results showed that the fruit firmness, viscosity, lignin, sugars, protein, total soluble solid, and titratable acidity content increased in COS-treated fruits compared to control. In addition, COS pre-harvest treatment had a positive effect on anthocyanin, total phenol, flavonoid, vitamin C content and DPPH(2,2-diphenyl-1-picrylhydrazyl) scavenging activity of strawberry. Moreover, COS also increased the cell wall composition and regulated gene expression of some important enzymes involved in ethylene compound biosynthesis and cell wall degradation. The finding of this study suggests that pre-harvest application of COS is very useful for improving quality and antioxidant capacity of strawberry.

scholarly journals Chitosan Oligosaccharides Stimulate the Efficacy of Somatic Embryogenesis in Different Genotypes of the Liriodendron Hybrid

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 557
Author(s):  
Asif Ali ◽  
Jiaji Zhang ◽  
Minmin Zhou ◽  
Tingting Chen ◽  
Liaqat Shah ◽  
...  
Keyword(s):  
Somatic Embryogenesis ◽  
Antagonistic Effect ◽  
Growth Speed ◽  
Chitosan Oligosaccharide ◽  
Chitosan Oligosaccharides ◽  
Germination Ability ◽  
Auxin Synthesis ◽  
Branch Development ◽  
The Impact ◽  
Seed Setting Rate

Liriodendron hybrid (L. chinense × L. tulipifera), an essential medium-sized tree generally famous for its timber, is also used as an ornamental and greenery tool in many places around the world. The Liriodendron hybrid (L. hybrid) tree goes through many hurdles to achieve its maximum strength and vigor, such as loss of habitat, vast genetic variation, and low seed setting rate. The establishment of an effective and well-organized somatic embryogenesis (S.E.) system could be used to overcome these obstacles, rather than the old-fashioned seed culture and organogenesis. This study is based on the impact of chitosan oligosaccharide (COS) and its role in the induction of S.E. on the callus of four genotypes of the L. hybrid. The optimal concentration of COS could enhance the momentum and effectiveness in S.E.’s mechanism, which further improves the growth rate of the L. hybrid tree’s plantlets. This study shows that COS has a prominent role in endogenous hormones like indole acetic acid (IAA), zeatin (Z.T.), and gibberellic acid (GA3). Furthermore, COS improves the growth development, growth speed, as well as the development situation of plant germination ability. COS can also regulate branch development and root growth, which could be linked to the antagonistic effect on growth factors to some extent or by affecting auxin synthesis and polar transport.

scholarly journals Hydrophobically modified chitosan nanoliposomes for intestinal drug delivery

2018 ◽  
Vol Volume 13 ◽  
pp. 5837-5848 ◽  
Author(s):  
M Gulrez Zariwala ◽  
Harshada Bendre ◽  
Anatoliy Markiv ◽  
Sebastien Farnaud ◽  
Derek Renshaw ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Modified Chitosan ◽  
Hydrophobically Modified

scholarly journals Polypharmacology of Some Medicinal Plant Metabolites Against SARS-CoV-2 and Host Targets: Molecular Dynamics Evaluation of NSP9 RNA Binding Protein

2020 ◽  
Author(s):  
Suritra Bandyopadhyay ◽  
Omobolanle Abimbola Abiodun ◽  
Blessing Chinweotito Ogboo ◽  
Adeola Tawakalitu Kola-Mustapha ◽  
Emmanuel Ifeanyi Attah ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Medicinal Plants ◽  
Active Sites ◽  
Rna Binding ◽  
Hydrophobic Interactions ◽  
Binding Energies ◽  
Dynamics Simulation ◽  
Receptor Interaction ◽  
Plant Metabolites ◽  
Structure Comparison

<p><b>Background: </b>Medicinal plants, as rich sources of bioactive compounds with antiviral properties, are now being explored for the development of drugs against SARS-CoV-2.</p><p><b>Aims: </b>Identification of promising compounds for the treatment of COVID-19 from natural products via molecular modelling against NSP9, including some other viral and host targets and evaluation of polypharmacological indications.</p><p><b>Main methods: </b>A manually curated library of 521 phytochemicals (from 19 medicinal plants) was virtually screened using Mcule server and binding interactions were studied using DS Visualiser. Docking thresholds were set based on the scores of standard controls and rigorous ADMET properties were used to finally get the potential inhibitors. Free binding energies of the docked complexes were calculated employing MM-GBSA method. MM-GBSA informed our choice for MD simulation studies performed against NSP9 to study the stability of the drug-receptor interaction. NSP9 structure comparison was also performed. </p><p><b>Key findings: </b>Extensive screening of the molecules identified 5 leads for NSP9, 23 for Furin, 18 for ORF3a, and 19 for interleukin-6. Ochnaflavone and Licoflavone B, obtained from Lonicera japonica (Japanese Honeysuckle) and Glycyrrhiza glabra (Licorice), respectively, were identified to have the highest potential multi-target inhibition properties for NSP9, furin, ORF3a, and IL-6. Additionally, molecular dynamics simulation supports the robust stability of Ochnaflavone and Licoflavone B against NSP9 at the active sites via hydrophobic interactions, H-bonding, and H-bonding facilitated by water.</p><b>Significance:</b> These compounds with the highest drug-like ranking against multiple viral and host targets have the potential to be drug candidates for the treatment of SARS-CoV-2 infection that may possibly act on multiple pathways simultaneously to inhibit viral entry and replication as well as disease progression.

Injectable hydrogel composed of hydrophobically modified chitosan/oxidized-dextran for wound healing

2019 ◽  
Vol 104 ◽  
pp. 109930 ◽  
Author(s):  
Xinchen Du ◽  
Yujie Liu ◽  
Xin Wang ◽  
Hongyu Yan ◽  
Lina Wang ◽  
...  
Keyword(s):  
Wound Healing ◽  
Injectable Hydrogel ◽  
Oxidized Dextran ◽  
Modified Chitosan ◽  
Hydrophobically Modified
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