Ketone Ester (R-BHB)
| Product Name | Ketone Ester (R-BHB) |
|---|---|
| CAS Number | 1208313-97-6 |
| Other Names | (R)-3-Hydroxybutyl (R)-3-hydroxybutyrate; (R)-3-Hydroxybutyrate (R)-3-hydroxybutyl ester; (R)-3-HB (R)-3-HB |
| Molecular Formula | C8H16O4 |
| Molecular Weight | 176.21 g/mol |
| Appearance | Colorless to pale yellow, clear liquid |
| Assay (HPLC) | ≥ 98.0% |
| Optical Purity | ≥ 99.0% ee |
| Water Content (Karl Fischer) | ≤ 0.5% |
| Heavy Metals | ≤ 10 ppm |
| Solubility | Soluble in water, ethanol, propylene glycol; miscible with many organic solvents |
| Package | 25 kg HDPE drum, 200 kg stainless steel drum |
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Synonyms: (R)-3-Hydroxybutyl (R)-3-hydroxybutyrate, (R)-3-HB (R)-3-HB, Ketone Ester, R-BHB, (R)-3-Hydroxybutyrate (R)-3-hydroxybutyl ester, C8H16O4
Ketone Ester (R-BHB) is a chiral ester formed from two molecules of (R)-3-hydroxybutyric acid, linked through an ester bond between the carboxyl group of one unit and the hydroxyl group of the other. This symmetrical diester is chemically stable yet readily hydrolyzed by endogenous esterases, releasing free (R)-3-hydroxybutyrate (R-BHB) — the primary ketone body that circulates during nutritional ketosis. The (R) configuration is critical for biological activity; the (S) enantiomer is not efficiently utilized by the body and may even interfere with ketone metabolism. Thus, the compound is produced with high optical purity to ensure maximal bioavailability and metabolic effect.
Unlike salts such as sodium or magnesium BHB, ketone ester is not bound to a mineral carrier. This makes it particularly attractive for formulations where high mineral loads are undesirable — for instance, in sports nutrition or clinical nutrition for patients on sodium-restricted diets. The ester is typically supplied as a clear, slightly viscous liquid with a mild, characteristic odor. It is miscible with water and common solvents, which facilitates incorporation into beverages, gels, and liquid concentrates. The material is produced via a multi-step synthetic route that includes chiral resolution or asymmetric synthesis to achieve the desired (R,R) stereochemistry.
In the research and supplement space, Ketone Ester (R-BHB) has gained attention as a tool to induce rapid and sustained elevations in blood ketone levels without the need for fasting or strict carbohydrate restriction. This has made it a valuable ingredient in studies exploring ketosis as a metabolic therapy, as well as in performance nutrition products aimed at endurance athletes and military personnel. Its ability to deliver ketones efficiently while avoiding the gastrointestinal discomfort sometimes associated with salt-based ketone supplements has driven demand in both clinical and sports nutrition segments.
Ketone Ester (R-BHB) is a low-molecular-weight diester with the formula C8H16O4 and a molecular weight of 176.21 g/mol. The molecule consists of two (R)-3-hydroxybutyrate units joined by an ester linkage, resulting in a neutral, lipophilic compound that is more palatable and better tolerated than free acids or salts. It is a clear liquid at room temperature, with a density of approximately 1.1 g/cm³ and a refractive index around 1.44. The ester is hydrolyzed in vivo by carboxylesterases, primarily in the liver and intestine, to yield two molecules of (R)-3-hydroxybutyrate, which then enter the bloodstream and are taken up by tissues for energy metabolism. The compound is stable under recommended storage conditions (cool, dry, away from light) but should be protected from excessive heat and moisture to prevent hydrolysis.
| Parameter | Specification |
|---|---|
| Assay (HPLC) | ≥ 98.0% |
| Optical Purity | ≥ 99.0% ee (R,R) |
| Appearance | Colorless to pale yellow liquid |
| Water Content | ≤ 0.5% |
| Heavy Metals | ≤ 10 ppm |
| Residual Solvents | Meets ICH Q3C limits |
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