(R)-Lipoic acid

Yellow Crystalline Solid

A fat-metabolism stimulator

α-Lipoic acid has been used as a reference standard for the analysis of α-lipoic acid in human plasma by high performance liquid chromatography coupled to electron capture detector (HPLC-ECD), in various food matrices and dietary supplements by HPLC combined with coulometric electrode array detector (CEAD) as well as electrospray ionization mass spectrometer (ESI-MS).
It may be used as a reference standard for the determination of α-lipoic acid in human urine by isocratic reversed-phase HPLC and in α-lipoic acid capsules by HPLC with chemiluminescence detection.

ChEBI: (R)-lipoic acid is the (R)-enantiomer of lipoic acid. A vitamin-like, C8 thia fatty acid with anti-oxidant properties. It has a role as a prosthetic group, a nutraceutical and a cofactor. It is a lipoic acid, 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 (R)-lipoate. It is an enantiomer of a (S)-lipoic acid.

α-Lipoic acid is an antioxidant which is generally present in plants, animals and many other microorganisms.

(R)-(+)-α-Lipoic acid was shown to significantly increase pyruvate oxidation while abrogating fatty acid oxidation in rat hepatocytes. These effects make R-(+)-α-Lipoic acid a promising treatment option for the treatment of Type II diabetes. It is a biological antioxidant with prooxidant activities, its therapeutic potential is widely investigated, e.g. in the treatment for Alzheimer′s disease.

(R)-Lipoic acid can be prepared via a six-step enantioselective synthesis from 6-bromohex-1-ene, where stereocontrol is achieved through Sharpless asymmetric epoxidation of an intermediate allyl alcohol[2]. Alternatively, the compound is synthesized in six steps using a monooxygenase-catalyzed biotransformation as the key step[1].

[1] Adger, B., Bes, M., Grogan, G., McCague, R., Pedragosa-Moreau, S., Roberts, S. M., Villa, R., Wan, P. W., & Willets, A. J. (1997). The synthesis of (R)-(+)-lipoic acid using a monooxygenase-catalysed biotransformation as the key step. Bioorganic & Medicinal Chemistry, 5(2), 253–261. https://doi.org/10.1016/s0968-0896(96)00234-9
[2] Page, P. C. B., Rayner, C. M., & Sutherland, I. O. (1990). An enantioselective synthesis of R-(+)-α-lipoic acid. J. Chem. Soc., Perkin Trans. 1, 1615–1618. https://doi.org/10.1039/p19900001615