scholarly journals Synthesis, Fluorescence and NMR Spectroscopic Studies of a Novel Phosphinoxido-18-crown-6 Ether Containing an Anthracene Fluorophore Unit

2019 ◽  
Vol 64 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Hajnalka Szabó-Szentjóbi ◽  
Anna Márton ◽  
Dávid Pál ◽  
Gergő Dargó ◽  
Áron Szigetvári ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
Spectroscopic Studies ◽  
Primary Amines ◽  
Methyl Groups ◽  
Amino Acid Esters ◽  
Two Dimensional ◽  
Fluorescent Chemosensors ◽  
One Dimensional ◽  
Stereogenic Centers ◽  
Acid Esters

The synthesis of the (R,R) and (S,S) enantiomers of a new enantiopure monophospha-18-crown-6 ether (1), which contains an anthracene fluorophore unit and methyl groups at its stereogenic centers, was accomplished. The structure of one enantiomer ((S,S)-1) was studied using one-dimensional (1H, 13C{1H}, and 31P{1H}) and two-dimensional NMR spectra. Because (R,R)-1 and (S,S)-1 can act as new fluorescent chemosensors, we examined their enantiomeric differentiation abilities toward the enantiomers of protonated chiral primary amines and amino acid esters (PEA, 1-NEA, PGME, PAME) using UV-Vis and fluorescence spectroscopies. These monophospha-crown ethers showed moderate enantiomeric discrimination abilities.

scholarly journals Fluorescence Assay for the Determination of d-Panthenol Based on Novel Ring-Fused 2-Pyridone Derivative

2020 ◽  
Vol 21 (21) ◽  
pp. 8386
Author(s):  
Wiktor Kasprzyk ◽  
Tomasz Świergosz ◽  
Filip Koper
Keyword(s):  
Citric Acid ◽  
Nmr Spectra ◽  
Chemical Structure ◽  
Accurate Determination ◽  
Pharmaceutical Formulations ◽  
Two Dimensional ◽  
One Dimensional ◽  
Fluorescent Method ◽  
Derivatizing Agent

Herein, a novel fluorescent method for the determination of d-panthenol (DP) level in solutions with no separate hydrolysis step has been revealed based on the utilization of citric acid (CA) as a derivatizing agent. Consequently, the essential parameters of the derivatization process were established, resulting in the development of sensitive, repeatable, and accurate determination of panthenol. The method was approved, and its usefulness in characterizing the concentration of DP in pharmaceutical formulations and selectivity in the determination of DP were validated. The chemical structure of the new fluorophore formulating in the reaction in DP with CA, i.e., 6-oxo-3,4-dihydro-2H,6H-pyrido[2,1-b][1,3]oxazine-8-carboxylic acid (ODPC), was elucidated using detailed NMR experiments: one-dimensional (1H, 13C) as well as two-dimensional NMR spectra (1H-1H COSY, 1H-13C HSQC, 1H-13C HMBC, 1H-15N HSQC, 1H-15N HMBC).

scholarly journals New 3-Hydroxyquinaldic Acid Derivatives from Cultures of the Marine Derived Actinomycete Streptomyces cyaneofuscatus M-157

Marine Drugs ◽  
2018 ◽  
Vol 16 (10) ◽  
pp. 371 ◽  
Author(s):  
Francisco Ortiz-López ◽  
Elsa Alcalde ◽  
Aida Sarmiento-Vizcaíno ◽  
Caridad Díaz ◽  
Bastien Cautain ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
2D Nmr ◽  
Two Dimensional ◽  
Amino Acid Residues ◽  
Trace Level ◽  
One Dimensional ◽  
2D Nmr Spectra ◽  
Ic50 Values ◽  
New Compounds ◽  
Tof Ms

Fractionation of the bioactive extract of a culture of the marine derived actinomycete Streptomyces cyaneofuscatus M-157 led to the isolation of the known 3-hydroxyquinaldic acid (4), its amide (5) and three new derivatives (1–3) containing different amino acid residues. The structures of the new molecules (1–3), including their absolute configuration, were determined by the analysis of their ESI-TOF MS and one-dimensional (1D) and two-dimensional (2D) NMR spectra and advanced Marfey’s analysis of their hydrolyzation products. Compound 3 spontaneously dimerized in solution to give the disulfide derivative 6. Unfortunately, none of the new compounds isolated confirmed the antimicrobial activity found in the bacterial extract, perhaps indicating that such antibacterial activity might be due to presence in the extract at the trace level of larger bioactive 3-hydroxyquinaldic acid derivatives from which compounds 1–3 are biosynthetic precursors. Cytotoxicity tests confirmed the moderate and weak IC50 values of 15.6 and 51.5 µM for compounds 5 and 1, respectively.

scholarly journals Fast profiling of metabolite mixtures using chemometric analysis of a speeded-up 2D heteronuclear correlation NMR experiment

RSC Advances ◽  
2017 ◽  
Vol 7 (47) ◽  
pp. 29860-29870 ◽  
Author(s):  
Rakesh Sharma ◽  
Navdeep Gogna ◽  
Harpreet Singh ◽  
Kavita Dorai
Keyword(s):  
Nmr Spectra ◽  
2D Nmr ◽  
Chemometric Analysis ◽  
Two Dimensional ◽  
Metabolite Fingerprinting ◽  
Heteronuclear Correlation ◽  
One Dimensional

One-dimensional (1D) NMR spectra of mixtures of metabolites suffer from severe overlap of spectral resonances and hence recent research in NMR-based metabolomics focuses on using two-dimensional (2D) NMR experiments for metabolite fingerprinting.

scholarly journals Synthesis of novel pregnane-based 20-carboxamides via palladium-catalysed aminocarbonylation

2021 ◽  
Author(s):  
Gábor Mikle ◽  
Alexandra Zugó ◽  
Erzsébet Szatnik ◽  
Anita Maxim ◽  
Sándor Mahó ◽  
...  
Keyword(s):  
Amino Acid ◽  
Selective Hydrogenation ◽  
Primary Amines ◽  
Amino Acid Esters ◽  
Acid Esters

Abstract20-Carboxamidopregnene derivatives, such as 3β-acetoxy-5α-pregn-20-ene-20-carboxamides and 5α-pregn-20-ene-20-carboxamides were synthesized from the widely accessible 3β-acetoxy-pregn-5,16-dien-20-one (PDA) using selective hydrogenation, hydrazine and iodoalkene formation, as well as palladium-catalysed aminocarbonylation. The 20-iodo-20-ene derivatives, obtained from the corresponding 20-keto derivatives via their hydrazones, served as substrates. 23 new 20-carboxamides were obtained using various N-nucleophiles ranging from simple primary amines to α-amino acid esters. The novelty of this methodology lies in the application of facile, moderate or high-yielding reactions to obtain otherwise hardly accessible steroidal 20-carboxamides of pharmaceutical importance. In other words, instead of the enzymatic or synthetic degradation of e.g., sterols or cholanic acids, functionalization of the basic skeleton (a ‘building-up’ approach) was used.

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