scholarly journals Syntheses of Cyanophycin Segments for Investigations of Cell-Penetration

Synthesis ◽  
2018 ◽  
Vol 51 (01) ◽  
pp. 31-39 ◽  
Author(s):  
Marcel Grogg ◽  
Donald Hilvert ◽  
Albert Beck ◽  
Dieter Seebach
Keyword(s):  
Solid State ◽  
Building Blocks ◽  
Acid Group ◽  
Preparative Hplc ◽  
Side Chains ◽  
The Novel ◽  
Cell Penetration ◽  
Carboxylic Acid Group ◽  
Amide Derivatives ◽  
Cell Penetrating

Novel guanidinium-rich oligopeptide derivatives R-[Adp(X)]8-NH2 are described, which consist of an octa-aspartic acid backbone with argininylated side chains that are derived from the biopolymer cyanophycin [H-(Adp)n-OH]. The Fmoc-Adp(X,Pbf)-OH building blocks for solid-state peptide synthesis (SSPS) of Adp octamers were prepared from Fmoc-Arg(Pbf)-OH and Fmoc-Asp-OAll. Coupling on PAL resin provided four octamers with and without N-terminal fluorescent groups (FAM) and C-terminal amide groups. Milligram quantities of Adp-octamers were isolated after preparative HPLC purification. The structure of the novel guanidinium-rich oligomers is unique insofar as the side chains of the Asp8-backbone include both a guanidino and a carboxylic acid group, the influence of which will be tested with the corresponding ester and amide derivatives that were synthesized in parallel. Unusual cell-penetrating properties of the Adp-octamers are expected.

Bioerodible Polypyrrole

2001 ◽  
Vol 711 ◽  
Author(s):  
Alexander Zelikin ◽  
Venkatram Shastri ◽  
David Lynn ◽  
Jian Farhadi ◽  
Ivan Martin ◽  
...  
Keyword(s):  
Erosion Rate ◽  
Acid Group ◽  
The Novel ◽  
Carboxylic Acid Group ◽  
Polymer Backbone ◽  
Cellular Processes ◽  
Novel Approach ◽  
Efficient Control ◽  
And Function ◽  
Substrate Independent

ABSTRACTConductive polymers such as polypyrrole (Ppy) are potentially useful as an active interface for altering cellular processes and function. Their utilization in medically related applications however have been substantially held back by their non-degradable nature. Herein we report a novel approach to creation of bioerodible polypyrroles via modification of pyrrole beta-carbon with an ionizable moiety. It has been shown that the erosion rate of acid-bearing derivative of polypyrrole increases with pH, which is consistent with the pH dependent ionization of carboxylic acid group. The novel paradigm proposed for the creation of bioerodible polypyrroles allows for simple and efficient control over the erosion rate of the substrate independent of the polymer chain length, via the choice of the terminal ionizable group and its concentration along the polymer backbone.

scholarly journals Synthesis and Cytotoxic Evaluation of Carboxylic Acid-Functionalized Indenoisoquinolines

2019 ◽  
Vol 14 (5) ◽  
pp. 1934578X1984978 ◽  
Author(s):  
Nguyen Tien Dung ◽  
Le Nhat Thuy Giang ◽  
Pham Hoai Thu ◽  
Ngo Hanh Thuong ◽  
Dang Thi Tuyet Anh ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Cancer Cells ◽  
Spectral Methods ◽  
Acid Group ◽  
Side Chain ◽  
Cytotoxic Activities ◽  
Side Chains ◽  
Carboxylic Acid Group ◽  
New Compounds

In order to find out the influence of carboxylic acid functionalities in the N-lactam side chains of indenoisoquinolines on cytotoxic activities, several new compounds have been synthesized and structurally characterized by analytical and spectral methods. The incorporation of a carboxylic acid group into the lactam side chain of indenoisoquinolines results in differences in cytotoxicity. The results indicated that compound 18c displayed substantial cytotoxic specificity toward KB and HepG2 cancer cells.

scholarly journals The Importance of Molecular Motion to Luminescence in Solid State

2020 ◽  
Author(s):  
Yujie Tu ◽  
Junkai Liu ◽  
Xuepeng Zhang ◽  
Tsz Shing Cheung ◽  
Xuewen He ◽  
...  
Keyword(s):  
Solid State ◽  
Photothermal Therapy ◽  
Room Temperature ◽  
Molecular Motion ◽  
Molecular Design ◽  
Acid Group ◽  
Carboxylic Acid Group ◽  
Room Temperature Phosphorescence ◽  
Model Compounds ◽  
Substituted Benzoic Acids

<div>Molecular motion is often considered detrimental to luminescence because it favors nonradiative decay. However, nothing is absolute, and molecular motion can also do useful work if utilized properly. For example, photothermal therapy makes use of the heat generated in light irradiation for cancer treatment. To further explore the merits of molecular motion, ortho-substituted benzoic acids were used as model compounds to evaluate the importance of molecular motion to luminescence in the solid state. It is verified that the twisting of the carboxylic acid group can activate spin vibronic coupling to facilitate intersystem crossing to result in more efficient room temperature phosphorescence (RTP). A five-state model is established to understand the ISC process and an effective pre-twisted molecular design strategy is put forward for the development of efficient RTP materials.</div>

scholarly journals Assembling nanotubes with cyclic peptoids

2014 ◽  
Vol 70 (a1) ◽  
pp. C563-C563
Author(s):  
Consiglia Tedesco ◽  
Irene Izzo ◽  
Francesco De Riccardis ◽  
Gavin Vaughan ◽  
Michela Brunelli ◽  
...  
Keyword(s):  
Solid State ◽  
Hydrogen Bonds ◽  
Biological Activities ◽  
Variable Temperature ◽  
Chemical Properties ◽  
Functional Materials ◽  
Building Blocks ◽  
Amide Proton ◽  
Side Chains ◽  
Peptide Backbone

Cyclic alpha-peptoids hold the attention of both synthetic and supramolecular chemists for their biostability and potential diversity but also for their elegant and intriguing architectures.[1] Peptoids differ from peptides in the side chains, which are shifted by one position along the peptide backbone to the nitrogen atom to give N-substituted oligoglycine. The lack of the amide proton prevents the formation of NH···OC hydrogen bonds and weaker interactions, as CH···OC hydrogen bonds and CH-pi interactions, play a key role. Inter-annular CH···OC hydrogen bonds can provide face to face or side by side arrangement of macrocycles mimicking beta-sheet secondary structure in proteins.[2] In particular, the role of side chains in the solid state assembly of peptoid macrocycles will be discussed to show how they can promote the formation of a peptoid nanotube by acting as pillars, extending vertically with respect to the macrocycle planes. [3] Examples of the solid state assembly of free and metallated cyclic peptoids will be reported to show their extreme versatility as building blocks for designing new materials, with novel chemical properties and defined biological activities. In particular the first crystal structure of a recently synthesized novel cyclic alpha-peptoid, containing open channels with a radius of approximately 7 Å, will be discussed as a case of the successful engineering of cyclopeptoid crystals. In figure it is shown the channel void surface as seen along the a axis (0.0003 au, CrystalExplorer 3.1). The results of recent variable temperature high resolution XRPD measurements performed at ESRF beamline ID31 will be also reported to highlight the unusual thermal stability of this class of compounds and how the mobility of the side chains may be exploited to prepare new functional materials. EU FP7-People- IRSES grant number 319011 is gratefully acknowledged.

scholarly journals The Importance of Solid-state Molecular Motion to Luminescence in Solid State

2020 ◽  
Author(s):  
Yujie Tu ◽  
Junkai Liu ◽  
Xuepeng Zhang ◽  
Tsz Shing Cheung ◽  
Xuewen He ◽  
...  
Keyword(s):  
Solid State ◽  
Photothermal Therapy ◽  
Room Temperature ◽  
Molecular Motion ◽  
Molecular Design ◽  
Acid Group ◽  
Carboxylic Acid Group ◽  
Room Temperature Phosphorescence ◽  
Model Compounds ◽  
Substituted Benzoic Acids

<div>Molecular motion is often considered detrimental to luminescence because it favors nonradiative decay. However, nothing is absolute, and molecular motion can also do useful work if utilized properly. For example, photothermal therapy makes use of the heat generated in light irradiation for cancer treatment. To further explore the merits of molecular motion, ortho-substituted benzoic acids were used as model compounds to evaluate the importance of molecular motion to luminescence in the solid state. It is verified that the twisting of the carboxylic acid group can activate spin vibronic coupling to facilitate intersystem crossing to result in more efficient room temperature phosphorescence (RTP). A five-state model is established to understand the ISC process and an effective pre-twisted molecular design strategy is put forward for the development of efficient RTP materials.</div>

scholarly journals The Importance of Solid-state Molecular Motion to Room Temperature Phosphorescence

2020 ◽  
Author(s):  
Yujie Tu ◽  
Junkai Liu ◽  
Xuepeng Zhang ◽  
Tsz Shing Cheung ◽  
Xuewen He ◽  
...  
Keyword(s):  
Solid State ◽  
Photothermal Therapy ◽  
Room Temperature ◽  
Molecular Motion ◽  
Molecular Design ◽  
Acid Group ◽  
Carboxylic Acid Group ◽  
Room Temperature Phosphorescence ◽  
Model Compounds ◽  
Substituted Benzoic Acids

<div>Molecular motion is often considered detrimental to luminescence because it favors nonradiative decay. However, nothing is absolute, and molecular motion can also do useful work if utilized properly. For example, photothermal therapy makes use of the heat generated in light irradiation for cancer treatment. To further explore the merits of molecular motion, ortho-substituted benzoic acids were used as model compounds to evaluate the importance of molecular motion to luminescence in the solid state. It is verified that the twisting of the carboxylic acid group can activate spin vibronic coupling to facilitate intersystem crossing to result in more efficient room temperature phosphorescence (RTP). A five-state model is established to understand the ISC process and an effective pre-twisted molecular design strategy is put forward for the development of efficient RTP materials.</div>

scholarly journals The Importance of Solid-state Molecular Motion to Room Temperature Phosphorescence

2020 ◽  
Author(s):  
Yujie Tu ◽  
Junkai Liu ◽  
Xuepeng Zhang ◽  
Tsz Shing Cheung ◽  
Xuewen He ◽  
...  
Keyword(s):  
Solid State ◽  
Photothermal Therapy ◽  
Room Temperature ◽  
Molecular Motion ◽  
Molecular Design ◽  
Acid Group ◽  
Carboxylic Acid Group ◽  
Room Temperature Phosphorescence ◽  
Model Compounds ◽  
Substituted Benzoic Acids

<div>Molecular motion is often considered detrimental to luminescence because it favors nonradiative decay. However, nothing is absolute, and molecular motion can also do useful work if utilized properly. For example, photothermal therapy makes use of the heat generated in light irradiation for cancer treatment. To further explore the merits of molecular motion, ortho-substituted benzoic acids were used as model compounds to evaluate the importance of molecular motion to luminescence in the solid state. It is verified that the twisting of the carboxylic acid group can activate spin vibronic coupling to facilitate intersystem crossing to result in more efficient room temperature phosphorescence (RTP). A five-state model is established to understand the ISC process and an effective pre-twisted molecular design strategy is put forward for the development of efficient RTP materials.</div>

A Novel Amino Acid Sequence-based Computational Approach to Predicting Cell-penetrating Peptides

2019 ◽  
Vol 15 (3) ◽  
pp. 206-211 ◽  
Author(s):  
Jihui Tang ◽  
Jie Ning ◽  
Xiaoyan Liu ◽  
Baoming Wu ◽  
Rongfeng Hu
Keyword(s):  
Machine Learning ◽  
Amino Acid ◽  
Amino Acid Position ◽  
Cell Penetrating Peptides ◽  
Support Vector ◽  
Cell Penetration ◽  
Drug Candidates ◽  
Machine Learning Model ◽  
Cell Penetrating ◽  
Novel Method

<P>Introduction: Machine Learning is a useful tool for the prediction of cell-penetration compounds as drug candidates. </P><P> Materials and Methods: In this study, we developed a novel method for predicting Cell-Penetrating Peptides (CPPs) membrane penetrating capability. For this, we used orthogonal encoding to encode amino acid and each amino acid position as one variable. Then a software of IBM spss modeler and a dataset including 533 CPPs, were used for model screening. </P><P> Results: The results indicated that the machine learning model of Support Vector Machine (SVM) was suitable for predicting membrane penetrating capability. For improvement, the three CPPs with the most longer lengths were used to predict CPPs. The penetration capability can be predicted with an accuracy of close to 95%. </P><P> Conclusion: All the results indicated that by using amino acid position as a variable can be a perspective method for predicting CPPs membrane penetrating capability.</P>

scholarly journals Fluorinated azobenzenes as supramolecular halogen-bonding building blocks

2019 ◽  
Vol 15 ◽  
pp. 2013-2019 ◽  
Author(s):  
Esther Nieland ◽  
Oliver Weingart ◽  
Bernd M Schmidt
Keyword(s):  
Solid State ◽  
Dft Calculations ◽  
Visible Light ◽  
Half Life ◽  
Photophysical Properties ◽  
Bathochromic Shift ◽  
Halogen Bonding ◽  
Building Blocks ◽  
Partial Overlap

ortho-Fluoroazobenzenes are a remarkable example of bistable photoswitches, addressable by visible light. Symmetrical, highly fluorinated azobenzenes bearing an iodine substituent in para-position were shown to be suitable supramolecular building blocks both in solution and in the solid state in combination with neutral halogen bonding acceptors, such as lutidines. Therefore, we investigate the photochemistry of a series of azobenzene photoswitches. Upon introduction of iodoethynyl groups, the halogen bonding donor properties are significantly strengthened in solution. However, the bathochromic shift of the π→π* band leads to a partial overlap with the n→π* band, making it slightly more difficult to address. The introduction of iodine substituents is furthermore accompanied with a diminishing thermal half-life. A series of three azobenzenes with different halogen bonding donor properties are discussed in relation to their changing photophysical properties, rationalized by DFT calculations.

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