scholarly journals Aerobic Metabolism of 4-Hydroxybenzoic Acid in Archaea via an Unusual Pathway Involving an Intramolecular Migration (NIH Shift)

2002 ◽  
Vol 68 (12) ◽  
pp. 6246-6255 ◽  
Author(s):  
D. J. Fairley ◽  
D. R. Boyd ◽  
N. D. Sharma ◽  
C. C. R. Allen ◽  
P. Morgan ◽  
...  
Keyword(s):  
Protocatechuic Acid ◽  
Cell Suspensions ◽  
Proton Nuclear Magnetic Resonance ◽  
Gas Chromatography Mass Spectrometry ◽  
Structural Isomer ◽  
Resonance Spectroscopy ◽  
Carboxyl Group ◽  
Hydroxybenzoic Acid ◽  
Group Migration ◽  
Do So

ABSTRACT A novel haloarchaeal strain, Haloarcula sp. strain D1, grew aerobically on 4-hydroxybenzoic acid (4HBA) as a sole carbon and energy source and is the first member of the domain Archaea reported to do so. Unusually, D1 metabolized 4HBA via gentisic acid rather than via protocatechuic acid, hydroquinone, or catechol. Gentisate was detected in 4HBA-grown cultures, and gentisate 1,2-dioxygenase activity was induced in 4HBA-grown cells. Stoichiometric accumulation of gentisate from 4HBA was demonstrated in 4HBA-grown cell suspensions containing 2,2′-dipyridyl (which strongly inhibits gentisate 1,2-dioxygenase). To establish whether initial 1-hydroxylation of 4HBA with concomitant 1,2-carboxyl group migration to yield gentisate occurred, 2,6-dideutero-4HBA was synthesized and used as a substrate. Deuterated gentisate was recovered from cell suspensions and identified as 3-deutero-gentisate, using gas chromatography-mass spectrometry and proton nuclear magnetic resonance spectroscopy. This structural isomer would be expected only if a 1,2-carboxyl group migration had taken place, and it provides compelling evidence that the 4HBA pathway in Haloarcula sp. strain D1 involves a hydroxylation-induced intramolecular migration. To our knowledge, this is the first report of a pathway which involves such a transformation (called an NIH shift) in the domain Archaea.

Zur Biosynthese der Benzoesäure in Gaultheria procumbens L. II

1964 ◽  
Vol 19 (9) ◽  
pp. 781-783 ◽  
Author(s):  
Hans Grisebach ◽  
Karl-Otto Vollmer
Keyword(s):  
Salicylic Acid ◽  
Cinnamic Acid ◽  
Protocatechuic Acid ◽  
Total Activity ◽  
Syringic Acid ◽  
The Other ◽  
Carboxyl Group ◽  
Hydroxybenzoic Acid ◽  
Benzoic Acids ◽  
Gaultheria Procumbens

Further investigations on the biosynthesis of benzoic acids in Gaultheria procumbens L. have shown that besides salicylic acid all the other benzoic acids (gentisinic acid, p-hydroxybenzoic acid, protocatechuic acid, o-pyrocatechuic acid(?), syringic acid and vanillinic acid) can be formed from cinnamic acid. In the case of vanillinic acid it was proved that the total activity is located in the carboxyl group when cinnamic acid-[3-14C] is the precursor.Formiat-14C is incorporated into the methylester group of methylsalicylate.

scholarly journals An Optimization of Liquid–Liquid Extraction of Urinary Volatile and Semi-Volatile Compounds and Its Application for Gas Chromatography-Mass Spectrometry and Proton Nuclear Magnetic Resonance Spectroscopy

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3651
Author(s):  
Natalia Drabińska ◽  
Piotr Młynarz ◽  
Ben de Lacy Costello ◽  
Peter Jones ◽  
Karolina Mielko ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Gas Chromatography ◽  
1H Nmr ◽  
Biomarker Discovery ◽  
Liquid Extraction ◽  
Proton Nuclear Magnetic Resonance ◽  
Gas Chromatography Mass Spectrometry ◽  
Resonance Spectroscopy ◽  
Liquid Liquid Extraction

Urinary volatile compounds (VCs) have been recently assessed for disease diagnoses. They belong to very diverse chemical classes, and they are characterized by different volatilities, polarities and concentrations, complicating their analysis via a single analytical procedure. There remains a need for better, lower-cost methods for VC biomarker discovery. Thus, there is a strong need for alternative methods, enabling the detection of a broader range of VCs. Therefore, the main aim of this study was to optimize a simple and reliable liquid–liquid extraction (LLE) procedure for the analysis of VCs in urine using gas chromatography-mass spectrometry (GC-MS), in order to obtain the maximum number of responses. Extraction parameters such as pH, type of solvent and ionic strength were optimized. Moreover, the same extracts were analyzed using Proton Nuclear Magnetic Resonance Spectroscopy (1H-NMR), to evaluate the applicability of a single urine extraction for multiplatform purposes. After the evaluation of experimental conditions, an LLE protocol using 2 mL of urine in the presence of 2 mL of 1 M sulfuric acid and sodium sulphate extracted with dichloromethane was found to be optimal. The optimized method was validated with the external standards and was found to be precise and linear, and allowed for detection of >400 peaks in a single run present in at least 50% of six samples—considerably more than the number of peaks detected by solid-phase microextracton fiber pre-concentration-GC-MS (328 ± 6 vs. 234 ± 4). 1H-NMR spectroscopy of the polar and non-polar extracts extended the range to >40 more (mainly low volatility compounds) metabolites (non-destructively), the majority of which were different from GC-MS. The more peaks detectable, the greater the opportunity of assessing a fingerprint of several compounds to aid biomarker discovery. In summary, we have successfully demonstrated the potential of LLE as a cheap and simple alternative for the analysis of VCs in urine, and for the first time the applicability of a single urine solvent extraction procedure for detecting a wide range of analytes using both GC-MS and 1H-NMR analysis to enhance putative biomarker detection. The proposed method will simplify the transport between laboratories and storage of samples, as compared to intact urine samples.

scholarly journals The binding behaviours between cyclopentanocucurbit[6]uril and three amino acids

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Siyuan Cheng ◽  
Weiwei Zhao ◽  
Xinan Yang ◽  
Ye Meng ◽  
Liantong Wei ◽  
...  
Keyword(s):  
Amino Acids ◽  
Self Assembly ◽  
Proton Nuclear Magnetic Resonance ◽  
Titration Calorimetry ◽  
Resonance Spectroscopy ◽  
Carboxyl Group ◽  
X Ray ◽  
Alkyl Chains ◽  
X Ray Crystallography ◽  
External Conditions

Binding behaviours between cyclopentanocucurbit[6]uril (CyP 6 Q[6]) and three amino acids have been investigated by means of X-ray crystallography, proton nuclear magnetic resonance spectroscopy and isothermal titration calorimetry. The results showed that CyP 6 Q[6] forms a 1 : 2 inclusion complex with glycine, but 1 : 1 complexes with both leucine and lysine. Whereas the carboxyl group of glycine can enter the interior of the cavity of CyP 6 Q[6], only the alkyl chains of leucine and lysine can enter this cavity. Interestingly, leucine can adopt two different self-assembly modes upon its interaction with cucurbituril, depending on the external conditions, whereas glycine and lysine do not exhibit such behaviour.

scholarly journals Multiplatform Urinary Metabolomics Profiling to Discriminate Cachectic from Non-Cachectic Colorectal Cancer Patients: Pilot Results from the ColoCare Study

Metabolites ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 178
Author(s):  
Jennifer Ose ◽  
Biljana Gigic ◽  
Tengda Lin ◽  
David B. Liesenfeld ◽  
Jürgen Böhm ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cancer Patients ◽  
Muscle Mass ◽  
Multiple Testing ◽  
Enrichment Analysis ◽  
Proton Nuclear Magnetic Resonance ◽  
Gas Chromatography Mass Spectrometry ◽  
Resonance Spectroscopy ◽  
Glycerol Phosphate ◽  
Colorectal Cancer Patients

Cachexia is a multifactorial syndrome that is characterized by loss of skeletal muscle mass in cancer patients. The biological pathways involved remain poorly characterized. Here, we compare urinary metabolic profiles in newly diagnosed colorectal cancer patients (stage I–IV) from the ColoCare Study in Heidelberg, Germany. Patients were classified as cachectic (n = 16), pre-cachectic (n = 13), or non-cachectic (n = 23) based on standard criteria on weight loss over time at two time points. Urine samples were collected pre-surgery, and 6 and 12 months thereafter. Fat and muscle mass area were assessed utilizing computed tomography scans at the time of surgery. N = 152 compounds were detected using untargeted metabolomics with gas chromatography–mass spectrometry and n = 154 features with proton nuclear magnetic resonance spectroscopy. Thirty-four metabolites were overlapping across platforms. We calculated differences across groups and performed discriminant and overrepresentation enrichment analysis. We observed a trend for 32 compounds that were nominally significantly different across groups, although not statistically significant after adjustment for multiple testing. Nineteen compounds could be identified, including acetone, hydroquinone, and glycine. Comparing cachectic to non-cachectic patients, higher levels of metabolites such as acetone (Fold change (FC) = 3.17; p = 0.02) and arginine (FC = 0.33; p = 0.04) were observed. The two top pathways identified were glycerol phosphate shuttle metabolism and glycine and serine metabolism pathways. Larger subsequent studies are needed to replicate and validate these results.

scholarly journals Fucoidans of Moroccan Brown Seaweed as Elicitors of Natural Defenses in Date Palm Roots

Marine Drugs ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. 596
Author(s):  
Soukaina Bouissil ◽  
Zainab El Alaoui-Talibi ◽  
Guillaume Pierre ◽  
Halima Rchid ◽  
Philippe Michaud ◽  
...  
Keyword(s):  
Date Palm ◽  
Lignin Content ◽  
Brown Seaweed ◽  
Complete Characterization ◽  
Size Exclusion ◽  
Proton Nuclear Magnetic Resonance ◽  
Gas Chromatography Mass Spectrometry ◽  
Sulfated Polysaccharides ◽  
Resonance Spectroscopy ◽  
Control Approach

Fucoidans from Moroccan brown seaweed Bifurcaria bifurcata and Fucus spiralis were tested for their elicitor activity after their purification and complete characterization. The fucoidans of B. bifurcata (BBF) and of F. spiralis (FSF) were extracted and purified then characterized by infrared spectroscopy, proton nuclear magnetic resonance spectroscopy and size exclusion chromatography. The results show that BBF and FSF are mainly sulfated with 45.49 and 49.53% (w/w) sulfate, respectively. Analysis of neutral sugars determined by gas chromatography–mass spectrometry showed that FSF and BBF were mainly composed of 64% and 91% fucose and 20% and 6% galactose, respectively, with a few other sugars such as glucose (8% in FSF), rhamnose (1% in BBF) and mannose (8% in FSF and, 2% in BBF). The eliciting activity of these sulfated polysaccharides in stimulating the natural defenses of the date palm was evaluated through the activity of phenylalanine ammonia-lyase (PAL), and the increase in phenols and lignin content in the roots. The results obtained clearly show that the two fucoidans early and intensely stimulate the natural defenses of the date palm after 24 h of treatments. This remarkable elicitor effect seems to be linked to the sulfated groups compared to non-sulfate alginates extracted from the same algae. These results open promising perspectives for a biological control approach against date palm diseases.

Thermal Stability Studies on 1, 3, 5, 7 - Tetramethylcyclotetra-Siloxane(TMCTS), a Low к CVD Precursor

2002 ◽  
Vol 716 ◽  
Author(s):  
C. Xu ◽  
A. S. Borovik ◽  
Z. Wang ◽  
J. Arno ◽  
T. H. Baum
Keyword(s):  
Thermal Stability ◽  
Elevated Temperatures ◽  
Degradation Kinetics ◽  
Water Concentration ◽  
Proton Nuclear Magnetic Resonance ◽  
Thermal Degradation Kinetics ◽  
Gas Chromatography Mass Spectrometry ◽  
Resonance Spectroscopy ◽  
Residual Water ◽  
Degradation Rates

AbstractChemical studies on 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS) were conducted to elucidate its thermal behaviors with water and under various reaction conditions. TMCTS was heated in the presence of 316L stainless steel and in the presence of water. The heated TMCTS then was evaluated using 1H NMR (proton nuclear magnetic resonance) spectroscopy, GC-MS (gas chromatography-mass spectrometry) as a function of time, temperature and residual water concentration. The thermal degradation kinetics of gas-phase TMCTS were investigated using FTIR (Fourier transform infrared) spectroscopy at elevated temperatures. These initial results indicated that TMCTS degradation rates increased with both temperature and water concentration. This work spawned the development of a “dry” TMCTS that is expected to exhibit enhanced thermal stability relative towards uncontrolled decomposition.

scholarly journals A Serum Metabolomics Classifier Derived from Elderly Patients with Metastatic Colorectal Cancer Predicts Relapse in the Adjuvant Setting

Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2762
Author(s):  
Samantha Di Donato ◽  
Alessia Vignoli ◽  
Chiara Biagioni ◽  
Luca Malorni ◽  
Elena Mori ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Risk Stratification ◽  
Elderly Patients ◽  
Metastatic Colorectal Cancer ◽  
Early Stage ◽  
Prospective Trial ◽  
Proton Nuclear Magnetic Resonance ◽  
P Value ◽  
Resonance Spectroscopy ◽  
Metabolomic Fingerprinting

Adjuvant treatment for patients with early stage colorectal cancer (eCRC) is currently based on suboptimal risk stratification, especially for elderly patients. Metabolomics may improve the identification of patients with residual micrometastases after surgery. In this retrospective study, we hypothesized that metabolomic fingerprinting could improve risk stratification in patients with eCRC. Serum samples obtained after surgery from 94 elderly patients with eCRC (65 relapse free and 29 relapsed, after 5-years median follow up), and from 75 elderly patients with metastatic colorectal cancer (mCRC) obtained before a new line of chemotherapy, were retrospectively analyzed via proton nuclear magnetic resonance spectroscopy. The prognostic role of metabolomics in patients with eCRC was assessed using Kaplan–Meier curves. PCA-CA-kNN could discriminate the metabolomic fingerprint of patients with relapse-free eCRC and mCRC (70.0% accuracy using NOESY spectra). This model was used to classify the samples of patients with relapsed eCRC: 69% of eCRC patients with relapse were predicted as metastatic. The metabolomic classification was strongly associated with prognosis (p-value 0.0005, HR 3.64), independently of tumor stage. In conclusion, metabolomics could be an innovative tool to refine risk stratification in elderly patients with eCRC. Based on these results, a prospective trial aimed at improving risk stratification by metabolomic fingerprinting (LIBIMET) is ongoing.

scholarly journals Occurrence of Cis-11,12-Methylene-Hexadecanoic Acid in the Red Alga Solieria pacifica (Yamada) Yoshida

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2286
Author(s):  
Gwang-Woo Kim ◽  
Jae-Man Sim ◽  
Yutaka Itabashi ◽  
Min-Jeong Jung ◽  
Joon-Young Jun
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Red Alga ◽  
Proton Nuclear Magnetic Resonance ◽  
Animal Origin ◽  
Monoenoic Acid ◽  
Resonance Spectroscopy ◽  
Hexadecenoic Acid ◽  
Cyclopropane Fatty Acid ◽  
Hexadecanoic Acid

Fatty acids in marine algae have attracted the attention of natural chemists because of their biological activity. The fatty acid compositions of the Solieriaceae families (Rhodophyceae, Gaigartinales) provide interesting information that unusual cyclic fatty acids have been occasionally found. A survey was conducted to profile the characteristic fatty acid composition of the red alga Solieria pacifica (Yamada) Yoshida using gas chromatography-mass spectrometry (GC-MS), infrared spectroscopy (IR), and proton nuclear magnetic resonance spectroscopy (1H-NMR). In S. pacifica, two cyclopentyl fatty acids, 11-cyclopentylundecanoic acid (7.0%), and 13-cyclopentyltridecanoic acid (4.9%), and a cyclopropane fatty acid, cis-11,12-methylene-hexadecanoic acid (7.9%) contributed significantly to the overall fatty acid profile. In particular, this cyclopropane fatty acid has been primarily found in bacteria, rumen microorganisms or foods of animal origin, and has not previously been found in any other algae. In addition, this alga contains a significant amount of the monoenoic acid cis-11-hexadecenoic acid (9.0%). Therefore, cis-11,12-methylene-hexadecanoic acid in S. pacifica was likely produced by methylene addition to cis-11-hexadecenoic acid.

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.

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