Determination of free α-lipoic acid in foodstuffs by HPLC coupled with CEAD and ESI-MS

Durrani, Arjumand Iqbal; Schwartz, Heidi; Nagl, Michael; Sontag, Gerhard

doi:10.1016/j.foodchem.2009.11.045

Cited by 53 publications

(19 citation statements)

References 22 publications

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“…In a large number of research studies exploring the efficacy of LA supplementation in different settings (mainly in relation to diabetic neuropathic treatment), LA resulted definitely safe even at high dosages (as high as 1200‐1800 mg/day for 5 years) . This is not surprising, considering that this molecule is contained in a wide range of aliments and thus it is continuously taken with the diet, even during pregnancy …”

Section: Pre‐clinical and Clinical Effects Of Inositol Plus α‐Lipoic mentioning

confidence: 97%

Inositol and antioxidant supplementation: Safety and efficacy in pregnancy

Formoso

Baldassarre

Ginestra

et al. 2019

Diabetes Metabolism Res

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Summary Pregnancies complicated by diabetes have largely increased in number over the last 50 years. Pregnancy is characterized by a physiologic increase in insulin resistance, which, associated with increased oxidative stress and inflammations, could induce alterations of glucose metabolism and diabetes. If not optimally controlled, these conditions have a negative impact on maternal and foetal outcomes. To date, one can resort only to diet and lifestyle to treat obesity and insulin resistance during pregnancy, and insulin remains the only therapeutic option to manage diabetes during pregnancy. However, in the last years, in a variety of experimental models, inositol and antioxidants supplementation have shown insulin‐sensitizing, anti‐inflammatory, and antioxidant properties, which could be mediated by some possible complementary mechanism of action. Different isomers and multiple combinations of these compounds are presently available: Aim of the present review article is to examine the existing evidence in order to clarify and/or define the effects of different inositol‐ and antioxidant‐based supplements during pregnancy complicated by insulin resistance and/or by diabetes. This could help the clinician's evaluation and choice of the appropriate supplementation regimen.

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Section: Pre‐clinical and Clinical Effects Of Inositol Plus α‐Lipoic mentioning

confidence: 97%

Inositol and antioxidant supplementation: Safety and efficacy in pregnancy

Formoso

Baldassarre

Ginestra

et al. 2019

Diabetes Metabolism Res

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“…The total lipoic acid (tLA; sum of the a-LA and DHLA) content of the biological samples consists of the free LA, weakly protein-bound LA via hydrogen bonds, and strongly protein-bound LA (lipoyllysine) via covalent bonds. However, various physiological functions of the LA (both a-LA and DHLA) are attributed to their free forms (free and weakly protein bound) [9].…”

mentioning

confidence: 99%

“…Several papers have been published on the chromatographic analysis of total, free, or bound a-LA in various sample matrices such as foodstuffs [9], dietary supplements [10], and biological samples [11][12][13][14][15][16]. Similarly, very few methods [17][18][19][20][21][22][23] are available for simultaneous determination of the total a-LA and its reduced form, DHLA, in biological samples after oral administration.…”

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confidence: 99%

Simultaneous Determination of the Endogenous Free α-Lipoic Acid and Dihydrolipoic Acid in Human Plasma and Erythrocytes by RP-HPLC with Electrochemical Detection

et al. 2011

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A highly sensitive, precise, and accurate reversed-phase high-performance liquid-chromatography/ electrochemical detection method for simultaneous determination of the endogenous free a-lipoic acid and dihydrolipoic acid in biological matrices was developed and validated. The two analytes were extracted from the samples with acetonitrile/10% metaphosphoric acid solution (aqueous) (50/50 v/v). To determine the total lipoic acid, samples were treated with tris(2-carboxyethyl)phosphine solution in phosphate buffer, pH 2.5 with 85% orthophosphoric acid prior to deproteination. The two analytes were separated on a C 18 (150 9 4.6 mm, 5 lm) analytical column using acetonitrile-50 mM phosphate buffer, pH 2.5 with 85% orthophosphoric acid (35/65 v/v) as the isocratic mobile phase pumped at a flow rate of 2.0 mL min -1 at the column oven temperature of 35°C. The column eluents were monitored at a potential of 0.9 V. These analytes were efficiently resolved in \7 min. The present method was sufficiently robust and specific for simultaneous determination of the two analytes and demonstrated acceptable values for linearity (r 2 = 0.999 in the range of 0.1-500 and 0.25-1,000 ng mL -1 for a-lipoic acid and dihydrolipoic acid, respectively), recovery ([97%), precision (RSD% \2), and sensitivity (on column limit of detection, 150 and 375 fg for a-lipoic acid and dihydrolipoic acid, respectively and limit of quantification: 0.5 and 1.25 pg for a-lipoic acid and dihydrolipoic acid, respectively), indicating that the proposed method was more sensitive, precise, economical, and versatile, and has higher throughput than the previously reported methods for simultaneous determination of the two analytes.

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“…LA and its reduced form, dihydrolipoic acid (DHLA) (Figure 2), play an important role in pathological conditions characterized by oxidative stress, 24,25 such as: (i) scavenger of ROS, (ii) capacity to increase the level of reduced glutathione and other antioxidant enzymes, (iii) downregulation of the inflammatory processes, (iv) scavenging of lipid peroxidation products, (v) redox active transition metal chelation, (vi) increase of ACh production by activation of choline acetyltransferase. 25 On the basis of such activities, LA can exert beneficial effects in AD, possibly stabilizing cognitive functions.…”

Section: Introductionmentioning

confidence: 99%

Two Novel Donepezil-Lipoic Acid Hybrids: Synthesis, Anticholinesterase and Antioxidant Activities and Theoretical Studies

Terra¹,

Silva²,

Tramarin³

et al. 2017

J. Braz. Chem. Soc.

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Alzheimer disease (AD) is a complex disease related to multiple pathogenic mechanisms. A strategy to develop effective drugs is based on the so-called multi-target directed ligands (MTDL) by using hybrid compounds. So, in the present study, we have designed and synthesized two hybrids, containing the indanone-piperidine moiety of donepezil, a drug approved for the treatment of AD, and the lipoic acid scaffold, an antioxidant compound endowed with neuroprotective effects. One hybrid was synthesized in four steps with 42% global yield, and the other hybrid in six steps with 19% global yield. The latter hybrid displayed moderate inhibitory activity against human acetylcholinesterase (hAChE) and greater activity against human butyrylcholinesterases (hBuChE). The selectivity for hBuChE was further rationalized by theoretical study. Importantly, the second hybrid showed a good antioxidant activity, exhibiting better ability in scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals than lipoic acid. Keywords: donepezil-lipoic acid hybrids, Alzheimer disease, multi-target directed ligands IntroductionAlzheimer disease (AD) is the most common cause of dementia in aging population. It was estimated that, in 2010, about 35.6 millions of people suffered from dementia worldwide, and it is expected that this number might triplicate in the next 40 years.1 Patients affected by AD experience progressive cognitive impairment, such as a decline in short-term memory, loss of speech, language and motor coordination. 2,3 AD is pathologically characterized by an extracellular deposition of β-amyloid (Aβ) peptide into senile plaques, intracellular formation of neurofibrillary tangles (NFTs) containing a hyperphosphorylated form of Tau protein, oxidative stress, mitochondrial abnormality, neuroinflammatory processes and neuronal loss, mainly affecting the frontal cortex and hippocampus. 4,5 AD is also characterized by a reduction of acetylcholine (ACh) levels, which is correlated with the cognitive symptoms. 6 The "cholinergic hypothesis", proposed in 1982 by Bartus et al.,7 postulated that the cognitive decline experienced by patients with AD resulted from a deficiency of acetylcholine or cholinergic neurotransmission. In humans, acetylcholine is degraded in the synaptic cleft by two main classes of cholinesterase enzymes: acetyl-(AChE) and butyryl- (BuChE) 8 cholinesterases. Near the amyloid plaques and neurofibrillary tangles, an extensive oxidative stress has been observed 9 which is a result of an altered balance of formation of reactive oxygen species (ROS) versus scavenging activity. 5,10 The production of ROS is also related to calcium homeostasis; the misbalance of calcium influx affects the mitochondrial Terra et al. 739 Vol. 29, No. 4, 2018 enzymes and ROS production is a normal part of the electron transport chain. However, excessive levels of these species damage proteins, lipids and nucleic acids. 9AD is a complex disease related to multiple pathogenic mechanisms involving different molecular targets. All the dru...

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Determination of free α-lipoic acid in foodstuffs by HPLC coupled with CEAD and ESI-MS

Cited by 53 publications

References 22 publications

Inositol and antioxidant supplementation: Safety and efficacy in pregnancy

Inositol and antioxidant supplementation: Safety and efficacy in pregnancy

Simultaneous Determination of the Endogenous Free α-Lipoic Acid and Dihydrolipoic Acid in Human Plasma and Erythrocytes by RP-HPLC with Electrochemical Detection

Two Novel Donepezil-Lipoic Acid Hybrids: Synthesis, Anticholinesterase and Antioxidant Activities and Theoretical Studies

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