Grundinformationen
- CAS
1077-28-7- Standard-SMILES
O=C(O)CCCCC1CCSS1- InChIKey
AGBQKNBQESQNJD-UHFFFAOYSA-N- Summenformel
- C8H14O2S2
- Durchschnittliche Molmasse
- 206,3 g/mol
- Monoisotopische Masse
- 206,04352169
Überblick
Lipoic acid is a heterocyclic thia fatty acid comprising pentanoic acid with a 1,2-dithiolan-3-yl group at the 5-position. It has a role as a geroprotector and a fundamental metabolite. It is a member of dithiolanes, a heterocyclic fatty acid and a thia fatty acid. It is functionally related to an octanoic acid. It is a conjugate acid of a lipoate.
Namen und Bezeichner
- Bevorzugter Name
- alpha Lipoic acid
- IUPAC
- 5-(dithiolan-3-yl)pentanoic acid
- Lokaler Name
- 5-(Dithiolan-3-yl)valeriansaeure
- Englischer Name
- α-Lipoic Acid
- Summenformel
- C8H14O2S2
- Molmasse
- 206.33
Namen und Synonyme
Weitere Namen anzeigen
Datenbank-Bezeichner
- CAS
1077-28-7、1200-22-2、62-46-4- PubChem CID
- 864
- DTXSID
DTXSID7025508- ChEMBL
CHEMBL134342、CHEMBL33864- ChEBI
CHEBI:16494- UNII
- 73Y7P0K73Y
- EC Number
- 200-534-6、214-071-2
- Nikkaji
- J38.321J
Eigenschaften
Berechnete Struktureigenschaften
- XLogP
- 1,7
- Polarare Oberfläche (TPSA)
- 87,9 Ų
- H-Brücken-Donoren
- 1
- H-Brücken-Akzeptoren
- 4
- Frei drehbare Bindungen
- 5
- Schwere Atome
- 12
- Formalladung
- 0
- Komplexität
- 150
Experimentelle und physikochemische Eigenschaften
Solubility
Yellow powder; solubility in ethanol: 50 mg/mL /Synthetic, oxidized form/
Soluble in methanol, ethanol, diethyl ether and chloroform
Other Experimental Properties
White powder, soluble in water, pH of aqueous solutions about 7.4 /Thioctic acid, sodium salt/
Crystals by vacuum sublimation (at 85-90 °C and 25 micron). MP: 46-48 °C (microblock). Specific optical rotation: + 104 deg at 23 °C/D (c = 0.88 in benzene). UV max (methanol): 333 nm (epsilon 150). pKa = 5.4. Practically insoluble in water. Soluble in fat solvents. /Thioctic acid, d-form/
Yellow needles from cyclohexane. MP: 60-61 °C. BP: 160-165 °C. Practically insoluble in water; soluble in fat solvents. Forms a water-soluble sodium salt. /Thioctic acid, dl-form/
Crystals from cyclohexane. MP: 45-47.5 °C (microblock). Specific optical rotation: -113 deg at 23 °C/D (c = 1.88 in benzene). UV max (methanol): 330 nm (epsilon 140). /Thioctic acid, l-form/
Physikochemische Eigenschaften
- Schmelzpunkt
- 60 · 60-62 °C
- Siedepunkt
- 160 · 160-165 °C(lit.)
- Dichte
- 1.2888 · 1.2888 (rough estimate)
- Brechungsindex
- 1.52 · 1.5200 (estimate)
- Flammpunkt
- 160 · 160-165°C
- storage temp.
- 2 · 2-8°C
- Löslichkeit
- 50 mg/mL · ethanol: 50 mg/mL
- pka
- 4.75 · 4.75±0.10(Predicted)
- Aggregatzustand
- Crystals or Crystalline Powder
- Farbe
- Yellow
- Biologische Quelle
- synthetic
- Wasserlöslichkeit
- 0.9 g/L · 0.9 g/L (20 ºC)
- Merck
- 14 · 14,9326
- BRN
- 81853 · 81853
- Stabilität
- Stable. Incompatible with strong oxidizing agents.
- Kosmetik-Inhaltsstoffe Funktionen
- ANTIOXIDANT
- InChI
- 1S/C8H14O2S2/c9-8(10)4-2-1-3-7-5-6-11-12-7/h7H,1-6H2,(H,9,10)
- InChIKey
- AGBQKNBQESQNJD-UHFFFAOYSA-N
- SMILES
- OC(=O)CCCCC1CCSS1
- LogP
- 2.53 · 2.530 (est)
- CAS Datenbank
- 1077 · 1077-28-7(CAS DataBase Reference)
- NIST chemische Informationen
- Dl-thioctic acid(1077-28-7)
Sicherheit und Regulatorisches
GHS-Klassifizierung
GHS Classification
This chemical does not meet GHS hazard criteria for 6.5% (28 of 430) of reports.
Warning
H302 (93.5%): Harmful if swallowed [Warning Acute toxicity, oral]
P261, P264, P264+P265, P270, P272, P273, P280, P301+P317, P302+P352, P305+P351+P338, P321, P330, P332+P317, P333+P317, P337+P317, P362+P364, P391, and P501 (click each P-code to see the statement)
Aggregated GHS information provided per 430 reports by companies from 16 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.
This chemical does not meet GHS hazard criteria for 42.3% (52 of 123) of reports.
Gefahrenhinweise
Regulatory Information
Chemical: 1,2-Dithiolane-3-pentanoic acid
Status: Active Update: 22-07-2021 https://echa.europa.eu/registration-dossier/-/registered-dossier/22716
1,2-Dithiolane-3-pentanoic acid: Does not have an individual approval but may be used under an appropriate group standard
Hazard Classes and Categories
Acute Tox. 4 (93.5%)
Acute Tox. 4 (57.7%)
Sicherheit und Schutzausrüstung
Fire Fighting Procedures
Water spray, dry chemical, carbon dioxide, or foam as appropriate for surrounding fire and materials.
As with all fires, evacuate personnel to a safe area. Firefighters should use self-contained breathing equipment and protective clothing.
Disposal Methods
SRP: Expired or waste pharmaceuticals shall carefully take into consideration applicable DEA, EPA, and FDA regulations. It is not appropriate to dispose by flushing the pharmaceutical down the toilet or discarding to trash. If possible return the pharmaceutical to the manufacturer for proper disposal being careful to properly label and securely package the material. Alternatively, the waste pharmaceutical shall be labeled, securely packaged and transported by a state licensed medical waste contractor to dispose by burial in a licensed hazardous or toxic waste landfill or incinerator.
SRP: At the time of review, regulatory criteria for small quantity disposal are subject to significant revision, however, household quantities of waste pharmaceuticals may be managed as follows: Mix with wet cat litter or coffee grounds, double bag in plastic, discard in trash.
Preventive Measures
Engineering controls such as exhaust ventilation are recommended.
SRP: Local exhaust ventilation should be applied wherever there is an incidence of point source emissions or dispersion of regulated contaminants in the work area. Ventilation control of the contaminant as close to its point of generation is both the most economical and safest method to minimize personnel exposure to airborne contaminants. Ensure that the local ventilation moves the contaminant away from the worker.
This material is assumed to be combustible. As with all dry powders, it is advisable to ground mechanical equipment in contact with dry material to dissipate the potential buildup of static electricity.
As a general rule, when handling USP Reference Standards, avoid all contact and inhalation of dust, mists, and/or vapors associated with the material. Wash thoroughly after handling.
Personal Protective Equipment (PPE)
Use a NIOSH-approved respirator, if it is determined to be necessary by an industrial hygiene survey involving air monitoring. In the event that a respirator is not required, an approved dust mask should be used.
Wear approved respiratory protection, chemically compatible gloves, and protective clothing.
Toxikologische Informationen
Treatment
If the compound has been ingested, rapid gastric lavage should be performed using 5% sodium bicarbonate. For skin contact, the skin should be washed with soap and water. If the compound has entered the eyes, they should be washed with large quantities of isotonic saline or water. In serious cases, atropine and/or pralidoxime should be administered. Anti-cholinergic drugs work to counteract the effects of excess acetylcholine and reactivate AChE. Atropine can be used as an antidote in conjunction with pralidoxime or other pyridinium oximes (such as trimedoxime or obidoxime), though the use of '-oximes' has been found to be of no benefit, or possibly harmful, in at least two meta-analyses. Atropine is a muscarinic antagonist, and thus blocks the action of acetylcholine peripherally.
Health Effects
Acute exposure to cholinesterase inhibitors can cause a cholinergic crisis characterized by severe nausea/vomiting, salivation, sweating, bradycardia, hypotension, collapse, and convulsions. Increasing muscle weakness is a possibility and may result in death if respiratory muscles are involved. Accumulation of ACh at motor nerves causes overstimulation of nicotinic expression at the neuromuscular junction. When this occurs symptoms such as muscle weakness, fatigue, muscle cramps, fasciculation, and paralysis can be seen. When there is an accumulation of ACh at autonomic ganglia this causes overstimulation of nicotinic expression in the sympathetic system. Symptoms associated with this are hypertension, and hypoglycemia. Overstimulation of nicotinic acetylcholine receptors in the central nervous system, due to accumulation of ACh, results in anxiety, headache, convulsions, ataxia, depression of respiration and circulation, tremor, general weakness, and potentially coma. When there is expression of muscarinic overstimulation due to excess acetylcholine at muscarinic acetylcholine receptors symptoms of visual disturbances, tightness in chest, wheezing due to bronchoconstriction, increased bronchial secretions, increased salivation, lacrimation, sweating, peristalsis, and urination can occur. Certain reproductive effects in fertility, growth, and development for males and females have been linked specifically to organophosphate pesticide exposure. Most of the research on reproductive effects has been conducted on farmers working with pesticides and insecticdes in rural areas. In females menstrual cycle disturbances, longer pregnancies, spontaneous abortions, stillbirths, and some developmental effects in offspring have been linked to organophosphate pesticide exposure. Prenatal exposure has been linked to impaired fetal growth and development. Neurotoxic effects have also been linked to poisoning with OP pesticides causing four neurotoxic effects in humans: cholinergic syndrome, intermediate syndrome, organophosphate-induced delayed polyneuropathy (OPIDP), and chronic organophosphate-induced neuropsychiatric disorder (COPIND). These syndromes result after acute and chronic exposure to OP pesticides.
Adverse Effects
ALA is considered a safe supplementation without any adverse effects. One study supports the safety of the drug, and an adult can take up to 2400 mg without experiencing any harmful adverse effects. High doses of ALA are not recommended as higher doses provide no additional benefits. The most common adverse effects reported with ALA are headache, heartburn, nausea, and vomiting.
Toxicity Summary
ALA is generally considered a safe drug. A daily dose of 200 mg/day to 2400 mg/day of ALA is deemed safe without significant adverse effects. However, there is no reported safe dose in children.
(R)-lipoic acid is a cholinesterase or acetylcholinesterase (AChE) inhibitor. A cholinesterase inhibitor (or 'anticholinesterase') suppresses the action of acetylcholinesterase. Because of its essential function, chemicals that interfere with the action of acetylcholinesterase are potent neurotoxins, causing excessive salivation and eye-watering in low doses, followed by muscle spasms and ultimately death. Nerve gases and many substances used in insecticides have been shown to act by binding a serine in the active site of acetylcholine esterase, inhibiting the enzyme completely. Acetylcholine esterase breaks down the neurotransmitter acetylcholine, which is released at nerve and muscle junctions, in order to allow the muscle or organ to relax. The result of acetylcholine esterase inhibition is that acetylcholine builds up and continues to act so that any nerve impulses are continually transmitted and muscle contractions do not stop. Among the most common acetylcholinesterase inhibitors are phosphorus-based compounds, which are designed to bind to the active site of the enzyme. The structural requirements are a phosphorus atom bearing two lipophilic groups, a leaving group (such as a halide or thiocyanate), and a terminal oxygen.
Signs and Symptoms
Symptoms of low dose exposure include excessive salivation and eye-watering. Acute dose symptoms include severe nausea/vomiting, salivation, sweating, bradycardia, hypotension, collapse, and convulsions. Increasing muscle weakness is a possibility and may result in death if respiratory muscles are involved. Hypertension, hypoglycemia, anxiety, headache, tremor and ataxia may also result.
Natural Pollution Sources
Growth factor for many bacteria and protozoa; prosthetic group, coenzyme, or substrate in plants, microorganisms, and animal tissues ... The dl-form is naturally occurring. /Thioctic acid/
alpha-Lipoic acid is found in plants such as spinach and broccoli(1).
alpha-Lipoic acid is a naturally occurring compound that is synthesized in small amounts by plants and animals. Animal tissues shown to contain this compound are the kidney, heart, and liver(1).
Human Toxicity Excerpts
/CASE REPORTS/ Insulin Autoimmune Syndrome (IAS) is a rare disease characterized by hypoglycemia and autoantibodies to insulin without prior insulin administration. Here, we report a case of IAS associated with alpha lipoic acid. The patient is a 55-year-old man. He began to complain of hypoglycemic symptoms after taking alpha lipoic acid. He lost consciousness in the late postprandial period and blood glucose was found to be 27 mg/dl. A high insulin level and high titers of insulin antibodies were detected. His HLA genotype contains DRB1* 0406.
Non-Human Toxicity Excerpts
/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ Alpha-lipoic acid, also referred to as thioctic acid, has been demonstrated to exhibit strong anti-oxidant properties. In order to test the long-term toxicity of alpha-lipoic acid, groups of 40-50 male and female, 5-6-week-old, Sprague-Dawley rats were subjected to oral administration of 20, 60, or 180 mg/kg body weight (bw)/day alpha for 24 months. There was no significant difference between control animals and treated animals at 20 or 60 mg/kg bw/day with respect to body weight gain, food consumption, behavioral effects, hematological and clinical chemistry parameters, and gross and histopathological findings. In all treatment groups, mortality was slightly lower as compared to the control. The absolute weights of the heart (high-dose males), thymus (high-dose males), and left adrenal (mid-dose males), liver (high-dose females), and lungs (high-dose females) were decreased in comparison to controls. These changes were of no toxicological significance. The only notable finding in rats of both sexes dosed at 180 mg/kg bw/day was a reduction in food intake relative to the controls and a concomitant decrease in body weight. This decrease in body weight led to significant differences between the control and high-dose rats with respect to the absolute weights of certain organs. However, no gross or histopathological changes were associated with these findings. The no-observed-adverse-effect level (NOAEL) is considered to be 60 mg/kg bw/day.
/VETERINARY CASE REPORTS/ Suspected alpha lipoic acid (ALA) toxicity was diagnosed based on clinical history and compatible laboratory findings in 2 dogs. Case 1 was presented within 10 hours of ALA ingestion, with initial behavioral changes likely due to hypoglycemia. During the course of hospitalization, hypoglycemia persisted and evidence of acute hepatic insult developed. With aggressive supportive care (including IV fluids with dextrose supplementation, hepatoprotective medications, and a plasma transfusion), he made a full recovery. Case 2 was presented approximately 60 hours after ALA ingestion, and was found to be in oliguric renal failure. She was treated with IV fluids, gastroprotective medications, and furosemide, but her condition deteriorated and she was ultimately euthanized within 16 hours of admission to the hospital.
Antidote and Emergency Treatment
/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on the left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Poisons A and B/
/SRP:/ Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Cover skin burns with dry sterile dressings after decontamination ... . /Poisons A and B/
/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poisons A and B/
Sicherheitsdaten
- wgk
- 3
- hs_code
- 29349990
- RTECS-Nr.
- JP1192000
- risk_code
- 22-20/21/22
- hazard_code
- Xn
- safety_code
- 37/39-26-24/25-36-36/37/39
- Speicherklasse
- 11 - Combustible Solids
- Giftige Stoffe Daten
- 1077-28-7(Hazardous Substances Data)
- Hazard Classifications
- Acute Tox. 4 OralAquatic Chronic 2Eye Irrit. 2Skin Irrit. 2Skin Sens. 1
Chemie und Industrie
Pharmakologische Informationen
ATC Code
A - Alimentary tract and metabolism
QA - Alimentary tract and metabolism
Mechanism of Action
Alpha-lipoic acid (LA) shows a protective effect on oxidative stress-induced apoptosis while it induces apoptosis in various cancer cells. Intracellular Ca(2+) plays a central role in triggering apoptotic pathways. In the present study, we aim to investigate whether LA induces apoptosis in lung cancer cells and whether Ca(2+) is involved in LA-induced apoptosis. We found that LA decreased cell viability and increased DNA fragmentation of the cells. LA activated the caspase-independent pathway, determined by upregulation of poly(ADP-ribose) polymerase (PARP) and increased the nuclear level of apoptosis-inducing factor and caspase-dependent apoptotic pathway, determined by increased levels of cytochrome c and PARP-1 cleavage product. LA-induced apoptotic alterations were inhibited in the cells treated with Ca(2+) chelator BAPTA-AM. In conclusion, LA induces apoptosis through caspase-independent and caspase-dependent pathways, which is mediated by intracellular Ca(2+).
Alpha-lipoic acid is known to increase insulin sensitivity in vivo and to stimulate glucose uptake into adipose and muscle cells in vitro. In this study, alpha-lipoic acid was demonstrated to stimulate the autophosphorylation of insulin receptor and glucose uptake into 3T3-L1 adipocytes by reducing the thiol reactivity of intracellular proteins. To elucidate mechanism of this effect, role of protein thiol groups and H(2)O(2) in insulin receptor autophosphorylation and glucose uptake was investigated in 3T3-L1 adipocytes following stimulation with alpha-lipoic acid. Alpha-lipoic acid or insulin treatment of adipocytes increased intracellular level of oxidants, decreased thiol reactivity of the insulin receptor beta-subunit, increased tyrosine phosphorylation of the insulin receptor, and enhanced glucose uptake. Alpha-lipoic acid or insulin-stimulated glucose uptake was inhibited (i) by alkylation of intracellular, but not extracellular, thiol groups downstream of insulin receptor activation, and (ii) by diphenylene iodonium at the level of the insulin receptor autophosphorylation. alpha-Lipoic acid also inhibited protein tyrosine phosphatase activity and decreased thiol reactivity of protein tyrosine phosphatase 1B. These findings indicate that oxidants produced by alpha-lipoic acid or insulin are involved in activation of insulin receptor and in inactivation of protein tyrosine phosphatases, which eventually result in elevated glucose uptake into 3T3-L1 adipocytes.
Reactive oxygen (ROS) and nitrogen oxide (RNOS) species are produced as by-products of oxidative metabolism. A major function for ROS and RNOS is immunological host defense. Recent evidence indicate that ROS and RNOS may also function as signaling molecules. However, high levels of ROS and RNOS have been considered to potentially damage cellular macromolecules and have been implicated in the pathogenesis and progression of various chronic diseases. alpha-Lipoic acid and dihydrolipoic acid exhibit direct free radical scavenging properties and as a redox couple, with a low redox potential of -0.32 V, is a strong reductant. Several studies provided evidence that alpha-lipoic acid supplementation decreases oxidative stress and restores reduced levels of other antioxidants in vivo. However, there is also evidence indicating that alpha-lipoic acid and dihydrolipoic acid may exert prooxidant properties in vitro. alpha-Lipoic acid and dihydrolipoic acid were shown to promote the mitochondrial permeability transition in permeabilized hepatocytes and isolated rat liver mitochondria. Dihydrolipoic acid also stimulated superoxide anion production in rat liver mitochondria and submitochondrial particles. alpha-Lipoic acid was recently shown to stimulate glucose uptake into 3T3-L1 adipocytes by increasing intracellular oxidant levels and/or facilitating insulin receptor autophosphorylation presumably by oxidation of critical thiol groups present in the insulin receptor beta-subunit. Whether alpha-lipoic acid and/or dihydrolipoic acid-induced oxidative protein modifications contribute to their versatile effects observed in vivo warrants further investigation.
This study investigated the effect of alpha-lipoic acid (ALA) in concentration range 0.7-5.0 mM on the intracellular level of reduced glutathione, the cell cycle phase distribution, the structure of microfilaments and microtubules of normal (3T3) and transformed (3T3-SV40) fibroblasts. We obtained that ALA increased the glutathione content in transformed cells, but did not change its level in normal cells, induced cell cycle arrest of 3T3 cells (but not 3T3-SV40 cells), and disrupted actin microfilaments in cells of both lines. The effect of ALA was compared with N-acetylcysteine (NAC) action. The whole complex of findings allows us to affirm that each of these antioxidants acts on its own target molecules in normal and transformed cells and activates different signal and metabolic pathways in these cells. But at the same time the intermediate steps of ALA and NAC action can be common (alteration of the intracellular level of glutathione, reorganization of actin cytoskeleton, etc.).
For more Mechanism of Action (Complete) data for alpha-Lipoic acid (7 total), please visit the HSDB record page.
Metabolism/Metabolites
Alpha-lipoic acid is metabolized to its reduced form, dihydrolipoic acid by mitochondrial lipoamide dehydrogenase. Dihydroipoic acid, together with lipoic acid, form a redox couple. It is also metabolized to lipoamide, which functions as the lipoic acid cofactor in the multienzyme complexes that catalyze the oxidative decarboxylations of pyruvate and alpha-ketoglutarate. Alpha-lipoic acid may be metabolized to dithiol octanoic acid, which can undergo catabolism.
The excretion and biotransformation of rac-alpha-lipoic acid (LA), which is used for the symptomatic treatment of diabetic polyneuropathy, were investigated following single oral dosing of [(14)C]LA to mice (30 mg/kg), rats (30 mg/kg), dogs (10 mg/kg), and unlabeled LA to humans (600 mg). More than 80% of the radioactivity given was renally excreted. Metabolite profiles obtained by radiometric high-performance liquid chromatography revealed that LA was extensively metabolized irrespective of the species. Based on a new on-line liquid chromatography/tandem mass spectroscopy assay developed for negative ions, LA and a total of 12 metabolites were identified. Mitochondrial beta-oxidation played the paramount role in the metabolism of LA. Simultaneously, the circulating metabolites were subjected to reduction of the 1,2-dithiolane ring and subsequent S-methylation. In addition, evidence is given for the first time that the methyl sulfides formed were partly oxidized to give sulfoxides, predominantly in dogs. The disulfoxide of 2,4-bismethylmercapto-butanoic acid, the most polar metabolite identified, was the major metabolite in dogs. Furthermore, new data are presented that suggest conjugation with glycine occurred as a separate metabolic pathway in competition with beta-oxidation, predominantly in mice.
Paraoxonase (PON1) is a key enzyme in the metabolism of organophosphates. PON1 can inactivate some organophosphates through hydrolysis. PON1 hydrolyzes the active metabolites in several organophosphates insecticides as well as, nerve agents such as soman, sarin, and VX. The presence of PON1 polymorphisms causes there to be different enzyme levels and catalytic efficiency of this esterase, which in turn suggests that different individuals may be more susceptible to the toxic effect of OP exposure.
MeSH Pharmacological Classification
Naturally occurring or synthetic substances that inhibit or retard oxidation reactions. They counteract the damaging effects of oxidation in animal tissues.
A group of water-soluble vitamins, some of which are COENZYMES.
Absorption, Distribution and Excretion
To determine the concentration of alpha-lipoic acid in the aqueous humour and investigate if its topical instillation can increase quantities. Methods: Seventy patients selected to undergo cataract surgery were randomly divided into two groups. Group 1 was used as a control group; for the patients in Group 2, a single instillation of alpha-lipoic acid eye drops (1%) was administered. Immediately before surgery an aliquot of 40-120 microL of aqueous humour was aspirated. The individual aspirations were combined to constitute pools representing time intervals with respect to administration. The levels of alpha-lipoic acid in the aqueous humour were measured using gas chromatography/mass-spectrometry. Pool 0 was created by combining the samples of aqueous humour obtained from the patients in Group 1, the control group, and the level of alpha-lipoic acid was 27.5 + 2.6 ng/mL; in the other pools the time interval between the administration of the eye drops and sampling was respectively 23 minutes, 53 minutes, 72 minutes, 93 minutes and 114 minutes, and the level of alpha-lipoic acid was 33.0 + 10.8 ng/mL; 52.0 + 2.5 ng/mL; 86.7 + 2.5 ng/mL; 91.2 + 2.5 ng/mL; 80.3 + 2.5 ng/mL. /The/ study demonstrates the presence of alpha-lipoic acid in the aqueous humour and indicates that its concentration increases after it is administered in the form of eye drops, reaching maximum values after around 93 minutes. The concentrations that are achieved in the anterior chamber allow us to theorise the possibility of exploiting the antioxidant properties of alpha-lipoic acid.
R(+)-alpha-lipoic acid is a natural occurring compound that acts as an essential cofactor for certain dehydrogenase complexes. The redox couple alpha-lipoic acid/dihydrolipoic acid possesses potent antioxidant activity. Exogenous racemic alpha-lipoic acid orally administered for the symptomatic treatment of diabetic polyneuropathy is readily and nearly completely absorbed, with a limited absolute bioavailability of about 30% caused by high hepatic extraction. Although the pharmacokinetics of the parent drug have been well characterized in humans, relatively little is known regarding the excretion of alpha-lipoic acid and the pharmacokinetics of any metabolites in humans. In the present study, plasma concentration-time courses, urinary excreted amounts, and pharmacokinetic parameters of alpha-lipoic acid metabolites were evaluated in 9 healthy volunteers after multiple once-daily oral administration of 600 mg racemic alpha-lipoic acid. The primary metabolic pathways of alpha-lipoic acid in man, S-methylation and beta-oxidation, were quantitatively confirmed by an HPLC-electrochemical assay newly established prior to the beginning of this study. Major circulating metabolites were the S-methylated beta-oxidation products 4,6-bismethylthio-hexanoic acid and 2,4-bismethylthio-butanoic acid, whereas its conjugated forms accounted for the major portion excreted in urine. There was no statistically significant difference in the pharmacokinetic parameters Cmax, AUC, and tmax between day 1 and day 4. Despite the prolonged half-lives of the major metabolites compared to the parent drug, no evidence of accumulation was found. Mean values of 12.4% of the administered dose were recovered in the urine after 24 hours as the sum of alpha-lipoic acid and its metabolites. The results of the present study revealed that urinary excretion of alpha-lipoic acid and five of its main metabolites does not play a significant role in the elimination of alpha-lipoic acid. Therefore, biliary excretion, further electrochemically inactive degradation products, and complete utilization of alpha-lipoic acid as a primary substrate in the endogenous metabolism should be considered.
In an open-label, parallel-group study involving 16 patients (8 with severely reduced renal function, 8 with end-stage renal disease needing hemodialysis), the effect of renal function on the pharmacokinetics, metabolism, and safety `of alpha-lipoic acid (thioctic acid) was evaluated by comparing the pharmacokinetic parameters with those of a reference group of 8 healthy subjects. Alpha-lipoic acid 600 mg was administered orally once daily for 4 days, and the pharmacokinetic parameters were measured on days 1 and 4. The mean percentage of the administered dose excreted in urine as parent compound was 0.2 and 0.05 in healthy subjects and subjects with severely reduced renal function, respectively. Assuming a bioavailability of 30%, this represents 0.67% and 0.17% of the bioavailable amount of alpha-lipoic acid, respectively. The percentage of total urinary recovered amounts of alpha-lipoic acid and 5 of its metabolites was 12.0 on both days. The respective values for patients with severe kidney damage were 5.2% (day 1) and 6.4% (day 4). The total percentage of the administered dose removed by hemodialysis was 4.0 in patients with end-stage renal disease. Renal clearance of alpha-lipoic acid and its major metabolites, 6,8-bismethylthio-octanoic acid, 4,6-bismethylthio-hexanoic acid and 2,4-bismethylthio-butanoic acid, were significantly decreased in subjects with kidney damage compared to the reference group. Apparent total clearance of alpha-lipoic acid was poorly correlated with creatinine clearance. There is strong evidence that alpha-lipoic acid is mainly excreted by nonrenal mechanism or further degraded to smaller units in the catabolic process. The significantly increased area under the curve values of 4,6-bismethylthio-hexanoic acid and half-lives of 2,4-bismethylthio-butanoic acid on both days in patients with severely reduced function and end-stage renal disease were not considered to be clinically relevant. Although trough levels of both metabolites tend to increase slightly in these subjects, no accumulation effects were detected. We conclude that the pharmacokinetics of alpha-lipoic acid are not influenced by creatinine clearance and are unaffected in subjects with severely reduced kidney function or end-stage renal disease. Hemodialysis did not significantly contribute to the clearance of alpha-lipoic acid. Hence, dose adjustment of alpha-lipoic acid is not necessary in patients with renal dysfunction.
Alpha-lipoic aicd is absorbed from the small intestine and distributed to the liver via the portal circulation and to various tissues in the body via the systemic circulation.The natural R-enantiomer is more readily absorbed than the L-enantiomer and is the more active form. Alpha-lipoic acid readily crosses the blood-brain barrier. It is found, after its distribution to the various body tissues, intracellularly, intramitochondrialy and extracellularly.
Verwendung und Herstellung
Uses
Nutrition, biochemical research /Thioctic acid, dl-form/
THERAPEUTIC CATEGORY: Treatment of liver disease; antidote to poisonous mushrooms (Amanita species).
Use (kg; approx.) in Germany (2009): >7500
For nutritional supplementation, also for treating dietary shortage or imbalance.
Methods of Manufacturing
Industrial synthesis of thioctic acid is performed in three stages. Monomethyl or monoethyl adipate is converted into the corresponding acid chloride by reaction with thionyl chloride. Treatment with ethylene in the presence of anhydrous aluminum chloride yields 8-chloro-6-ketooctanoate. In the second stage, this ester is reduced to 8-chloro-6-hydroxyoctanoate by using thionyl chloride in pyridine. In the third stage, the chlorine atoms are replaced by sulfur atoms by treatment with sodium disulfide. Hydrolysis of the resulting dithionooctyl ester formed with alcoholic potassium hydroxide gives thioctic acid.
Formulations/Preparations
Oral: Capsules 30 mg Coenzyme Q10, 12-5 mg alpha-Lipoic Acid, Coquinone 30 (USANA Health Sciences Inc). /Coquinone 30/
Juvenon: acetyl-L-carnitine and alpha lipoic acid
Anwendungen
BeschreibungDL-α-Lipoic acid is a cyclic disulfide antioxidant that interconverts with its reduced dithiol form. It is an essential cofactor for decarboxylation reactions of the citric acid cycle, and acts as a general antioxidant. DL-α-lipoic acid can act as a direct radical scavenger, as a cofactor to regenerate reduced glutathione, and as a metal chelator.
Verwenden(±)-α-Lipoic acid has been used in in vitro lipoylation studies and in the pyruvate dehydrogenase complex (PDC)-pyruvate dehydrogenase kinase (PDHK) functional assay. It has also been used to investigate its antioxidative effect on developing cerebellum of rats exposed to arsenic during postnatal period.
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