Mixed oxo-hydroxy bile acids as actual or potential impurities in ursodeoxycholic acid preparation: a 1H and 13C NMR study

Bettarello, Lisa; Bortolini, Olga; Fantin, Giancarlo; Guerrini, Alessandra

doi:10.1016/s0014-827x(99)00121-4

Cited by 10 publications

(4 citation statements)

References 18 publications

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“…16 Both the 1 H and 13 C NMR signals of the A/B ring system of 1 agreed much better with the corresponding signals of 7α-hydroxycholestan-3-one than with those of 7α-hydroxy-24-nor-5β-cholan-3-one. 17 In particular, the 1 H NMR spectrum of 7α-hydroxy-24-nor-5β-cholan-3-one has a signal assigned to an H-4 proton at 3.39 ppm (t, J = 15); 18 the H-4 protons in 1 resonate at 1.93 and 2.35 ppm and those in 7α-hydroxycholestan-3-one at 1.95 and 2.36 ppm (Table 1). The α-configuration of H-5 was supported by a NOESY correlation observed from H-6 axial (δ 1.57, td, J = 14.5, 2.5 Hz) and the C-19 methyl group (δ 1.04); such a correlation would not be possible if H-5 had the β-configuration.…”

Section: Resultsmentioning

confidence: 99%

“…Finally, the 13 C NMR chemical shift of the C-19 methyl in AB-trans-fused 3-keto-7α-hydroxy steroids appears around 10.4 ppm, while in the corresponding cis-fused series it appears between 12 and 22 ppm. 18 A calculation of the 13 C NMR shifts of both 1 and 5-epi-tauromantellic acid using commercially available software gave results in reasonably good agreement between the calculated and observed values for 1, while the calculated values for 5-epi-tauromantellic acid differed widely from the observed values for C-9 (calculated 33.2 ppm, observed 45.2 ppm) and C-19 (calculated 21.9 ppm, observed 10.4 ppm).…”

Section: ■ Results and Discussionmentioning

confidence: 99%

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An Endogenous Bile Acid and Dietary Sucrose from Skin Secretions of Alkaloid-Sequestering Poison Frogs

et al. 2012

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The skins of Madagascar poison frogs (Mantella) and certain Neotropical poison frogs (Epipedobates, Dendrobates) secrete the new bile acid tauromantellic acid (1), which was found in both wild-caught and captive-born frogs. This is the first molecule of endogenous origin detected in skin secretions from these taxa. Sucrose was also detected in secretions from wild-caught Mantella but not in captive-born frogs, suggesting a dietary origin.

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Section: Resultsmentioning

confidence: 99%

Section: ■ Results and Discussionmentioning

confidence: 99%

An Endogenous Bile Acid and Dietary Sucrose from Skin Secretions of Alkaloid-Sequestering Poison Frogs

et al. 2012

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“…In comparison with NaDC, the 13 C NMR spectrum of the oxidation product showed the appearance of a signal of carbonyl carbon at 216.18 ppm and the loss of a signal of carbon atom attached to an oxygen atom, suggesting that a hydroxyl group of NaDC was selectively oxidized to a carbonyl group. It can be inferred that the oxidized hydroxyl was at the C3 position, and the product was sodium 3-keto-12-hydroxy-cholanate (3-KHC) (see Scheme 1) by comparison of 13 C-NMR and 1 H-NMR data with those reported [35][36][37][38].…”

Section: Chemical Oxidation Of Nadc To 3-khc Catalyzed By Au Npsmentioning

confidence: 99%

Oxidation of Sodium Deoxycholate Catalyzed by Gold Nanoparticles and Chiral Recognition Performances of Bile Salt Micelles

Wang

Chen

et al. 2019

Molecules

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Au nanoparticles (NPs) were prepared by UV light irradiation of a mixed solution of HAuCl4 and sodium deoxycholate (NaDC) under alkaline condition, in which NaDC served as both reducing agent and capping agent. The reaction was monitored by circular dichroism (CD) spectra, and it was found that the formed gold NPs could catalyze the oxidation of NaDC. A CD signal at ~283 nm in the UV region was observed for the oxidation product of NaDC. The intensity of the CD signal of the oxidation product was enhanced gradually with the reaction time. Electrospray ionization (ESI) mass spectra and nuclear magnetic resonance (NMR) spectra were carried out to determine the chemical composition of the oxidation product, revealing that NaDC was selectively oxidized to sodium 3-keto-12-hydroxy-cholanate (3-KHC). The chiral discrimination abilities of the micelles of NaDC and its oxidation product, 3-KHC, were investigated by using chiral model molecules R,S-1,1′-Binaphthyl-2,2′-diyl hydrogenphosphate (R,S-BNDHP). Compared with NaDC, the micelles of 3-KHC displayed higher binding ability to the chiral model molecules. In addition, the difference in binding affinity of 3-KHC micelles towards R,S-isomer was observed, and S-isomer was shown to preferentially bind to the micelles.

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“…As the most reliable and simplest sample preparation analytical method, high field NMR spectroscopy has been exploited for BA identification and quantification. Proton NMR spectroscopy has been used to study the molecular conformation of seven different bile salts in micelles [58]. A separate study demonstrated that C18 methyl proton signal (around 0.7 ppm) obtained from 1 H-NMR spectroscopy can be used for quantitative analysis of total and taurine-conjugated BAs [59].…”

Section: Nuclear Magnetic Resonance (Nmr) Spectroscopy Based Assaysmentioning

confidence: 99%

A review of analytical platforms for accurate bile acid measurement

et al. 2019

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Bile acids are acidic steroids which help in lipid absorption, act as signaling molecules, and are key intermediate molecules between host and gut microbial metabolism. Perturbations in the circulating bile acid pool can lead to dysregulated metabolic and immunological function which often cause liver and intestinal diseases. Bile acids have chemically diverse structures and are present in broad range of biological concentrations in a wide variety of samples with complex biological matrices. Advanced analytical methods are therefore required to identify and accurately quantify individual bile acids. Though enzymatic determination of total bile acid is most popular in clinical laboratories, these methods provide limited information about individual bile acids. Advanced analytical methods such as gas chromatography-and liquid chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy have now emerged as highly informative techniques which help in identification and quantification of individual bile acids in complex biological matrices. Here, we review the detection technologies currently used for bile acid identification and quantification. We further discuss the advantages and disadvantages of these analytical techniques with respect to sensitivity, specificity, robustness, and ease of use.

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Mixed oxo-hydroxy bile acids as actual or potential impurities in ursodeoxycholic acid preparation: a 1H and 13C NMR study

Cited by 10 publications

References 18 publications

An Endogenous Bile Acid and Dietary Sucrose from Skin Secretions of Alkaloid-Sequestering Poison Frogs

An Endogenous Bile Acid and Dietary Sucrose from Skin Secretions of Alkaloid-Sequestering Poison Frogs

Oxidation of Sodium Deoxycholate Catalyzed by Gold Nanoparticles and Chiral Recognition Performances of Bile Salt Micelles

A review of analytical platforms for accurate bile acid measurement

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