α-Lipoic acid in dietary supplements: Development and comparison of HPLC-CEAD and HPLC-ESI-MS methods

Durrani, Arjumand Iqbal; Schwartz, Heidi; Schmid, Walther; Sontag, Gerhard

doi:10.1016/j.jpba.2007.08.003

Cited by 43 publications

(39 citation statements)

References 20 publications

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“…Liquid chromatography-ESI-MS measurements, in negative mode, were carried out for the quantification of ALA in plasma, and the observed peak at m/z 205.0 was attributed to [ALA-H] À [26]. In the present work, ESI-MS measurements, in negative mode, of ALA showed: i) the principal peak at m/z of 205.04; ii) a peak at m/z of 411.09, which could be attributed to the dimmer of ALA; iii) a third signal at m/z of 171.06, which seems to correspond to the fragment ion [ALA-H 2 S-H] À , as it was reported elsewhere [27]. The three peaks were observed in all series of spectra obtained for ALA and for Hg 2þ :ALA at different proportions.…”

Section: Resultssupporting

confidence: 80%

Complexation of Hg²⁺ with α‐Lipoic and Dihydrolipoic Acids: Study by Differential Pulse Voltammetry on Rotating Au‐Disk Electrode and ESI‐MS

Chekmeneva

Dı́az-Cruz²,

Ariño

et al. 2010

Electroanalysis

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The complexation of the natural antioxidants a-lipoic acid (ALA) and its reduced form dihydrolipoic acid (DHLA) with Hg 2þ was investigated by a recently proposed differential pulse voltammetric (DPV) method using the rotating Au-disk electrode. Complexation processes are proposed from the multivariate curve resolution by alternating least squares (MCR-ALS) analysis of DPV titration data. Main complexes were both 1 : 1 Hg : ALA and Hg : DHLA, although the formation of 1 : 2 complexes can be also deduced. ALA and DHLA show different Hg 2þ -binding patterns at different pH. Voltammetric findings are completed with the data obtained by electrospray ionization massspectrometry (ESI-MS), especially in negative mode.

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Section: Resultssupporting

confidence: 80%

Complexation of Hg²⁺ with α‐Lipoic and Dihydrolipoic Acids: Study by Differential Pulse Voltammetry on Rotating Au‐Disk Electrode and ESI‐MS

Chekmeneva

Dı́az-Cruz²,

Ariño

et al. 2010

Electroanalysis

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“…However, it was found the tissue LA is essentially protein bound, and thus complicated sample preparation steps including protease digestion and solvent extraction are required until liberated free LA is detected by high sensitive methods even at the picomole range such as HPLC with various detection systems such as ultraviolet (UV), fluorescence (FL) and electrochemical (EC) detectors [22][23] . For example, Durrani et al 24) developed a method for the determination of LA in dietary supplements based on high performance liquid chromatography coupled with a coulometric electrode array detector (CEAD) and an electrospray ionization mass spectrometer (ESI-MS). In this method, LA was first extracted with methanol by sonication, following chromatographic separation by isocratic elution using an ACE 3-C-18 column, and then LA was detected by means of a CEAD against palladium reference electrodes.…”

Section: Determination Of Protein Bound Lamentioning

confidence: 99%

Activity assay of Lipoamidase, an expected modulator of metabolic fate of externally administered lipoic acid

Wang

Motafakkerazad

Matsugo

et al. 2011

Inflammation and Regeneration

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α-Lipoic acid (LA) is a cofactor functioning in four multienzymes: pyruvate dehydrogenase, α-ketoglutarate dehydrogenase, branched-chain α-keto acid dehydrogenase, and the glycine cleavage enzyme systems. In each enzyme, LA is covalently bound to the ε-amino group of lysine residues. LA has been used as a medicine for treating diabetic condition in Europe and is also currently a popular supplement resource, and thus the metabolic fate after orally intake of LA attracts much attention whether externally administered LA is incorporated into protein bound form because large fraction of administered dose is not fully explained yet. Lipoamidase is the enzyme catalyzing formation and breakage of amide bond between LA and lysine ε-amino groups in the protein and thus is expected to play critical role in LA metabolism and function. In order to know how the enzyme lipoamidase is involved in the fate of LA in the body, a simple assay method is requested for determining lipoamidase activity in tissues. The method using simple HPLC detection of newly synthesized fluorescent substrate, dansyl-α-lipoyllysine, is discussed together with other previously reported methods. Rec.2/26

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“…The extracts were analyzed using a previous proposed LC/MS/MS method and all MS experiments were performed using electrospray ionization (ESI) mode; we were only able to measure the relative amount of parent drug IBU (data not shown) [27,28].…”

Section: S1mentioning

confidence: 99%

Ibuprofen and Glutathione Conjugate as a Potential Therapeutic Agent for Treating Alzheimer's Disease

Pinnen

Sozio

Cacciatore

et al. 2010

Archiv der Pharmazie

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Non-steroidal anti-inflammatory drugs (NSAIDs) and antioxidant therapy might protect against the development of Alzheimer's disease (AD). In the present work, we synthesized a molecular combination of glutathione (GSH) and ibuprofen (IBU) via an amide bond and investigated its potential for targeted delivery of the parent drugs to neurons, where cellular oxidative stress and inflammation are related to AD. Evaluation of its physicochemical and in-vitro antioxidant properties indicated that compound 1 exhibits good stability toward human plasma enzymatic activity, and, like GSH, displays in-vitro free radical scavenging activity in a time and concentration-dependent manner. The new compound was also assessed by infusion in a rat model for Alzheimer's disease for its potential to antagonize the deleterious structural and cognitive effects of β-amyloid(1-40). In behavioral tests of long-term spatial memory, animals treated with codrug 1 performed significantly better than those treated with β-amyloid (Aβ) peptide. Histochemical findings confirmed the behavioral data, revealing that Aβ protein was less expressed in cerebral cortex treated with 1 than that treated with IBU. Taken together, the present findings suggest that conjugate 1 treatment may protect against the oxidative stress generated by reactive oxygen species (ROS) and the cognitive dysfunction induced by intracerebroventricular (i.c.v.) infusion of Aβ(1-40) in rats, and thus that codrug 1 could prove useful as a tool for controlling AD induced cerebral amyloid deposits and behavioral deterioration.

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α-Lipoic acid in dietary supplements: Development and comparison of HPLC-CEAD and HPLC-ESI-MS methods

Cited by 43 publications

References 20 publications

Complexation of Hg²⁺ with α‐Lipoic and Dihydrolipoic Acids: Study by Differential Pulse Voltammetry on Rotating Au‐Disk Electrode and ESI‐MS

Complexation of Hg²⁺ with α‐Lipoic and Dihydrolipoic Acids: Study by Differential Pulse Voltammetry on Rotating Au‐Disk Electrode and ESI‐MS

Activity assay of Lipoamidase, an expected modulator of metabolic fate of externally administered lipoic acid

Ibuprofen and Glutathione Conjugate as a Potential Therapeutic Agent for Treating Alzheimer's Disease

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α-Lipoic acid in dietary supplements: Development and comparison of HPLC-CEAD and HPLC-ESI-MS methods

Cited by 43 publications

References 20 publications

Complexation of Hg2+ with α‐Lipoic and Dihydrolipoic Acids: Study by Differential Pulse Voltammetry on Rotating Au‐Disk Electrode and ESI‐MS

Complexation of Hg2+ with α‐Lipoic and Dihydrolipoic Acids: Study by Differential Pulse Voltammetry on Rotating Au‐Disk Electrode and ESI‐MS

Activity assay of Lipoamidase, an expected modulator of metabolic fate of externally administered lipoic acid

Ibuprofen and Glutathione Conjugate as a Potential Therapeutic Agent for Treating Alzheimer's Disease

Contact Info

Product

Resources

About

Complexation of Hg²⁺ with α‐Lipoic and Dihydrolipoic Acids: Study by Differential Pulse Voltammetry on Rotating Au‐Disk Electrode and ESI‐MS

Complexation of Hg²⁺ with α‐Lipoic and Dihydrolipoic Acids: Study by Differential Pulse Voltammetry on Rotating Au‐Disk Electrode and ESI‐MS