|CAS number||(R) , (racemate)|
|Jmol-3D images||Image 1|
|Molar mass||206.33 g mol−1|
|Appearance||Yellow needle-like crystals|
|Solubility in water||Soluble as sodium salt|
|Solubility in ethanol||Soluble|
| (what is: / ?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Lipoic acid (LA), also known as α-lipoic acid and alpha lipoic acid (ALA) is an organosulfur compound derived from octanoic acid. LA contains two sulfur atoms (at C6 and C8) connected by a disulfide bond and is thus considered to be oxidized although either sulfur atom can exist in higher oxidation states. The carbon atom at C6 is chiral and the molecule exists as two enantiomers (R)-(+)-lipoic acid (RLA) and (S)-(-)-lipoic acid (SLA) and as a racemic mixture (R/S)-lipoic acid (R/S-LA). Only the (R)-(+)-enantiomer exists in nature and is an essential cofactor of four mitochondrial enzyme complexes. Endogenously synthesized RLA is essential for aerobic metabolism. Both RLA and R/S-LA are available as over-the-counter nutritional supplements and have been used nutritionally and clinically since the 1950s for various diseases and conditions. LA appears physically as a yellow solid and structurally contains a terminal carboxylic acid and a terminal dithiolane ring.
The relationship between endogenously synthesized (enzyme–bound) RLA and administered free RLA or R/S-LA has not been fully characterized but free plasma and cellular levels increase and decrease rapidly after oral consumption or intravenous injections. "Lipoate" is the conjugate base of lipoic acid, and the most prevalent form of LA under physiologic conditions. Although the intracellular environment is strongly reducing, both free LA and its reduced form, dihydrolipoic acid (DHLA), have been detected in cells after administration of LA. Most endogenously produced RLA is not “free” because octanoic acid, the precursor to RLA, is bound to the enzyme complexes prior to enzymatic insertion of the sulfur atoms. As a cofactor, RLA is covalently attached by an amide bond to a terminal lysine residue of the enzyme’s lipoyl domains. One of the most studied roles of RLA is as a cofactor of the pyruvate dehydrogenase complex (PDC or PDHC), though it is a cofactor in other enzymatic systems as well (described below).
Biosynthesis and attachment 
The precursor to lipoic acid, octanoic acid, is made via fatty acid biosynthesis in the form of octanoyl-acyl carrier protein. In eukaryotes, a second fatty acid biosynthetic pathway in mitochondria is used for this purpose. The octanoate is transferred from a thioester of acyl carrier protein to an amide of the lipoyl domain by an octanoyltransferase. The sulfur centers are inserted into the 6th and 8th carbons of octanoate via a radical SAM mechanism, by lipoyl synthase. The sulfurs are from the lipoyl synthase polypeptide. As a result, lipoic acid is synthesized on the lipoyl domain and no free lipoic acid is produced. Lipoic acid can be removed whenever proteins are degraded and by action of the enzyme lipoamidase. Free lipoate can be attached to the lipoyl domain by the enzyme lipoate protein ligase. The ligase activity of this enzyme requires ATP. Lipoate protein ligases proceed via an enzyme bound lipoyl adenylate intermediate.
Lipoic acid-dependent complexes 
2-OADH transfer reactions occur by a similar mechanism in the PDH complex, 2-oxoglutarate dehydrogenase (OGDH) complex, branched chain oxoacid dehydrogenase (BCDH) complex, and acetoin dehydrogenase (ADH) complex. The most studied of these is the PDH complex. These complexes have three central subunits: E1-3, which are the decarboxylase, lipoyl transferase, and dihydrolipoamide dehydrogenase respectively. These complexes have a central E2 core and the other subunits surround this core to form the complex. In the gap between these two subunits, the lipoyl domain ferries intermediates between the active sites. The geometry of the PDH E2 core is cubic in Gram-negative bacteria or dodecahedral in Eukaryotes and Gram-positive bacteria. Interestingly the 2-OGDH and BCDH geometry is always cubic. The lipoyl domain itself is attached by a flexible linker to the E2 core and the number of lipoyl domains varies from one to three for a given organism. The number of domains has been experimentally varied and seems to have little effect on growth until over nine are added, although more than three decreased activity of the complex. The lipoyl domains within a given complex are homogenous, while at least two major clusters of lipoyl domains exist in sequenced organisms.
Endogenous (enzyme-bound) (R)-lipoate also participates in transfer of acyl groups in the α-keto-glutarate dehydrogenase complex (KDHC or OGDC) and the branched-chain oxo acid dehydrogenase complex (BCOADC). RLA transfers a methylamine group in the glycine cleavage complex (GCV). RLA serves as co-factor to the acetoin dehydrogenase complex (ADC) catalyzing the conversion of acetoin (3-hydroxy-2-butanone) to acetaldehyde and acetyl coenzyme A, in some bacteria, allowing acetoin to be used as the sole carbon source.
The Glycine cleavage system differs from the other complexes, and has a different nomenclature. In this complex the H protein is a free lipoyl domain with additional helices, the L protein is a dihydrolipoamide dehydrogenase, the P protein is the decarboxylase, and the T protein transfers the methylamine from lipoate to tetrahydrofolate (THF) yielding methylene-THF and ammonia. Methylene-THF is then used by serine hydroxymethyltransferase (SHMT) to synthesize serine from glycine. This system is used by many organisms and plays a crucial role in the photosynthetic carbon cycle.
Biological sources and degradation 
Lipoic acid is present in almost all foods, but slightly more so in kidney, heart, liver, spinach, broccoli, and yeast extract. Naturally occurring lipoic acid is always covalently bound and not readily available from dietary sources. Additionally, the amount of lipoic acid present in dietary sources is very low. For instance, the purification of lipoic acid to determine its structure used an estimated 10 tons of liver residue, which yielded 30 mg of lipoic acid. As a result, all lipoic acid available as a supplement is chemically synthesized.
Baseline levels (prior to supplementation) of RLA and R-DHLA have not been detected in human plasma. RLA has been detected at 12.3−43.1 ng/mL following acid hydrolysis, which releases protein-bound lipoic acid. Enzymatic hydrolysis of protein bound lipoic acid released 1.4−11.6 ng/mL and <1-38.2 ng/mL using subtilisin and alcalase, respectively. It has not been determined whether pre-supplementation levels of RLA derive from food sources, mitochondrial turnover and salvaging or from gut microbes but low levels have been correlated to a variety of disease states.
Digestive proteolytic enzymes cleave the R-lipoyllysine residue from the mitochondrial enzyme complexes derived from food but are unable to cleave the (R)-lipoic acid-L-lysine amide bond. Both synthetic lipoamide and (R)-lipoyl-L-lysine are rapidly cleaved by serum lipoamidases which release free (R)-lipoic acid and either L-lysine or ammonia into the bloodstream. It is questionable whether food sources of RLA provide any measurable benefit nutritionally or therapeutically due to the very low concentrations present. Lipoate is the conjugate base of lipoic acid and as such is the most prevalent form under physiologic conditions. Most endogenous RLA is not "free" because octanaote is attached to the enzyme complexes that use it via LipA. The sulfur atoms derive from the amino acid L-cysteine and add asymmetrically to octanoate by lipoate synthase, thus generating the chiral center at C6. Endogenous RLA has been found outside the mitochondria associated with the nucleus, peroxisomes and other organelles. It has been suggested that the reduced form, R-DHLA may be the substrate for membrane-associated prostaglandin E-2 synthase (mPGES2).
Pharmacology and medical uses of free lipoic acid 
Today, R/S-LA and RLA are widely available as over-the-counter nutritional supplements in the United States in the form of capsules, tablets and aqueous liquids, and have been branded as antioxidants. This label has recently been challenged. In Japan, LA is marketed primarily as a "weight loss" and "energy" supplement. The relationships between supplemental doses and therapeutic doses have not been clearly defined. Because lipoic acid is not an essential nutrient, no Recommended Daily Allowance (RDA) has been established.
Possible beneficial effects 
Lipoic acid has been the subject of numerous research studies and clinical trials:
- Prevent organ dysfunction
- Treat or prevent cardiovascular disease
- Accelerate chronic wound healing
- Reduce iron overload
- Prevent migraines
- Treat chronic diseases associated with oxidative stress
- Reduce inflammation
- Treat peripheral artery disease.
||This section contains information of unclear or questionable importance or relevance to the article's subject matter. Please help improve this article by clarifying or removing superfluous information.|
Because of the low cost and ease of manufacturing R/S-LA relative to RLA, as well as early successes in treatments, the racemic form was more widely used nutritionally and clinically in Europe and Japan, despite the early recognition that the various forms of LA were not bioequivalent. The original rationale for using (R/S)-lipoic acid as a nutritional supplement was that endogenous RLA was known to have biochemical properties like a B-vitamin (acting as a substrate or cofactor essential for enzyme function). It was also recognized that lower endogenous concentrations of RLA were found in tissues of humans with various diseases, and lower levels of RLA were found in the 24 hour urine of patients with various diseases than in healthy subjects. Injections of R/S-LA as low as 10–25 mg normalized daily urinary output and, in many cases, improved patient health. When it was demonstrated that mammals have the genes to endogenously synthesize RLA, it lost vitamin status, but is today considered to be a “conditionally essential nutrient”. The exact mechanisms of how RLA levels decline with age and in various progressive diseases is unknown. In addition, microbial assays used to quantify LA were essentially stereospecific for RLA (100% active for RLA, 0% activity for SLA), so it was believed SLA was essentially inert or of very low biological activity. This was proven false by Gal, who demonstrated stereospecific toxicity of the (S)-enantiomer in thiamine-deficient rats.
RLA may function in vivo like a B-vitamin and at higher doses like plant-derived nutrients, such as curcumin, sulphoraphane, resveratrol, and other nutritional substances that induce phase II detoxification enzymes, thus acting as cytoprotective agents. This stress response indirectly improves the antioxidant capacity of the cell.
A recent human pharmacokinetic study of RLA demonstrated the maximum concentration in plasma and bioavailability are significantly greater than the free acid form, and rivals plasma levels achieved by intravenous administration of the free acid form. Additionally, high plasma levels comparable to those in animal models where Nrf2 was activated were achieved.
Adverse effects 
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Side effects of alpha lipoic acid may include headache, tingling or a "pins and needles" sensation, skin rash, or muscle cramps. There have been a few reports in Japan of a rare condition called insulin autoimmune syndrome in people using alpha lipoic acid. The condition causes hypoglycemia and antibodies directed against the body's own insulin without previous insulin therapy. The safety of alpha lipoic acid in pregnant or nursing women, children, or people with kidney or liver disease is unknown. The toxic dose in cats is much lower than that in humans or dogs  and produces hepatocellular toxicity.
Antioxidant and prooxidant effects of lipoic acid 
All of the disulfide forms of LA (R/S-LA, RLA and SLA) can be reduced to DHLA although both tissue specific and stereoselective (preference for one enantiomer over the other) reductions have been reported in model systems. At least two cytosolic enzymes, glutathione reductase (GR) and thioredoxin reductase (Trx1), and two mitochondrial enzymes, lipoamide dehydrogenase and thioredoxin reductase (Trx2), reduce LA. SLA is stereoselectively reduced by cytosolic GR whereas Trx1, Trx2 and lipoamide dehydrogenase stereoselectively reduce RLA. (R)-(+)-lipoic acid is enzymatically or chemically reduced to (R)-(-)-dihydrolipoic acid whereas (S)-(-)-lipoic acid is reduced to (S)-(+)-dihydrolipoic acid. Dihydrolipoic acid (DHLA) can also form intracellularly and extracellularly via non-enzymatic, thiol-disulfide exchange reactions.
The cytosolic and mitochondrial redox state is maintained in a reduced state relative to the extracellular matrix and plasma due to high concentrations of glutathione. Despite the strongly reducing milieu, LA has been detected intracellularly in both oxidized and reduced forms. Free LA is rapidly metabolized to a variety of shorter chain metabolites (via β-oxidation and either mono or bis-methylation) that have been identified and quantified intracellularly, in plasma and in urine.
The antioxidant effects of LA were demonstrated when it was found to prevent the symptoms of vitamin C and vitamin E deficiency. LA is reduced intracellularly to dihydrolipoic acid, which in cell culture regenerates by reduction of antioxidant radicals, such as vitamin C and vitamin E. LA is able to scavenge reactive oxygen and reactive nitrogen species in vitro due to long incubation times, but there is little evidence this occurs in vivo or that radical scavenging contributes to the primary mechanisms of action of LA. The relatively good scavenging activity of LA toward hypochlorous acid (a bactericidal produced by neutrophils that may produce inflammation and tissue damage) is due to the strained conformation of the 5-membered dithiolane ring, which is lost upon reduction to DHLA. In cells, LA is reduced to dihydrolipoic acid, which is generally regarded as the more bioactive form of LA and the form responsible for most of the antioxidant effects. This theory has been challenged due to the high level of reactivity of the two free sulfhydryls, low intracellular concentrations of DHLA as well as the rapid methylation of one or both sulfhydryls, rapid side chain oxidation to shorter metabolites and rapid efflux from the cell. Although both DHLA and LA have been found inside cells after administration, most intracellular DHLA probably exists as mixed disulfides with various cysteine residues from cytosolic and mitochondrial proteins. Recent findings suggest therapeutic and anti-aging effects are due to modulation of signal transduction and gene transcription, which improve the antioxidant status of the cell. Paradoxically, this likely occurs via pro-oxidant mechanisms, not by radical scavenging or reducing effects.
Metal chelation 
Owing to the presence of two thiol groups, dihydrolipoic acid is a chelating agent. It chelates both intracellular and extracellular mercury in the brain and in the body. Alpha Lipoic Acid (ALA) has a half life of 3 hours. Lipoic acid administration can significantly enhance biliary excretion of inorganic mercury in rat experiments, although it is not known if this is caused by chelation by lipoic acid or some other mechanism. Lipoic acid has the potential to cross the blood–brain barrier in humans, unlike DMSA and DMPS; its effectiveness, however, is heavily dependent on the dosage and frequency of application.
Medicinal differences between (R)-lipoic acid and (S)-lipoic acid 
RLA is essential for life and aerobic metabolism, and RLA is the form biosynthesized in humans and other organisms studied so far. SLA is produced in equal amounts with RLA during achiral manufacturing processes. The racemic form was more widely used clinically in Europe and Japan in the 1950s to 1960s despite the early recognition that the various forms of LA were not bioequivalent. The first synthetic procedures appeared for RLA and SLA in the mid 1950s. Advances in chiral chemistry led to more efficient technologies for manufacturing the single enantiomers by both classical resolution and asymmetric synthesis and the demand for RLA also grew at this time. In the 21st century, R/S-LA, RLA and SLA with high chemical and/or optical purities are available in industrial quantities. Currently most of the world supply of R/S-LA and RLA is manufactured in China and smaller amounts in Italy, Germany and Japan. RLA is produced by modifications of a process first described by Georg Lang in a Ph.D. thesis and later patented by DeGussa. Although RLA is favored nutritionally due to its “vitamin-like” role in metabolism, both RLA and R/S-LA are widely available as dietary supplements. Both stereospecific and non-stereospecific reactions are known to occur in vivo and contribute to the mechanisms of action but evidence to date indicates RLA may be the eutomer (the nutritionally and therapeutically preferred form).
SLA is generally considered safe and nontoxic. It has been shown to be more toxic to thiamine deficient rats, but the mechanism or implications of this are not clear. SLA did not exist prior to chemical synthesis in 1952. The (S)-enantiomer (SLA) can assist in the reduction of the RLA when a racemic (50% (R)-enantiomer and 50% (S)-enantiomer) mixture is given. Several studies have demonstrated that SLA either has lower activity than RLA or interferes with the specific effects of RLA by competitive inhibition.
Lipoic acid in vivo seems primarily to induce the oxidative stress response rather than directly scavenge free radicals (see above). This effect is specific for RLA. Very few studies compare individual enantiomers with racemic lipoic acid. It is unclear if twice as much racemic lipoic acid can replace RLA.
Clinical trials and approved uses 
RLA is being used in a federally funded clinical trial for multiple sclerosis at Oregon Health and Science University. (R)-Lipoic acid is currently being used in two federally funded clinical trials at Oregon State University to test its effects in preventing heart disease and atherosclerosis. Alpha-lipoic acid is approved in Germany as a drug for the treatment of polyneuropathies, such as diabetic and alcoholic polyneuropathies, and liver disease.
- Teichert J, Hermann R, Ruus P, Preiss R (November 2003). "Plasma kinetics, metabolism, and urinary excretion of alpha-lipoic acid following oral administration in healthy volunteers". J Clin Pharmacol 43 (11): 1257–67. doi:10.1177/0091270003258654. PMID 14551180.
- Petersen Shay, K, Moreau, RF, Smith, EJ, Hagen, TM (June 2008). "Is alpha-lipoic acid a scavenger of reactive oxygen species in vivo? Evidence for its initiation of stress signaling pathways that promote endogenous antioxidant capacity". IUBMB life 60 (6): 362–7. doi:10.1002/iub.40. PMID 18409172.
- Reljanovic M, Reichel G, Rett K, et al. (September 1999). "Treatment of diabetic polyneuropathy with the antioxidant thioctic acid (alpha-lipoic acid): a two year multicenter randomized double-blind placebo-controlled trial (ALADIN II). Alpha Lipoic Acid in Diabetic Neuropathy". Free Radic. Res. 31 (3): 171–9. PMID 10499773.
- Raddatz, G, Bisswanger, H (October 1997). "Receptor site and stereospecifity of dihydrolipoamide dehydrogenase for R- and S-lipoamide: a molecular modeling study". Journal of Biotechnology 58 (2): 89–100. doi:10.1016/S0168-1656(97)00135-1. PMID 9383983.
- Cronan JE, Fearnley IM, Walker JE. (2005). "Mammalian mitochondria contain a soluble acyl carrier protein". FEBS Lett. 579 (21): 4892–6. doi:10.1016/j.febslet.2005.07.077. PMID 16109413.
- Jordan SW, Cronan JE Jr. (1997). "A new metabolic link. The acyl carrier protein of lipid synthesis donates lipoic acid to the pyruvate dehydrogenase complex in Escherichia coli and mitochondria". J. Biol. Chem. 272 (29): 17903–6. doi:10.1074/jbc.272.29.17903. PMID 9218413.
- Cicchillo RM, Booker SJ. (2005). "Mechanistic investigations of lipoic acid biosynthesis in E. coli: both sulfur atoms in lipoic acid are contributed by the same lipoyl synthase polypeptide". J. Am. Chem. Soc. 127 (9): 2860–1. doi:10.1021/ja042428u. PMID 15740115.
- Jiang Y, Cronan JE. (2005). "Expression cloning and demonstration of Enterococcus faecalis lipoamidase (pyruvate dehydrogenase inactivase) as a Ser-Ser-Lys triad amidohydrolase". J. Biol. Chem. 280 (3): 2244–56. doi:10.1074/jbc.+M408612200. PMID 15528186.
- Cronan JE, Zhao X, Jiang Y. (2005). "Function, attachment and synthesis of lipoic acid in Escherichia coli". Adv. Microb. Physiol. 50: 103–46. doi:10.1016/S0065-2911(05)50003-1. PMID 16221579.
- Milne JL, Wu X, Borgnia MJ, Lengyel JS, Brooks BR, Shi D, Perham RN, Subramaniam S. (2006). "Molecular Structure of a 9-MDa Icosahedral Pyruvate Dehydrogenase Subcomplex Containing the E2 and E3 Enzymes Using Cryoelectron Microscopy". J. Biol. Chem. 281 (7): 4364–4370. doi:10.1074/jbc.+M504363200. PMC 1647297. PMID 16308322. 
- Murphy GE, Jensen GJ. (2005). "Electron cryotomography of the E. coli pyruvate and 2-oxoglutarate dehydrogenase complexes". Structure 13 (12): 1765–1773. doi:10.1016/j.str.2005.08.016. PMID 16338405. 
- Izard T, Aevarsson A, Allen MD, Westphal AH, Perham RN, de Kok A, Hol WG. (1999). "Principles of quasi-equivalence and Euclidean geometry govern the assembly of cubic and dodecahedral cores of pyruvate dehydrogenase complexes". Proc. Natl. Acad. Sci. USA 96 (4): 1240–1245. doi:10.1073/pnas.96.4.1240. PMC 15447. PMID 9990008. 
- Machado RS, Clark DP, and Guest JR (1992). "Construction and properties of pyruvate dehydrogenase complexes with up to nine lipoyl domains per lipoate acetyltransferase chain". FEMS Microbiol. Lett. 79 (1–3): 243–248. doi:10.1111/j.1574-6968.1992.tb05710.x. PMID 1478460.
- Omelchenko MV, Makarova KS, and Koonin EV (2002). "Recurrent intragenomic recombination leading to sequence homogenization during the evolution of the lipoyl-binding domain". J. FEMS Microbiol. Lett. 209 (2): 255–260. doi:10.1111/j.1574-6968.2002.tb11140.x.
- Douce R, Bourguignon J, Neuburger M, and Rebeille F (2001). "The glycine decarboxylase system: a fascinating complex". Trends Plant Sci. 6 (4): 167–176. doi:10.1016/S1360-1385(01)01892-1. PMID 11286922.
- Durrani, Arjumand I. Schwartz H, Nagl M, Sontag G. (Oct 2010). "Determination of free [alpha]-lipoic acid in foodstuffs by HPLC coupled with CEAD and ESI-MS". Food Chemistry 120 (4): 38329–36. doi:10.1016/j.foodchem.2009.11.045.
- Reed LJ (Oct 2001). "A Trail of Research from Lipoic Acid to alpha-Keto Acid Dehydrogenase Complexes". J. Biol. Chem. 276 (42): 38329–36. doi:10.1074/jbc.+R100026200. PMID 11477096.
- Hermann R, Niebch G, Borbe HO, Fieger H, Ruus P, Nowak H, Riethmuller-Winzen H, Peukert M, Blume H. (1996). "Enantioselective pharmacokinetics and bioavailability of different racemic formulations in healthy volunteers". Eur J Pharm Sci 4 (3): 167–174. doi:10.1016/0928-0987(95)00045-3.
- Teichert, J, Preiss, R (1997). "High-performance liquid chromatography methods for determination of lipoic and dihydrolipoic acid in human plasma". Methods in Enzymology. Methods in Enzymology 279: 159–66. doi:10.1016/S0076-6879(97)79019-0. ISBN 978-0-12-182180-7. PMID 9211267.
- Teichert, J, Preiss, R (October 1995). "Determination of lipoic acid in human plasma by high-performance liquid chromatography with electrochemical detection". Journal of Chromatography B 672 (2): 277–81. doi:10.1016/0378-4347(95)00225-8. PMID 8581134.
- Teichert, J, Preiss, R (November 1992). "HPLC-methods for determination of lipoic acid and its reduced form in human plasma". International Journal of Clinical Pharmacology, Therapy, and Toxicology 30 (11): 511–2. PMID 1490813.
- Baker, H, Deangelis, B, Baker, ER, Hutner, SH (September 1998). "A practical assay of lipoate in biologic fluids and liver in health and disease". Free Radical Biology & Medicine 25 (4–5): 473–9. doi:10.1016/S0891-5849(98)00087-2. PMID 9741583.
- Takenouchi, K, Aso, K, Kawashima, S (June 1962). "Studies on the metabolism of thioctic acid in skin diseases. II. Loading test of thioctic acid in various skin diseases". Journal of Vitaminology 8: 99–114. PMID 13984665.
- Wada, M, Shigeta, Y, Inamori, K (September 1961). "A study on the metabolism of lipoic acid and lipoamide". Journal of Vitaminology 7: 237–42. PMID 14004240.
- Shigeta Y, Hiraizumi G, Wada M, Oji K, Yoshida T. Study on the Serum Level of Thioctic Acid in Patients with Various Diseases. J Vitaminology. (1961) 7:48-52
- Biewenga, GP, Haenen, GR, Bast, A (September 1997). "The pharmacology of the antioxidant lipoic acid". General Pharmacology 29 (3): 315–31. doi:10.1016/S0306-3623(96)00474-0. PMID 9378235.
- Oizumi, J, Hayakawa, K (July 1989). "Liberation of lipoate by human serum lipoamidase from bovine heart pyruvate dehydrogenase". Biochemical and Biophysical Research Communications 162 (2): 658–63. doi:10.1016/0006-291X(89)92361-9. PMID 2502979.
- Saito J (1960). "The Conversion of Thioctamide to Thioctic acid in Biological Systems. I. The thioctic Active Substances in Rabbit Serum after Administration of Thioctamide". Vitamin 21 (3): 359–63.
- Backman-Gullers, B, Hannestad, U, Nilsson, L, Sorbo, B (October 1990). "Studies on lipoamidase: characterization of the enzyme in human serum and breast milk". Clinica Chimica Acta 191 (1–2): 49–60. doi:10.1016/0009-8981(90)90057-Y. PMID 2127386.
- Garganta, CL, Wolf, B (August 1990). "Lipoamidase activity in human serum is due to biotinidase". Clinica Chimica Acta 189 (3): 313–25. doi:10.1016/0009-8981(90)90313-H. PMID 2225462.
- Shay, KP, Moreau, RF, Smith, EJ, Smith, AR, Hagen, TM (October 2009). "Alpha-lipoic acid as a dietary supplement: Molecular mechanisms and therapeutic potential". Biochimica et Biophysica Acta 1790 (10): 1149–60. doi:10.1016/j.bbagen.2009.07.026. PMC 2756298. PMID 19664690.
- Packer & Patel 2008, Nesbitt NM, Cicchillo RM, Lee KH, Grove TL, Booker SJ. Ch. 2 "Lipoic Acid Biosynthesis"
- Mascitelli-Coriandoli, E, Citterio, C (November 1959). "Intracellular thioctic acid and coenzyme A following vanadium treatment". Nature 184 (4699): 1641. doi:10.1038/1841641a0. PMID 14421987.
- Marchesini, S, Poirier, Y (August 2003). "Futile cycling of intermediates of fatty acid biosynthesis toward peroxisomal beta-oxidation in Saccharomyces cerevisiae". Journal of Biological Chemistry 278 (35): 32596–601. doi:10.1074/jbc.M305574200. PMID 12819196.
- Watanabe, K, Ohkubo, H, Niwa, H, Tanikawa, N, Koda, N, Ito, S, Ohmiya, Y (June 2003). "Essential 110Cys in active site of membrane-associated prostaglandin E synthase-2". Biochemical and Biophysical Research Communications 306 (2): 577–81. doi:10.1016/S0006-291X(03)01025-8. PMID 12804604.
- Alpha Lipoic Acid C8H14O2S2 206.33
- Gianturco, V, Bellomo, A, D'ottavio, E, Formosa, V, Iori, A, Mancinella, M, Troisi, G, Marigliano, V (2009). "Impact of therapy with alpha-lipoic acid (ALA) on the oxidative stress in the controlled NIDDM: a possible preventive way against the organ dysfunction?". Archives of gerontology and geriatrics 49 (Suppl 1): 129–33. doi:10.1016/j.archger.2009.09.022. PMID 19836626.
- Morcos, M, Borcea, V, Isermann, B, Gehrke, S, Ehret, T, Henkels, M, Schiekofer, S, Hofmann, M et al. (June 2001). "Effect of alpha-lipoic acid on the progression of endothelial cell damage and albuminuria in patients with diabetes mellitus: an exploratory study". Diabetes research and clinical practice 52 (3): 175–83. doi:10.1016/S0168-8227(01)00223-6. PMID 11323087.
- Vossler, S, Füllert, S, Schneider, F, Haak, E, Haak, T, Samigullin, R, Tritschler, H, Tooke, JE et al. (July 2007). "Pharmacodynamic effects of orally administered dexlipotam on endothelial function in type 2-diabetic patients". International journal of clinical pharmacology and therapeutics 45 (7): 385–93. PMID 17725245.
- Ghibu, S, Richard, C, Vergely, C, Zeller, M, Cottin, Y, Rochette, L (November 2009). "Antioxidant properties of an endogenous thiol: Alpha-lipoic acid, useful in the prevention of cardiovascular diseases". Journal of cardiovascular pharmacology 54 (5): 391–8. doi:10.1097/FJC.0b013e3181be7554. PMID 19998523.
- Alleva, R, Nasole, E, Di Donato, F, Borghi, B, Neuzil, J, Tomasetti, M (July 2005). "alpha-Lipoic acid supplementation inhibits oxidative damage, accelerating chronic wound healing in patients undergoing hyperbaric oxygen therapy". Biochemical and Biophysical Research Communications 333 (2): 404–10. doi:10.1016/j.bbrc.2005.05.119. PMID 15950945.
- Chang, JW, Lee, EK, Kim, TH, Min, WK, Chun, S, Lee, KU, Kim, SB, Park, JS (2007). "Effects of alpha-lipoic acid on the plasma levels of asymmetric dimethylarginine in diabetic end-stage renal disease patients on hemodialysis: a pilot study". American journal of nephrology 27 (1): 70–4. doi:10.1159/000099035. PMID 17259696.
- Femiano, F, Scully, C, Gombos, F (December 2002). "Idiopathic dysgeusia; an open trial of alpha lipoic acid (ALA) therapy". International journal of oral and maxillofacial surgery 31 (6): 625–8. doi:10.1054/ijom.2002.0276. PMID 12521319.
- Femiano, F, Scully, C (May 2002). "Burning mouth syndrome (BMS): double blind controlled study of alpha-lipoic acid (thioctic acid) therapy". Journal of Oral Pathology & Medicine 31 (5): 267–9. doi:10.1034/j.1600-0714.2002.310503.x. PMID 12110042.
- Patton, LL, Siegel, MA, Benoliel, R, De Laat, A (March 2007). "Management of burning mouth syndrome: systematic review and management recommendations". Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics 103 (Suppl): S39.e1–13. doi:10.1016/j.tripleo.2006.11.009. PMID 17379153.
- Kundiev, IuI, Lubianova, IP, Mikhaĭlik, OM, Dudchenko, NO, Lampeka, EG (2001). "Berlition R 300 oral -- alpha-lipoic acid preparation for the correction of body changes associated with high serum iron content". Meditsina truda i promyshlennaia ekologiia (1): 14–8. PMID 11221104.
- Sola, S, Mir, MQ, Cheema, FA, Khan-Merchant, N, Menon, RG, Parthasarathy, S, Khan, BV (January 2005). "Irbesartan and lipoic acid improve endothelial function and reduce markers of inflammation in the metabolic syndrome: results of the Irbesartan and Lipoic Acid in Endothelial Dysfunction (ISLAND) study". Circulation 111 (3): 343–8. doi:10.1161/01.CIR.0000153272.48711.B9. PMID 15655130.
- Minokoshi, Y, Alquier, T, Furukawa, N, Kim, YB, Lee, A, Xue, B, Mu, J, Foufelle, F et al. (April 2004). "AMP-kinase regulates food intake by responding to hormonal and nutrient signals in the hypothalamus". Nature 428 (6982): 569–74. doi:10.1038/nature02440. PMID 15058305.
- Ying, Z, Kherada, N, Farrar, B, Kampfrath, T, Chung, Y, Simonetti, O, Deiuliis, J, Desikan, R et al. (January 2010). "Lipoic acid effects on established atherosclerosis". Life Sciences 86 (3–4): 95–102. doi:10.1016/j.lfs.2009.11.009. PMC 3075920. PMID 19944706.
- Liu, J (January 2008). "The effects and mechanisms of mitochondrial nutrient alpha-lipoic acid on improving age-associated mitochondrial and cognitive dysfunction: an overview". Neurochemical research 33 (1): 194–203. doi:10.1007/s11064-007-9403-0. PMID 17605107.
- Packer, L, Tritschler, HJ, Wessel, K (1997). "Neuroprotection by the metabolic antioxidant alpha-lipoic acid". Free radical biology & medicine 22 (1–2): 359–78. doi:10.1016/S0891-5849(96)00269-9. PMID 8958163.
- Holmquist, L, Stuchbury, G, Berbaum, K, Muscat, S, Young, S, Hager, K, Engel, J, Münch, G (January 2007). "Lipoic acid as a novel treatment for Alzheimer's disease and related dementias". Pharmacology & therapeutics 113 (1): 154–64. doi:10.1016/j.pharmthera.2006.07.001. PMID 16989905.
- Hager, K, Kenklies, M, McAfoose, J, Engel, J, Münch, G (2007). "Alpha-lipoic acid as a new treatment option for Alzheimer's disease—a 48 months follow-up analysis". Journal of neural transmission. Supplementum (72): 189–93. PMID 17982894.
- MacZurek, A, Hager, K, Kenklies, M, Sharman, M, Martins, R, Engel, J, Carlson, DA, Münch, G (2008). "Lipoic acid as an anti-inflammatory and neuroprotective treatment for Alzheimer's disease". Advanced drug delivery reviews 60 (13–14): 1463–70. doi:10.1016/j.addr.2008.04.015. PMID 18655815.
- Hurdag, C, Ozkara, H, Citci, S, Uyaner, I, Demirci, C (2005). "The effects of alpha-lipoic acid on nitric oxide synthetase dispersion in penile function in streptozotocin-induced diabetic rats". International journal of tissue reactions 27 (3): 145–50. PMID 16372481.
- Yao, LS, Wang, YT, Chen, Y, Dai, YT (October 2009). "Expressions of NOS isoforms in the cavernous tissues of diabetic rat models". Zhonghua nan ke xue = National journal of andrology 15 (10): 915–9. PMID 20112741.
- Magis, D, Ambrosini, A, Sándor, P, Jacquy, J, Laloux, P, Schoenen, J (January 2007). "A randomized double-blind placebo-controlled trial of thioctic acid in migraine prophylaxis". Headache 47 (1): 52–7. doi:10.1111/j.1526-4610.2006.00626.x. PMID 17355494.
- Yadav, V, Marracci, G, Lovera, J, Woodward, W, Bogardus, K, Marquardt, W, Shinto, L, Morris, C et al. (April 2005). "Lipoic acid in multiple sclerosis: a pilot study". Multiple sclerosis (Houndmills, Basingstoke, England) 11 (2): 159–65. doi:10.1191/1352458505ms1143oa. PMID 15794388.
- Salinthone, S, Yadav, V, Bourdette, DN, Carr, DW (June 2008). "Lipoic acid: a novel therapeutic approach for multiple sclerosis and other chronic inflammatory diseases of the CNS". Endocrine, metabolic & immune disorders drug targets 8 (2): 132–42. doi:10.2174/187153008784534303. PMID 18537699.
- Yadav, V, Marracci, GH, Munar, MY, Cherala, G, Stuber, LE, Alvarez, L, Shinto, L, Koop, DR et al. (April 2010). "Pharmacokinetic study of lipoic acid in multiple sclerosis: comparing mice and human pharmacokinetic parameters". Multiple sclerosis (Houndmills, Basingstoke, England) 16 (4): 387–97. doi:10.1177/1352458509359722. PMID 20150394.
- Smith, AR, Shenvi, SV, Widlansky, M, Suh, JH, Hagen, TM (May 2004). "Lipoic acid as a potential therapy for chronic diseases associated with oxidative stress". Current medicinal chemistry 11 (9): 1135–46. PMID 15134511.
- Zhang WJ, Wei H, Hagen T, Frei B (2007). "α-Lipoic acid attenuates LPS-induced inflammatory responses by activating the phosphoinositide 3-kinase/Akt signaling pathway". Proc Natl Acad Sci U S A. 104 (10): 4077–82. doi:10.1073/pnas.0700305104. PMC 1805485. PMID 17360480.
- Vasdev, S, Gill, V, Singal, P (2007). "Role of advanced glycation end products in hypertension and atherosclerosis: therapeutic implications". Cell biochemistry and biophysics 49 (1): 48–63. doi:10.1007/s12013-007-0039-0. PMID 17873339.
- Vincent, HK, Bourguignon, CM, Vincent, KR, Taylor, AG (June 2007). "Effects of alpha-lipoic acid supplementation in peripheral arterial disease: a pilot study". Journal of alternative and complementary medicine 13 (5): 577–84. doi:10.1089/acm.2007.6177. PMID 17604563.
- Kleeman A, Borbe HO, Ulrich H. Thioctic Acid-Lipoic Acid; in Thioctic Acid. New Biochemistry, Pharmacology and Findings from Clinical Practice with Thioctic Acid. 11-26. Borbe; Ulrich (Hrsg.) Verfasser: Reschke, Barbara ; Borbe, Harald [Hrsg.]Verleger: [Frankfurt (Main)] : pmi (1991)
- Hiraizumi G (1959). "Alpha Lipoic Acid Metabolism in Various Diseases. II. The Urinary Excretion and Serum level of Alpha Lipoic Acid in Patients with Various Diseases". Bitamin 18 (1): 184–8.
- Wada M, Hiraizumi G, Shigeta Y (1960). "The Urinary Excretion and Serum Level of a-lipoic acid in Patients with Several Diseases". Maikurobaioassei (Microbioassay) 1: 53–5.
- Gal, EM, Razevska, DE (August 1960). "Studies on the in vivo metabolism of lipoic acid. 1. The fate of DL-lipoic acid-S35 in normal and thiamine-deficient rats". Archives of biochemistry and biophysics 89 (2): 253–61. doi:10.1016/0003-9861(60)90051-5. PMID 13825981.
- Gal, EM (July 1965). "Reversal of selective toxicity of (-)-alpha-lipoic acid by thiamine in thiamine-deficient rats". Nature 207 (996): 535. doi:10.1038/207535a0. PMID 5328673.
- Lecoq, R, Chauchard, P, Mazoue, H (October 1958). "Comparative chronaxymetric research on the effects of several vitaminic substances (stigmasterol, carnitine, thioctic acid)". Comptes rendus hebdomadaires des séances de l'Académie des sciences 247 (17): 1411–3. PMID 13609011.
- McCarty, MF (April 1981). "Toward a "bio-energy supplement" -- a prototype for functional orthomolecular supplementation". Medical hypotheses 7 (4): 515–38. doi:10.1016/0306-9877(81)90038-4. PMID 6793816.
- Lykkesfeldt J, Hagen TM, Vinarsky V, Ames BN (Sep 1998). "Age-associated decline in ascorbic acid concentration, recycling, and biosynthesis in rat hepatocytes--reversal with (R)-alpha-lipoic acid supplementation". FASEB J. 12 (12): 1183–9. PMID 9737721.
- Hagen, TM, Ingersoll, RT, Lykkesfeldt, J, Liu, J, Wehr, CM, Vinarsky, V, Bartholomew, JC, Ames, AB (February 1999). "(R)-alpha-lipoic acid-supplemented old rats have improved mitochondrial function, decreased oxidative damage, and increased metabolic rate". The FASEB journal : official publication of the Federation of American Societies for Experimental Biology 13 (2): 411–8. PMID 9973329.
- Hagen, TM, Vinarsky, V, Wehr, CM, Ames, BN (2000). "(R)-alpha-lipoic acid reverses the age-associated increase in susceptibility of hepatocytes to tert-butylhydroperoxide both in vitro and in vivo". Antioxidants & redox signaling 2 (3): 473–83. doi:10.1089/15230860050192251. PMID 11229361.
- Hagen, TM, Liu, J, Lykkesfeldt, J, Wehr, CM, Ingersoll, RT, Vinarsky, V, Bartholomew, JC, Ames, BN (February 2002). "Feeding acetyl-l-carnitine and lipoic acid to old rats significantly improves metabolic function while decreasing oxidative stress". Proceedings of the National Academy of Sciences of the United States of America 99 (4): 1870–5. doi:10.1073/pnas.261708898. PMC 122286. PMID 11854487.
- Liu, J; Head, E; Gharib, AM; Yuan, W; Ingersoll, RT; Hagen, TM; Cotman, CW; Ames, BN (2002). "Memory loss in old rats is associated with brain mitochondrial decay and RNA/DNA oxidation: Partial reversal by feeding acetyl-l-carnitine and/or R-α-lipoic acid". Proceedings of the National Academy of Sciences of the United States of America 99 (4): 2356–61. doi:10.1073/pnas.261709299. PMC 122369. PMID 11854529. Erratum in: Proc Natl Acad Sci U S A 2002 May 14;99(10):7184-5
- Packer & Patel 2008, Petersen-Shay K, Shenvi S, Hagen TM. Ch. 14 "Lipoic acid as an inducer of phase II detoxification enzymes through activation of Nr-f2 dependent gene expression." pp. 349–371
- Lii CK, Liu KL, Cheng YP, Lin AH, Chen HW, Tsai CW (May 2010). "Sulforaphane and alpha-lipoic acid upregulate the expression of the pi class of glutathione S-transferase through c-jun and Nrf2 activation". J. Nutr. 140 (5): 885–92. doi:10.3945/jn.110.121418. PMID 20237067.
- Carlson, DA, Smith, AR, Fischer, SJ, Young, KL, Packer, L (December 2007). "The plasma pharmacokinetics of R-(+)-lipoic acid administered as sodium R-(+)-lipoate to healthy human subjects". Alternative medicine review : a journal of clinical therapeutic 12 (4): 343–51. PMID 18069903.
- Hill AS et al., J Anim Physiol Anim Nutr (Berl.), 2004 Apr;88(3-4):150-6
- Arnér, ES, Nordberg, J, Holmgren, A (August 1996). "Efficient reduction of lipoamide and lipoic acid by mammalian thioredoxin reductase". Biochemical and Biophysical Research Communications 225 (1): 268–74. doi:10.1006/bbrc.1996.1165. PMID 8769129.
- Biaglow, JE, Ayene, IS, Koch, CJ, Donahue, J, Stamato, TD, Mieyal, JJ, Tuttle, SW (April 2003). "Radiation response of cells during altered protein thiol redox". Radiation research 159 (4): 484–94. doi:10.1667/0033-7587(2003)159[0484:RROCDA]2.0.CO;2. PMID 12643793.
- Haramaki, N, Han, D, Handelman, GJ, Tritschler, HJ, Packer, L (1997). "Cytosolic and mitochondrial systems for NADH- and NADPH-dependent reduction of alpha-lipoic acid". Free radical biology & medicine 22 (3): 535–42. doi:10.1016/S0891-5849(96)00400-5. PMID 8981046.
- Constantinescu, A, Pick, U, Handelman, GJ, Haramaki, N, Han, D, Podda, M, Tritschler, HJ, Packer, L (July 1995). "Reduction and transport of lipoic acid by human erythrocytes". Biochemical pharmacology 50 (2): 253–61. doi:10.1016/0006-2952(95)00084-D. PMID 7632170.
- May, JM, Qu, ZC, Nelson, DJ (June 2006). "Cellular disulfide-reducing capacity: an integrated measure of cell redox capacity". Biochemical and Biophysical Research Communications 344 (4): 1352–9. doi:10.1016/j.bbrc.2006.04.065. PMID 16650819.
- Jones, W, Li, X, Qu, ZC, Perriott, L, Whitesell, RR, May, JM (July 2002). "Uptake, recycling, and antioxidant actions of alpha-lipoic acid in endothelial cells". Free radical biology & medicine 33 (1): 83–93. doi:10.1016/S0891-5849(02)00862-6. PMID 12086686.
- Schempp H, Ulrich H, Elstner EF (1994). "Stereospecific reduction of R(+)-thioctic acid by porcine heart lipoamide dehydrogenase/diaphorase". Z. Naturforsch., C, J. Biosci. 49 (9-10): 691–2. PMID 7945680.
- Biewenga G Ph, Haenen GRMM, Bast A (1997). "Ch. 1 "An overview of Lipoate Chemistry"". In Fuchs J, Packer L, Zimmer G. Lipoic Acid In Health & Disease. Marcel Dekker. pp. 1–32.
- Sen CK (1997). "Nutritional Biochemistry of Cellular Glutathione". Nutritional Biochemistry 8 (12): 660–672. doi:10.1016/S0955-2863(97)00113-7.
- Marí, M, Morales, A, Colell, A, García-Ruiz, C, Fernández-Checa, JC (November 2009). "Mitochondrial Glutathione, a Key Survival Antioxidant". Antioxidants & redox signaling 11 (11): 2685–700. doi:10.1089/ARS.2009.2695. PMC 2821140. PMID 19558212.
- Packer, L, Witt, EH, Tritschler, HJ (August 1995). "alpha-Lipoic acid as a biological antioxidant". Free radical biology & medicine 19 (2): 227–50. doi:10.1016/0891-5849(95)00017-R. PMID 7649494.
- Harrison, EH, McCormick, DB (February 1974). "The metabolism of dl-(1,6-14C)lipoic acid in the rat". Archives of biochemistry and biophysics 160 (2): 514–22. doi:10.1016/0003-9861(74)90428-7. PMID 4598618.
- Schupke, H, Hempel, R, Peter, G, Hermann, R, Wessel, K, Engel, J, Kronbach, T (June 2001). "New metabolic pathways of alpha-lipoic acid". Drug metabolism and disposition: the biological fate of chemicals 29 (6): 855–62. PMID 11353754.
- Rosenberg, H (1959). "Effect of ?-lipoic acid on vitamin C and vitamin E deficiencies". Archives of Biochemistry and Biophysics 80: 86–93. doi:10.1016/0003-9861(59)90345-5.
- Haenen, GRMM, Bast, A (1991). "Scavenging of hypochlorous acid by lipoic acid". Biochem Pharmacol 42 (11): 2244–6. doi:10.1016/0006-2952(91)90363-A. PMID 1659823.
- Packer & Patel 2008, Carlson DA, Young KL, Fischer SJ, Ulrich H. Ch. 10 "An Evaluation of the Stability and Pharmacokinetics of R-lipoic Acid and R-Dihydrolipoic Acid Dosage Forms in Plasma from Healthy Human Subjects." pp. 235–270
- Gregus, Z.; Stein, A.F, Varga, F., Klaassen, C.D. (1992). "Effect of lipoic acid on biliary excretion of glutathione and metals". Toxicology and Applied Pharmacology 114 (1): 88–96. doi:10.1016/0041-008X(92)90100-7. PMID 1585376.
- Rooney, James, (2007). "The role of thiols, dithiols, nutritional factors and interacting ligands in the toxicology of mercury". Toxicology 234 (3): 145–156. doi:10.1016/j.tox.2007.02.016. PMID 17408840.
- Fontanella, L (1955). "Preparation of optical antipodes of alpha-lipoic acid". Il Farmaco; edizione scientifica 10 (12): 1043–5. PMID 13294188.
- Walton E, Wagner AF, Bachelor FW, Peterson LH, Holly FW, Folkers K (1955). "Synthesis of (+)-Lipoic Acid and its Optical Antipode". J. Am. Chem. Soc. 77 (19): 5144–9. doi:10.1021/ja01624a057.
- Acker DS, Wayne WJ. (1957). "Optically Active and Radioactive α-Lipoic Acids". J. Am. Chem. Soc. 79: 6483. doi:10.1021/ja01581a033.
- Deguchi, Y, Miura, K (June 1964). "Studies on the Synthesis of Thioctic acid and its related compounds. XIV. Synthesis of (+)-Thioctamide". Yakugaku Zasshi 84: 562–3. PMID 14207116.
- Lang G. In Vitro Metabolism of a-Lipoic Acid Especially Taking Enantioselective Bio-transformation into Account. Ph.D. Thesis, University of Münster, Münster,Germany (1992)
- Blaschke et al. Preparation and use of salts of the pure enantiomers of alpha-lipoic acid. US 5281722 (Jan 25, 1994)
- Packer, L, Kraemer, K, Rimbach, G (October 2001). "Molecular aspects of lipoic acid in the prevention of diabetes complications". Nutrition (Burbank, Los Angeles County, Calif.) 17 (10): 888–95. doi:10.1016/S0899-9007(01)00658-X. PMID 11684397.
- Hornberger CS, Heitmiller RF, Gunsalus IC, Schnakenberg GHF, Reed LJ (1953). "Synthesis of DL—Lipoic Acid". J. Am. Chem. Soc. 75 (6): 1273–7. doi:10.1021/ja01102a003.
- Hornberger CS, Heitmiller RF, Gunsalus IC, Schnakenberg GHF, Reed LJ (1952). "Synthetic Preparation of Lipoic Acid". J. Am. Chem. Soc. 74 (9): 2382. doi:10.1021/ja01129a511.
- Biewenga GP, Haenen GRMM, Groen BH, Biewenga JE, Van Grondelle R, Bast A (1997). "Combined non-enzymatic and enzymatic reduction favors bioactivation of racemic lipoic acid: an advantage of a racemic drug?". Chirality 9: 362–6.
- Ulrich H, Weischer CH, Engel J, Hettche H. Pharmaceutical compositions containing R-alpha-lipoic acid or S-alpha.-lipoic acid as active ingredient. US 6,271,254 2001
- Kilic, F, Handelman, GJ, Serbinova, E, Packer, L, Trevithick, JR (October 1995). "Modelling cortical cataractogenesis 17: in vitro effect of a-lipoic acid on glucose-induced lens membrane damage, a model of diabetic cataractogenesis". Biochemistry and molecular biology international 37 (2): 361–70. PMID 8673020.
- Artwohl M, Schmetterer L, Rainer G, et al. Modulation by antioxidants of endothelial apoptosis, proliferation, & associated gene/protein expression. European Association for the Study of Diabetes. Program 36. Jerusalem, Israel; 2000: Abs 274
- Streeper, RS, Henriksen, EJ, Jacob, S, Hokama, JY, Fogt, DL, Tritschler, HJ (July 1997). "Differential effects of lipoic acid stereoisomers on glucose metabolism in insulin-resistant skeletal muscle". The American journal of physiology 273 (1 Pt 1): E185–91. PMID 9252495.
- Frölich, L, Götz, ME, Weinmüller, M, Youdim, MB, Barth, N, Dirr, A, Gsell, W, Jellinger, K et al. (March 2004). "(r)-, but not (s)-alpha lipoic acid stimulates deficient brain pyruvate dehydrogenase complex in vascular dementia, but not in Alzheimer dementia". Journal of neural transmission (Vienna, Austria : 1996) 111 (3): 295–310. doi:10.1007/s00702-003-0043-5. PMID 14991456.
- ClinicalTrials.gov NCT00676156 A Study of the Pharmacokinetics and Immunologic Effects of Lipoic Acid in Multiple Sclerosis
- ClinicalTrials.gov NCT00765310 Lipoic Acid and Prevention of Heart Disease
- ClinicalTrials.gov NCT00764270 The Role of R-Alpha Lipoic Acid in the Treatment of Atherosclerotic Vascular Disease
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|Wikimedia Commons has media related to: lipoic acid|
- Jane Higdon, "Lipoic Acid", Micronutrient Information Center, Linus Pauling Institute, Oregon State University
- Packer, Lester; Patel, Mulchand S., eds. (2008). Lipoic acid: energy production, antioxidant activity and health effects. Boca Raton: CRC Press. ISBN 1-4200-4537-7.