scholarly journals Imbalance-Based Irregularity Molecular Descriptors of Nanostar Dendrimers

Processes ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 517 ◽  
Author(s):  
Zafar Hussain ◽  
Mobeen Munir ◽  
Shazia Rafique ◽  
Tayyab Hussnain ◽  
Haseeb Ahmad ◽  
...  
Keyword(s):  
Structural Properties ◽  
Molecular Descriptors ◽  
Graphical Analysis ◽  
Central Core ◽  
Molecular Topology ◽  
Molecular Graphs ◽  
Enthalpy And Entropy

Dendrimers are branched organic macromolecules with successive layers of branch units surrounding a central core. The molecular topology and the irregularity of their structure plays a central role in determining structural properties like enthalpy and entropy. Irregularity indices which are based on the imbalance of edges are determined for the molecular graphs associated with some general classes of dendrimers. We also provide graphical analysis of these indices for the above said classes of dendrimers.

scholarly journals Bounds of Degree-Based Molecular Descriptors for Generalized F -sum Graphs

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Jia Bao Liu ◽  
Sana Akram ◽  
Muhammad Javaid ◽  
Abdul Raheem ◽  
Roslan Hasni
Keyword(s):  
Structural Properties ◽  
Electron Energy ◽  
Boiling Point ◽  
Molecular Descriptors ◽  
Molecular Descriptor ◽  
Molecular Graph ◽  
Topological Indices ◽  
Real Numbers ◽  
Molecular Graphs

A molecular descriptor is a mathematical measure that associates a molecular graph with some real numbers and predicts the various biological, chemical, and structural properties of the underlying molecular graph. Wiener (1947) and Trinjastic and Gutman (1972) used molecular descriptors to find the boiling point of paraffin and total π -electron energy of the molecules, respectively. For molecular graphs, the general sum-connectivity and general Randić are well-studied fundamental topological indices (TIs) which are considered as degree-based molecular descriptors. In this paper, we obtain the bounds of the aforesaid TIs for the generalized F -sum graphs. The foresaid TIs are also obtained for some particular classes of the generalized F -sum graphs as the consequences of the obtained results. At the end, 3   D -graphical presentations are also included to illustrate the results for better understanding.

Molecular Topology and Other Promiscuity Determinants as Predictors of Therapeutic Class - A Theoretical Framework to Guide Drug Repositioning?

2018 ◽  
Vol 18 (13) ◽  
pp. 1110-1122 ◽  
Author(s):  
Juan F. Morales ◽  
Lucas N. Alberca ◽  
Sara Chuguransky ◽  
Mauricio E. Di Ianni ◽  
Alan Talevi ◽  
...  
Keyword(s):  
Molecular Descriptors ◽  
Drug Repositioning ◽  
Drug Repurposing ◽  
Topological Descriptors ◽  
Log P ◽  
Acidity Constant ◽  
Molecular Topology ◽  
Clustering Methods ◽  
Mean Values ◽  
Qsar Models

Much interest has been paid in the last decade on molecular predictors of promiscuity, including molecular weight, log P, molecular complexity, acidity constant and molecular topology, with correlations between promiscuity and those descriptors seemingly being context-dependent. It has been observed that certain therapeutic categories (e.g. mood disorders therapies) display a tendency to include multi-target agents (i.e. selective non-selectivity). Numerous QSAR models based on topological descriptors suggest that the topology of a given drug could be used to infer its therapeutic applications. Here, we have used descriptive statistics to explore the distribution of molecular topology descriptors and other promiscuity predictors across different therapeutic categories. Working with the publicly available ChEMBL database and 14 molecular descriptors, both hierarchical and non-hierchical clustering methods were applied to the descriptors mean values of the therapeutic categories after the refinement of the database (770 drugs grouped into 34 therapeutic categories). On the other hand, another publicly available database (repoDB) was used to retrieve cases of clinically-approved drug repositioning examples that could be classified into the therapeutic categories considered by the aforementioned clusters (111 cases), and the correspondence between the two studies was evaluated. Interestingly, a 3- cluster hierarchical clustering scheme based on only 14 molecular descriptors linked to promiscuity seem to explain up to 82.9% of approved cases of drug repurposing retrieved of repoDB. Therapeutic categories seem to display distinctive molecular patterns, which could be used as a basis for drug screening and drug design campaigns, and to unveil drug repurposing opportunities between particular therapeutic categories.

Higher-Order and Mixed Discrete Derivatives such as a Novel Graph- Theoretical Invariant for Generating New Molecular Descriptors

2019 ◽  
Vol 19 (11) ◽  
pp. 944-956 ◽  
Author(s):  
Oscar Martínez-Santiago ◽  
Yovani Marrero-Ponce ◽  
Ricardo Vivas-Reyes ◽  
Mauricio E.O. Ugarriza ◽  
Elízabeth Hurtado-Rodríguez ◽  
...  
Keyword(s):  
Molecular Descriptors ◽  
3D Qsar ◽  
Higher Order ◽  
Molecular Structures ◽  
Qsar Modeling ◽  
Statistical Parameters ◽  
Molecular Graphs ◽  
New Family ◽  
Mixed Derivatives ◽  
Discrete Derivative

Background: Recently, some authors have defined new molecular descriptors (MDs) based on the use of the Graph Discrete Derivative, known as Graph Derivative Indices (GDI). This new approach about discrete derivatives over various elements from a graph takes as outset the formation of subgraphs. Previously, these definitions were extended into the chemical context (N-tuples) and interpreted in structural/physicalchemical terms as well as applied into the description of several endpoints, with good results. Objective: A generalization of GDIs using the definitions of Higher Order and Mixed Derivative for molecular graphs is proposed as a generalization of the previous works, allowing the generation of a new family of MDs. Methods: An extension of the previously defined GDIs is presented, and for this purpose, the concept of Higher Order Derivatives and Mixed Derivatives is introduced. These novel approaches to obtaining MDs based on the concepts of discrete derivatives (finite difference) of the molecular graphs use the elements of the hypermatrices conceived from 12 different ways (12 events) of fragmenting the molecular structures. The result of applying the higher order and mixed GDIs over any molecular structure allows finding Local Vertex Invariants (LOVIs) for atom-pairs, for atoms-pairs-pairs and so on. All new families of GDIs are implemented in a computational software denominated DIVATI (acronym for Discrete DeriVAtive Type Indices), a module of KeysFinder Framework in TOMOCOMD-CARDD system. Results: QSAR modeling of the biological activity (Log 1/K) of 31 steroids reveals that the GDIs obtained using the higher order and mixed GDIs approaches yield slightly higher performance compared to previously reported approaches based on the duplex, triplex and quadruplex matrix. In fact, the statistical parameters for models obtained with the higher-order and mixed GDI method are superior to those reported in the literature by using other 0-3D QSAR methods. Conclusion: It can be suggested that the higher-order and mixed GDIs, appear as a promissory tool in QSAR/QSPRs, similarity/dissimilarity analysis and virtual screening studies.

Über topologische Räume, welche kovalenten Verbindungen zugeordnet werden können, und ihre Bedeutung für die Chemie

1986 ◽  
Vol 41 (3) ◽  
pp. 560-566
Author(s):  
Oskar E. Polansky
Keyword(s):  
Topological Charge ◽  
Chemical Structure ◽  
Topological Spaces ◽  
Molecular Topology ◽  
Molecular Graphs ◽  
Topological Effect ◽  
Charge Stabilization

Using Hausdorff’s neighbourhood axioms, topological spaces associated with molecular graphs are derived. Their meaning for chemistry is illustrated by topological charge stabilization and the topological effect on MO (TEMO). Finally the role of molecular topology with regard to chemical structure is discussed.

Molecular topology. VIII: Centricities in molecular graphs. The mollen algorithm

1992 ◽  
Vol 11 (1) ◽  
pp. 259-270 ◽  
Author(s):  
M. V. Diudea ◽  
D. Horvath ◽  
I. E. Kacso ◽  
O. M. Minailiuc ◽  
B. Parv
Keyword(s):  
Molecular Topology ◽  
Molecular Graphs

scholarly journals Irregular topological indices of certain metal organic frameworks

2020 ◽  
Vol 44 (1) ◽  
pp. 73-81
Author(s):  
Yu-Ming Chu ◽  
Muhammad Abid ◽  
Muhammad Imran Qureshi ◽  
Asfand Fahad ◽  
Adnan Aslam
Keyword(s):  
Physicochemical Property ◽  
Metal Organic Frameworks ◽  
Topological Indices ◽  
Butylated Hydroxytoluene ◽  
Molecular Topology ◽  
Metal Organic ◽  
Enthalpy And Entropy ◽  
Relationship Of

Abstract It is interesting to study the molecular topology that provides a base for relationship of physicochemical property of a definite molecule. The topology of a molecule and the irregularity of the structure plays a vital character in shaping properties of the structure like enthalpy and entropy. In this article, we are interested to calculate some irregular topological indices of two classes of metal organic frameworks (MOFs) namely BHT (Butylated hydroxytoluene) based metal (M = Co, Fe, Mn, Cr) organic frameworks (MBHT) and M1TPyP-M2 (TPyP = 5, 10, 15, 20-tetrakis (4-pyridyl) porphyrin and M1, M2, = Fe and Co) MOFs. Also we compare our results graphically.

scholarly journals Banhatti, revan and hyper-indices of silicon carbide Si2C3-III[n,m]

2021 ◽  
Vol 19 (1) ◽  
pp. 646-652
Author(s):  
Dongming Zhao ◽  
Manzoor Ahmad Zahid ◽  
Rida Irfan ◽  
Misbah Arshad ◽  
Asfand Fahad ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Graph Theory ◽  
Topological Index ◽  
Molecular Graph ◽  
Graphical Analysis ◽  
Topological Indices ◽  
Chemical Bonds ◽  
Chemical Graph ◽  
Molecular Graphs ◽  
Chemical Graph Theory

Abstract In recent years, several structure-based properties of the molecular graphs are understood through the chemical graph theory. The molecular graph G G of a molecule consists of vertices and edges, where vertices represent the atoms in a molecule and edges represent the chemical bonds between these atoms. A numerical quantity that gives information related to the topology of the molecular graphs is called a topological index. Several topological indices, contributing to chemical graph theory, have been defined and vastly studied. Recent inclusions in the class of the topological indices are the K-Banhatti indices. In this paper, we established the precise formulas for the first and second K-Banhatti, modified K-Banhatti, K-hyper Banhatti, and hyper Revan indices of silicon carbide Si 2 C 3 {{\rm{Si}}}_{2}{{\rm{C}}}_{3} - III [ n , m ] {\rm{III}}\left[n,m] . In addition, we present the graphical analysis along with the comparison of these indices for Si 2 C 3 {{\rm{Si}}}_{2}{{\rm{C}}}_{3} - III [ n , m ] {\rm{III}}\left[n,m] .

The Influence of γ-Irradiation on the Structure and Properties of the Cu-11.5 wt. % Al-4 wt. % Ni Shape Memory Alloys

2013 ◽  
Vol 845 ◽  
pp. 128-132
Author(s):  
Safaa N. Saud ◽  
Esah Hamzah ◽  
T. Abubakar ◽  
Azadeh Refaei ◽  
Raheleh Hosseinian
Keyword(s):  
Phase Transformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Structural Properties ◽  
Room Temperature ◽  
Structure And Properties ◽  
Γ Irradiation ◽  
Transformation Temperatures ◽  
Enthalpy And Entropy ◽  
Complex Influence

This study investigated the influence of 60Co-γ-irradiation on the structure and properties of Cu-Al-Ni shape memory alloys. The phase transformation temperatures were evaluated by differential scanning calorimeter (DSC). It was found that the γ-irradiation had a complex influence on the phase transformation parameters of Cu-Al-Ni SMAs. However, the transformation temperatures were shifted and a new curve was obtained after exposure to different irradiation doses. The thermodynamic parameters such as enthalpy and entropy tended to increase/decrease depending on the amount of the exposure. The structural properties of the exposed samples were studied by using optical microscopy and hardness measurements at room temperature. It was also found that the structural-properties of the Cu-Al-Ni SMAs were completely affected by the amount of the applied γ-irradiation dose.

scholarly journals Computational Analysis of new Degree-based descriptors of oxide networks

2019 ◽  
Vol 17 (1) ◽  
pp. 177-182 ◽  
Author(s):  
Zafar Hussain ◽  
Mobeen Munir ◽  
Muhammad Bilal ◽  
Alam Ameer ◽  
Shazia Rafique ◽  
...  
Keyword(s):  
Computational Analysis ◽  
Graphical Analysis ◽  
Topological Indices ◽  
Zagreb Index ◽  
Zagreb Indices ◽  
Molecular Graphs ◽  
Pharmaceutical Industries ◽  
Forgotten Index

AbstractOxide networks have diverse applications in the polymer and pharmaceutical industries. Polynomials and degree-based topological indices have tendencies to correlate properties of molecular graphs. In this article, we formulate the closed forms of Zagreb and forgotten polynomials and topological indices such as Hyper-Zagreb index, first and second multiple Zagreb indices, forgotten index, Albert index, Bell index, IRM(G) of oxide networks. We also compute the F-index of complement of oxide networks, F-coindex of G and F-coindex of complement of oxide networks. We put graphical analysis of each index with respect to the parameter involved in each case.

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