Corrigendum to “Gas-phase ligand binding to Jacobsen's manganese salen catalyst: Functional group and steric effects” [Int. J. Mass Spectrom. 305 (2011) 40–44]

2012 ◽  
Vol 314 ◽  
pp. 63
Author(s):  
William C. Clodfelter ◽  
Emileigh M. Wong ◽  
Kelly A. Hay ◽  
Scott Gronert
Keyword(s):  
Ligand Binding ◽  
Gas Phase ◽  
Functional Group ◽  
Steric Effects ◽  
Mass Spectrom

Gas-phase ligand binding to Jacobsen's manganese salen catalyst: Functional group and steric effects

2011 ◽  
Vol 305 (1) ◽  
pp. 40-44 ◽  
Author(s):  
William C. Clodfelter ◽  
Emileigh H. Wong ◽  
Kelly A. Hay ◽  
Scott Gronert
Keyword(s):  
Ligand Binding ◽  
Gas Phase ◽  
Functional Group ◽  
Steric Effects

scholarly journals Functional Group Selective Derivatization and Gas-Phase Fragmentation Reactions of Plasmalogen Glycerophospholipids

2013 ◽  
Vol 2 (Special_Issue) ◽  
pp. S0015-S0015 ◽  
Author(s):  
Cassie J. Fhaner ◽  
Sichang Liu ◽  
Xiao Zhou ◽  
Gavin E. Reid
Keyword(s):  
Gas Phase ◽  
Functional Group ◽  
Fragmentation Reactions ◽  
Gas Phase Fragmentation

scholarly journals Functional Group Identification for FTIR Spectra Using Image-Based Machine Learning Models

2021 ◽  
Author(s):  
Abigail Enders ◽  
Nicole North ◽  
Chase Fensore ◽  
Juan Velez-Alvarez ◽  
Heather Allen
Keyword(s):  
Machine Learning ◽  
Gas Phase ◽  
Functional Groups ◽  
Functional Group ◽  
Spectroscopic Method ◽  
Group Identification ◽  
Spectroscopic Technique ◽  
Ftir Spectra ◽  
Spectral Interpretation ◽  
Time Required

<p>Fourier Transform Infrared Spectroscopy (FTIR) is a ubiquitous spectroscopic technique. Spectral interpretation is a time-consuming process, but it yields important information about functional groups present in compounds and in complex substances. We develop a generalizable model via a machine learning (ML) algorithm using Convolutional Neural Networks (CNNs) to identify the presence of functional groups in gas phase FTIR spectra. The ML models will reduce the amount of time required to analyze functional groups and facilitate interpretation of FTIR spectra. Through web scraping, we acquire intensity-frequency data from 8728 gas phase organic molecules within the NIST spectral database and transform the data into images. We successfully train models for 15 of the most common organic functional groups, which we then determine via identification from previously untrained spectra. These models serve to expand the application of FTIR measurements for facile analysis of organic samples. Our approach was done such that we have broad functional group models that inference in tandem to provide full interpretation of a spectrum. We present the first implementation of ML using image-based CNNs for predicting functional groups from a spectroscopic method.</p>

scholarly journals In Silico Investigation of Mitragynine and 7-Hydroxymitragynine Metabolism

2019 ◽  
Author(s):  
Taweetham Limpanuparb ◽  
Rattha Noorat ◽  
Yuthana Tantirungrotechai
Keyword(s):  
Gas Phase ◽  
In Silico ◽  
Metabolic Pathways ◽  
Experimental Studies ◽  
Medicinal Uses ◽  
Detection Techniques ◽  
Mass Spectrom ◽  
Gibbs Energies ◽  
In Silico Study

Abstract Objective: Mitragynine is the main active compound of Mitragyna speciose (Kratom in Thai). The understanding of mitragynine derivative metabolism in human body is required to develop effective detection techniques in case of drug abuse or establish an appropriate dosage in case of medicinal uses. This in silico study is based upon in vivo results in rat and human by Philipp et al. (J. Mass Spectrom., 2009, 44, 1249.) Results: The gas-phase structures of mitragynine, 7-hydroxymitragynine and their metabolites were obtained by quantum chemical method at B3LYP/6-311++G(d,p) level. Results in terms of standard Gibbs energies of reaction for all metabolic pathways are reported with solvation energy from SMD model. We found that 7-hydroxy substitution leads to changes in reactivity in comparison to mitragynine: position 17 is more reactive towards demethylation and conjugation to a glucuronide and position 9 is less reactive towards conjugation to a glucuronide. Despite the changes, position 9 is the most reactive for demethylation and position 17 is the most reactive for conjugation to a glucuronide for both mitragynine and 7-hydroxymitragynine. Our results suggest that 7-hydroxy substitution could lead to different metabolic pathways and raise an important question for further experimental studies of this more potent derivative.

Computational Determination of Heats of Formation of Energetic Compounds

1995 ◽  
Vol 418 ◽  
Author(s):  
Peter Politzer ◽  
Jane S. Murray ◽  
M. Edward Grice
Keyword(s):  
Gas Phase ◽  
Density Functional ◽  
Functional Group ◽  
Solid Phase ◽  
Heats Of Formation ◽  
Energetic Compounds ◽  
Phase Data ◽  
Heats Of Vaporization ◽  
Group Effects

AbstractA recently-developed density functional procedure for computing gas phase heats of formation is briefly described and results for several categories of energetic compounds are summarized and discussed. Liquid and solid phase values can be obtained by combining the gas phase data with heats of vaporization and sublimation estimated by means of other relationships. Some observed functional group effects upon heats of formation are noted.

scholarly journals Endogenous Binding of Steroid Molecules to DNA Nucleotides by a Ca2+/PO4- Process to Enable Gene Transcription

2020 ◽  
Author(s):  
Charles Schaper
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Ligand Binding ◽  
Gene Transcription ◽  
Functional Group ◽  
Ring Structure ◽  
Binding Domain ◽  
Ligand Binding Domain ◽  
Steroid Molecule ◽  
First Time

Steroid hormones, such as cortisol, testosterone and estrogen, have powerful control over human physiology, growth, and reproduction, but efforts to deploy its potential, such as with glucocorticoids, a first-line defense of inflammation, are often met with severe side effects. Unfortunately, much is unknown about the basic interaction of steroid molecules with DNA, including its receptors, activators, factors, and the gene transcription procedure. In this research article, a remarkable finding is shown for the first time, in which it is illustrated through structural analysis that the base pairings of the four DNA nucleotides, adenine with thymine (A-T) and cytosine with guanine (C-G), form perfectly the classic four ring structure of the steroid molecule, which indicates the profound result put forth in this article that steroid molecules bind directly to DNA for the purpose of gene transcription. Further, critical to a basic understanding of DNA, it is resolved here of the location of the unusual ``missing" hydrogen bond of the A-T pairing, which has only two internal hydrogen bonds whereas C-G has three hydrogen bonds. It is shown that the third hydrogen bond for A-T is formed when the A-T nucleotide is coupled with corticosteroids, such as cortisol, which has an oxygen functional group that is perfectly positioned to form a hydrogen bond with the accessible oxygen-based functional group of thymine. In addition, to facilitate the binding process, it is shown that Ca2+ ions, which are associated with the ligand binding domain of the steroid receptor prior to its association with DNA, couple the oxygen-based functional groups at each end of the steroid molecule with the PO4- ions of adjacent nucleotides and thus bind the steroid molecule directly to the nucleic acid. The results are further amplified by analysis of the cortisol hormone and the ligand binding domain of the glucocorticoid receptor in its interaction with the A-T nucleotide pairing.

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