scholarly journals DP4-AI Automated NMR Data Analysis: Straight from Spectrometer to Structure

2020 ◽  
Author(s):  
Alexander Howarth ◽  
Kristaps Ermanis ◽  
Jonathan Goodman
Keyword(s):  
1H Nmr ◽  
Open Source Software ◽  
Processing Speed ◽  
Structure Elucidation ◽  
Structural Information ◽  
Fold Increase ◽  
Structural Uncertainty ◽  
Large Sets ◽  
Nmr Data ◽  
Objective Model

<div> <p>A robust system for automatic processing and assignment of raw 13C and 1H NMR data DP4-AI has been developed and integrated into our computational organic molecule structure elucidation workflow. Starting from a molecular structure with undefined stereochemistry or other structural uncertainty, this system allows for completely automated structure elucidation. Methods for NMR peak picking using objective model selection and algorithms for matching the calculated 13C and 1H NMR shifts to peaks in noisy experimental NMR data were developed. DP4-AI achieved a 60-fold increase in processing speed, and near-elimination of the need for scientist time, when rigorously evaluated used a challenging test set of molecules. DP4-AI represents a leap forward in NMR structure elucidation and a step-change in the functionality of DP4. It enables high-throughput analyses of databases and large sets of molecules, which were previously impossible, and paves the way for the discovery of new structural information through machine learning. This new functionality has been coupled with an intuitive GUI and is available as open-source software at https://github.com/KristapsE/DP4-AI.</p> </div> <br>

scholarly journals DP4-AI Automated NMR Data Analysis: Straight from Spectrometer to Structure

2020 ◽  
Author(s):  
Alexander Howarth ◽  
Kristaps Ermanis ◽  
Jonathan Goodman
Keyword(s):  
1H Nmr ◽  
Open Source Software ◽  
Processing Speed ◽  
Structure Elucidation ◽  
Structural Information ◽  
Fold Increase ◽  
Structural Uncertainty ◽  
Large Sets ◽  
Nmr Data ◽  
Objective Model

<div> <p>A robust system for automatic processing and assignment of raw 13C and 1H NMR data DP4-AI has been developed and integrated into our computational organic molecule structure elucidation workflow. Starting from a molecular structure with undefined stereochemistry or other structural uncertainty, this system allows for completely automated structure elucidation. Methods for NMR peak picking using objective model selection and algorithms for matching the calculated 13C and 1H NMR shifts to peaks in noisy experimental NMR data were developed. DP4-AI achieved a 60-fold increase in processing speed, and near-elimination of the need for scientist time, when rigorously evaluated used a challenging test set of molecules. DP4-AI represents a leap forward in NMR structure elucidation and a step-change in the functionality of DP4. It enables high-throughput analyses of databases and large sets of molecules, which were previously impossible, and paves the way for the discovery of new structural information through machine learning. This new functionality has been coupled with an intuitive GUI and is available as open-source software at https://github.com/KristapsE/DP4-AI.</p> </div> <br>

scholarly journals Isolation of Khusimol from the Root of Vetiver (Vetiveria zizanioides L. Nash) Grown in Samarang – Garut and the Study of its Profile after Harvesting

2021 ◽  
Vol 11 (2) ◽  
pp. 3549-3559
Keyword(s):  
Essential Oil ◽  
1H Nmr ◽  
Column Chromatography ◽  
13C Nmr ◽  
Structure Elucidation ◽  
Molecular Formula ◽  
Harvest Time ◽  
Target Compound ◽  
Vetiveria Zizanioides ◽  
Nmr Data

Vetiver oil is a type of essential oil extracted from the vetiver plant's roots. Vetiver oil is commonly used as a major odor contributor in the fragrance and aromatherapy industry. This study aimed to isolation khusimol compound from vetiver oil, which will be used as a marker and determine khusimol content in various drying times after harvesting. The target compound was found in the combination of fraction 3 (GF-3). Furthermore, GF-3 was subfractionated by classical column chromatography. Structure elucidation of isolate X was performed by NMR. 1H-NMR and 13C-NMR data of isolate X as the same as 1H-NMR and 13C-NMR data of khusimol compound in literature. Molecular formula of khusimol C15H24O. Khusimol content in extract with various drying times after harvest time 0 hr, 6 hr, 12 hr, 24 hr, 36 hr and 48 hr were 1.95 ± 0.02; 2.15 ± 0.02; 2.30 ± 0.03; 2.81 ± 0.01; 1.72 ± 0.03 and 1.38 ± 0.02 mg/100 g. The odor contributor compound was khusimol (C15H24O). The highest khusimol content was revealed by vetiver extract, which drying for 24 hr after harvest. Drying vetiver more than 24 hr could reduce khusimol content.

Unexpected Keto-enol Tautomerism in the Cyclopyridinophane Class Direct and indirect proofs

2008 ◽  
Vol 59 (10) ◽  
Author(s):  
Paul Ionut Dron ◽  
Neculai Doru Miron ◽  
Gheorghe Surpateanu
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
Stable Conformer ◽  
Ph Measurements ◽  
Theoretical Methods ◽  
Nmr Data ◽  
Tautomeric Forms ◽  
New Compounds

The paper presents the synthesis of cyclo (bis-paraquat p-phenylene p-phenylene-carbonyl) tetrakis (hexafluorophosphate), named �CETOBOX�, and the closely related structural determinations. This compound exists in three tautomeric forms. These forms were evidentiated by NMR-data (1H-NMR, TOCSY, COSY, NOESY), UV-Vis spectra coupled with pH measurements and by synthesis. As the �CETOBOX� gives �in situ� only the corresponding monoylide, the synthesis of a new fluorescent indolizine cyclophane has been performed by a 3+2 cycloaddition. All structures of the new compounds presented herein have been established by NMR spectroscopy. Also, theoretical methods (MM3, AM1, AM1-COSMO and B88LYPDFT) have been used to determine the most stable conformer structures.

scholarly journals Database Independent Automated Structure Elucidation of Organic Molecules Based on IR, 1H NMR, 13C NMR, and MS Data

2020 ◽  
Author(s):  
Matevž Pesek ◽  
Andraž Juvan ◽  
Jure Jakoš ◽  
Janez Košmrlj ◽  
Matija Marolt ◽  
...  
Keyword(s):  
1H Nmr ◽  
13C Nmr ◽  
Structure Elucidation ◽  
Organic Molecules

Synthesis and 1H NMR data assignment of 3-acetamido-4-amino-3,4-dihydro-2H-pyran-6-carboxylates and their acetyl-migrated isomers

2021 ◽  
pp. 1-9
Author(s):  
Chuanqi Duan ◽  
Weiyuan Liu ◽  
Liang Chen ◽  
Jing Pan ◽  
Yubin Liu ◽  
...  
Keyword(s):  
1H Nmr ◽  
Nmr Data

scholarly journals Structure Elucidation of an Pentacyclic Triterpenoid and Phenolic from Steam Bark of Vitex Pubescens Vahl

2019 ◽  
Vol 1 (1) ◽  
pp. 68-74
Author(s):  
Lenny Anwar
Keyword(s):  
1H Nmr ◽  
13C Nmr ◽  
Betulinic Acid ◽  
Spectroscopic Data ◽  
Structure Elucidation ◽  
Stem Bark ◽  
Hydroxybenzoic Acid ◽  
Pentacyclic Triterpenoid ◽  
Reported Data ◽  
First Time

Pentacyclic triterpenoid, betulinic acid (1) and phenolic, p-hydroxybenzoic acid (2), had been isolated for the first time from the stem bark of Vitex pubescens Vahl. The structure of compounds 1 and 2 was determined based on the interpretation of spectroscopic data including UV, IR, NMR (1H-NMR, 13C-NMR, HMQC, HMBC, COSY) and MS, as well as by comparison with those reported data.

scholarly journals Water soluble metal-polymeric complexes of gallium and triple co-polymer of N-vinylpyrrolidone with N-vinylformamide and N-vinylminodiacetic acid

2019 ◽  
Vol 485 (3) ◽  
pp. 306-310
Author(s):  
N. I. Gorshkov ◽  
A. Yu. Murko ◽  
I. I. Gavrilova ◽  
I. I. Malakhova ◽  
V. D. Krasikov ◽  
...  
Keyword(s):  
Molecular Weight ◽  
1H Nmr ◽  
Metal Ion ◽  
Water Soluble ◽  
Polymer Complex ◽  
Nmr Data ◽  
Exclusion Chromatography ◽  
Polymeric Complexes ◽  
Metal Polymer

A terpolymer with a molecular weight of 45 kDa containing 7 mol.% of vinylamine units, 80 mol.% of vinylpyrrolidone, and 3 mol.% of vinyliminodiacetic acid units has been synthesized. Its complexation with Ga3+ ion has been studied by HPLC. The resulting metal–polymer complex has been characterized by exclusion chromatography and spectral (IR, 1H NMR) data. The complex has a monomolecular structure where the metal ion acts as an anchor fragment between vinyliminodiacetic acid units and is stable in the reaction of interligand exchange with histidine.

scholarly journals SYNTHESIS OF SECONDARY ALCOHOL COMPOUNDS FROM SAFROLE AND METHYLEUGENOL

2010 ◽  
Vol 3 (3) ◽  
pp. 176-178
Author(s):  
Hanoch J Sohilait ◽  
Hardjono Sastrohamidjojo ◽  
Sabirin Matsjeh
Keyword(s):  
1H Nmr ◽  
Sodium Borohydride ◽  
13C Nmr ◽  
Structure Elucidation ◽  
Mercuric Acetate ◽  
Secondary Alcohol ◽  
Secondary Alcohols ◽  
In Situ Reduction

Synthesis of secondary alcohols compound from safrole and methyleugenol has been achieved through conversion of allyl group to alcohol.The reaction of safrole and methyleugenol with mercuric acetate in aqueous tetrahydrofuran, followed by in situ reduction of the mercurial intermediate by alkaline sodium borohydride produced secondary alcohol namely safryl alcohol (71.25%) and methyleugenil alcohol (65.56%). The structure elucidation of these products were analyzed by FTIR, 1H-NMR, 13C-NMR and MS.   Keywords: Secondary alcohols; safrole; methyleugenol

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