Polyhydroxyalkanoate quantification in organic wastes and pure cultures using a single-step extraction and 1H NMR analysis

2012 ◽  
Vol 66 (5) ◽  
pp. 1000-1006 ◽  
Author(s):  
Elisabeth Linton ◽  
Asif Rahman ◽  
Sridhar Viamajala ◽  
Ronald C. Sims ◽  
Charles D. Miller
Keyword(s):  
1H Nmr ◽  
Azotobacter Vinelandii ◽  
Nile Blue ◽  
Agricultural Waste ◽  
Accurate Method ◽  
Single Step ◽  
Proton Nuclear Magnetic Resonance ◽  
Copolymer Composition ◽  
Nmr Analysis ◽  
Nmr Method

In this study, a proton nuclear magnetic resonance (1H NMR) method was developed to quantitatively analyze polyhydroxyalkanoate (PHA) content in Cupriavidus necator H16, Azotobacter vinelandii AvOP, and mixed microbial cultures from the effluent of an agricultural waste treatment anaerobic digester. In contrast to previous methods, a single-step PHA extractive method using deuterated chloroform was established, thereby facilitating direct 1H NMR analysis. The accuracy of the method was verified through comparison with well-established gas chromatography (GC) methanolysis techniques. Nile blue fluorescence staining was also carried out to serve as an independent and qualitative indicator of intracellular PHA content. The results indicate that the 1H NMR method is appropriate for rapid and non-destructive quantification of overall PHA content and determination of PHA copolymer composition in a variety of cultures. Notably, this technique was effective in measuring PHA content in full-strength waste samples where high concentrations of background impurities and organic compounds are present. The straightforward procedures minimize error-introducing steps, require less time and materials, and result in an accurate method suitable for routine analyses.

scholarly journals Enantiomeric Variability of Distaminolyne A. Refinement of ECD and NMR Methods for Determining Optical Purity of 1-Amino-2-Alkanols

Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 90 ◽  
Author(s):  
A. Pearce ◽  
Brent Copp ◽  
Tadeusz Molinski
Keyword(s):  
New Zealand ◽  
1H Nmr ◽  
Geographic Distribution ◽  
Optical Purity ◽  
Nmr Analysis ◽  
Improved Method ◽  
Chiral Reagent ◽  
Nmr Method ◽  
Nmr Methods ◽  
Derivatives Of

Sample configurations of distaminolyne A (1a); isolated from the ascidians Pseudodistoma opacum and P. cereum, and collected at different sites in New Zealand, were investigated by two methods: Exciton coupled electronic circular dichroism (EC ECD) of the corresponding N,O-dibenzoyl derivative 1b; and chiral reagent derivatization of 1a with (S)- and (R)-α-methoxyphenylacetic acid (MPA), followed by 1H-NMR analysis. Configuration and optical purity of 1a (%ee) was found to vary depending on the geographic distribution of ascidian colonies. An improved method for preparing N,O-diarenoyl derivatives of 1a was optimized. The EC ECD method was found to be complementary to the MPA-NMR method at different ranges of %ee.

scholarly journals A Rapid and Feasible 1H-NMR Quantification Method of Ephedrine Alkaloids in Ephedra Herbal Preparations

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1599
Author(s):  
Hsin-Yi Hung ◽  
Shih-Min Lin ◽  
Chia-Ying Li ◽  
Sio-Hong Lam ◽  
Yu-Yi Chan ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
1H Nmr ◽  
Present Method ◽  
Internal Standard ◽  
Proton Nuclear Magnetic Resonance ◽  
Nmr Spectrum ◽  
Herbal Preparations ◽  
Nmr Method ◽  
Quantification Method ◽  
Preliminary Purification

A highly specific and sensitive proton nuclear magnetic resonance (1H-NMR) method has been developed for the quantification of ephedrine alkaloid derivatives in Ephedra herbal commercial prescriptions. At the region of δ 4.0 to 5.0 ppm in the 1H NMR spectrum, the characteristic signals are separated well from each other, and six analogues in total, methylephedrine (ME), ephedrine (EP), norephedrine (NE), norpseudoephedrine (NP), pseudoephedrine (PE), and methylpseudoephedrine (MP) could be identified. The quantities of these compounds are calculated by the relative ratio of the integral values of the target peak for each compound to the known concentrations of the internal standard anthracene. The present method allows for a rapid and simple quantification of ephedrine alkaloid derivatives in Ephedra-related commercial prescriptions without any preliminary purification steps and standard compounds, and accordingly it can be a powerful tool to verify different Ephedra species. In comparison to conventional chromatographic methods, the advantages of this method include the fact that no standard compounds are required, the quantification can be directly performed on the crude extracts, a better selectivity for various ephedrine alkaloid derivatives, and the fact that a very significant time-gain may be achieved.

scholarly journals Neuroendocrine Neoplasms: Identification of Novel Metabolic Circuits of Potential Diagnostic Utility

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 374
Author(s):  
Beatriz Jiménez ◽  
Mei Ran Abellona U ◽  
Panagiotis Drymousis ◽  
Michael Kyriakides ◽  
Ashley K. Clift ◽  
...  
Keyword(s):  
1H Nmr ◽  
Cancer Metabolism ◽  
Proton Nuclear Magnetic Resonance ◽  
Neuroendocrine Neoplasms ◽  
Resonance Spectroscopy ◽  
Diagnostic Utility ◽  
Signalling Molecules ◽  
Prognostic Accuracy ◽  
Diagnostic Potential ◽  
Healthy Control

The incidence of neuroendocrine neoplasms (NEN) is increasing, but established biomarkers have poor diagnostic and prognostic accuracy. Here, we aim to define the systemic metabolic consequences of NEN and to establish the diagnostic utility of proton nuclear magnetic resonance spectroscopy (1H-NMR) for NEN in a prospective cohort of patients through a single-centre, prospective controlled observational study. Urine samples of 34 treatment-naïve NEN patients (median age: 59.3 years, range: 36–85): 18 had pancreatic (Pan) NEN, of which seven were functioning; 16 had small bowel (SB) NEN; 20 age- and sex-matched healthy control individuals were analysed using a 600 MHz Bruker 1H-NMR spectrometer. Orthogonal partial-least-squares-discriminant analysis models were able to discriminate both PanNEN and SBNEN patients from healthy control (Healthy vs. PanNEN: AUC = 0.90, Healthy vs. SBNEN: AUC = 0.90). Secondary metabolites of tryptophan, such as trigonelline and a niacin-related metabolite were also identified to be universally decreased in NEN patients, while upstream metabolites, such as kynurenine, were elevated in SBNEN. Hippurate, a gut-derived metabolite, was reduced in all patients, whereas other gut microbial co-metabolites, trimethylamine-N-oxide, 4-hydroxyphenylacetate and phenylacetylglutamine, were elevated in those with SBNEN. These findings suggest the existence of a new systems-based neuroendocrine circuit, regulated in part by cancer metabolism, neuroendocrine signalling molecules and gut microbial co-metabolism. Metabonomic profiling of NEN has diagnostic potential and could be used for discovering biomarkers for these tumours. These preliminary data require confirmation in a larger cohort.

scholarly journals Vapor Phase Modification for Selective Enrichment of Grafted Styrene/Acrylonitrile onto Carbon Nanotubes Via ATRP

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 459
Author(s):  
Maryam Azadbakht ◽  
Elnaz Esmizadeh ◽  
Ali Vahidifar ◽  
Tizazu H. Mekonnen ◽  
Mehdi Salami-Kalajahi
Keyword(s):  
Carbon Nanotubes ◽  
1H Nmr ◽  
Vapor Phase ◽  
Proton Nuclear Magnetic Resonance ◽  
Acid Vapor ◽  
Selective Enrichment ◽  
Pristine Mwcnts ◽  
Morphological Studies ◽  
Phase Oxidation ◽  
Multi Walled Carbon Nanotubes

Nitric acid vapor phase oxidation of multi-walled carbon nanotubes (MWCNTs) was proposed as a promising technique to fabricate poly styrene-co-acrylonitrile (SAN)-grafted-CNTs via atom transfer radical polymerization (ATRP). The in-situ ATRP grafting approach was successfully employed to graft polystyrene (PS), SAN and polyacrylonitrile (PAN), onto the convex surfaces of pristine MWCNTs (PCNT) and acid-functionalized MWCNTs (FCNT). Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H-NMR), and thermogravimetric analysis (TGA) confirmed the effectiveness of the modification via the ATRP grafting approach. The molar composition of acrylonitrile in the synthesized copolymer on the surface of CNTs for an FCNTs was calculated to be about 80% and 67.5% by 1H-NMR and TGA respectively, whereas the value is lower for PCNTs. Morphological studies showed that SAN-grafted FCNTs exhibit rougher surface morphology compared to the SAN-grafted PCNTs. Moreover, the higher diameter of the FCNTs indicated the higher polymer content, which was coated onto CNTs functionalized by vapor-phase oxidation. Therefore, the vapor phase oxidation strategy employed in this study could be utilized as a general method to prepare CNTs which can serve as an ATRP macroinitiator for the fabrication of various polymer grafted CNTs.

Cholesterol and its esters as serum biomarkers in malignant obstructive jaundice: a single step 1H NMR metabolomic approach

Metabolomics ◽  
2013 ◽  
Vol 9 (6) ◽  
pp. 1181-1191 ◽  
Author(s):  
Shatakshi Srivastava ◽  
Raja Roy ◽  
Santosh Kumar ◽  
Hari Om Gupta ◽  
Devendra Singh ◽  
...  
Keyword(s):  
Obstructive Jaundice ◽  
1H Nmr ◽  
Single Step ◽  
Serum Biomarkers ◽  
Malignant Obstructive Jaundice ◽  
Metabolomic Approach

Iridium-Catalyzed Triborylation of 3-Substituted Indoles

2015 ◽  
Vol 68 (12) ◽  
pp. 1810 ◽  
Author(s):  
Andrew S. Eastabrook ◽  
Jonathan Sperry
Keyword(s):  
1H Nmr ◽  
Nmr Analysis ◽  
One Pot ◽  
Substitution Pattern ◽  
The Third

Readily available 3-substituted indoles undergo a one-pot iridium-catalyzed triborylation at the C2, C5, and C7 sites. 1H NMR analysis indicates borylation at C2 and C7 occurs first (no monoborylated product is observed), with the third borylation occurring as a separate, distinct step that is sterically directed to C5 by a combination of the substituent at C3 and the boronate at C7. The resulting tetrasubstituted indoles possess a substitution pattern that is cumbersome to prepare using existing methods.

ChemInform Abstract: A 1H NMR Method for the Determination of Enantiomeric Excess and Absolute Configuration of cis-Dihydrodiol Metabolites of Polycyclic Arenes and Heteroarenes.

ChemInform ◽  
2010 ◽  
Vol 23 (40) ◽  
pp. no-no
Author(s):  
D. R. BOYD ◽  
N. D. SHARMA ◽  
R. BOYLE ◽  
R. A. S. MCMORDIE ◽  
J. CHIMA ◽  
...  
Keyword(s):  
1H Nmr ◽  
Absolute Configuration ◽  
Enantiomeric Excess ◽  
Nmr Method

scholarly journals Fingerprinting Acute Digestive Diseases by Untargeted NMR Based Metabolomics

2018 ◽  
Vol 19 (11) ◽  
pp. 3288 ◽  
Author(s):  
Panteleimon Takis ◽  
Antonio Taddei ◽  
Riccardo Pini ◽  
Stefano Grifoni ◽  
Francesca Tarantini ◽  
...  
Keyword(s):  
Abdominal Pain ◽  
1H Nmr ◽  
Intestinal Ischemia ◽  
Principal Component ◽  
Disease Diagnosis ◽  
Proton Nuclear Magnetic Resonance ◽  
Mechanical Obstruction ◽  
Symptomatic Gallstones ◽  
Symptom Group ◽  
Upper Abdominal

Precision medicine may significantly contribute to rapid disease diagnosis and targeted therapy, but relies on the availability of detailed, subject specific, clinical information. Proton nuclear magnetic resonance (1H–NMR) spectroscopy of body fluids can extract individual metabolic fingerprints. Herein, we studied 64 patients admitted to the Florence main hospital emergency room with severe abdominal pain. A blood sample was drawn from each patient at admission, and the corresponding sera underwent 1H–NMR metabolomics fingerprinting. Unsupervised Principal Component Analysis (PCA) analysis showed a significant discrimination between a group of patients with symptoms of upper abdominal pain and a second group consisting of patients with diffuse abdominal/intestinal pain. Prompted by this observation, supervised statistical analysis (Orthogonal Partial Least Squares–Discriminant Analysis (OPLS-DA)) showed a very good discrimination (>90%) between the two groups of symptoms. This is a surprising finding, given that neither of the two symptoms points directly to a specific disease among those studied here. Actually herein, upper abdominal pain may result from either symptomatic gallstones, cholecystitis, or pancreatitis, while diffuse abdominal/intestinal pain may result from either intestinal ischemia, strangulated obstruction, or mechanical obstruction. Although limited by the small number of samples from each of these six conditions, discrimination of these diseases was attempted. In the first symptom group, >70% discrimination accuracy was obtained among symptomatic gallstones, pancreatitis, and cholecystitis, while for the second symptom group >85% classification accuracy was obtained for intestinal ischemia, strangulated obstruction, and mechanical obstruction. No single metabolite stands up as a possible biomarker for any of these diseases, while the contribution of the whole 1H–NMR serum fingerprint seems to be a promising candidate, to be confirmed on larger cohorts, as a first-line discriminator for these diseases.

scholarly journals One-Dimensional 13C NMR Is a Simple and Highly Quantitative Method for Enantiodiscrimination

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1785 ◽  
Author(s):  
Peter Lankhorst ◽  
Jozef van Rijn ◽  
Alexander Duchateau
Keyword(s):  
1H Nmr ◽  
13C Nmr ◽  
Quantitative Method ◽  
Enantiomeric Excess ◽  
Nmr Spectrum ◽  
One Dimensional ◽  
Nmr Method ◽  
Relative Standard ◽  
Excess Value ◽  
Chiral Solvating Agent

The discrimination of enantiomers of mandelonitrile by means of 1D 13C NMR and with the aid of the chiral solvating agent (S)-(+)-1-(9-anthryl)-2,2,2-trifluoroethanol (TFAE) is presented. 1H NMR fails for this specific compound because proton signals either overlap with the signals of the chiral solvating agent or do not show separation between the (S)-enantiomer and the (R)-enantiomer. The 13C NMR method is validated by preparing artificial mixtures of the (R)-enantiomer and the racemate, and it is shown that with only 4 mg of mandelonitrile a detection limit of the minor enantiomer of 0.5% is obtained, corresponding to an enantiomeric excess value of 99%. Furthermore, the method shows high linearity, and has a small relative standard deviation of only 0.3% for the minor enantiomer when the relative abundance of this enantiomer is 20%. Therefore, the 13C NMR method is highly suitable for quantitative enantiodiscrimination. It is discussed that 13C NMR is preferred over 1H NMR in many situations, not only in molecules with more than one chiral center, resulting in complex mixtures of many stereoisomers, but also in the case of molecules with overlapping multiplets in the 1H NMR spectrum, and in the case of molecules with many quaternary carbon atoms, and therefore less abundant protons.

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