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Equol (racemic), the racemic mixture of equol, is a medication that hinders the growth of human gastric cancer cells and may be used to treat acute thyroid disease. S-equol and R-equol are combined to form equol (racemic).
Physicochemical Properties
| Molecular Formula | C15H14O3 |
| Molecular Weight | 242.274 |
| Exact Mass | 242.094 |
| Elemental Analysis | C, 74.36; H, 5.82; O, 19.81 |
| CAS # | 94105-90-5 |
| Related CAS # | (-)-(S)-Equol;531-95-3;(R)-Equol;221054-79-1 |
| PubChem CID | 382975 |
| Appearance | White to yellow solid powder |
| Density | 1.3±0.1 g/cm3 |
| Boiling Point | 441.7±45.0 °C at 760 mmHg |
| Melting Point | 158-160ºC |
| Flash Point | 220.9±28.7 °C |
| Vapour Pressure | 0.0±1.1 mmHg at 25°C |
| Index of Refraction | 1.645 |
| LogP | 2.98 |
| Hydrogen Bond Donor Count | 2 |
| Hydrogen Bond Acceptor Count | 3 |
| Rotatable Bond Count | 1 |
| Heavy Atom Count | 18 |
| Complexity | 273 |
| Defined Atom Stereocenter Count | 0 |
| SMILES | OC1C=CC(C2CC3C(=CC(=CC=3)O)OC2)=CC=1 |
| InChi Key | ADFCQWZHKCXPAJ-UHFFFAOYSA-N |
| InChi Code | InChI=1S/C15H14O3/c16-13-4-1-10(2-5-13)12-7-11-3-6-14(17)8-15(11)18-9-12/h1-6,8,12,16-17H,7,9H2 |
| Chemical Name | 3-(4-hydroxyphenyl)-3,4-dihydro-2H-chromen-7-ol |
| Synonyms | (±)-Equol; (-)-(S)-Equol; (-)-Equol; (3S)-Equol; 3-(4-hydroxyphenyl)chroman-7-ol; Equol; (+/-)-Equol; (R,S)-Equol; 66036-38-2; 7,4'-Homoisoflavane; 4',7-Dihydroxyisoflavane; (S)-Equol; AUS 131; Equol; S-Equol; SE 5OH |
| HS Tariff Code | 2934.99.9001 |
| Storage |
Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month |
| Shipping Condition | Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs) |
Biological Activity
| Targets | ERβ |
| ln Vitro | Equol is subsequently discovered in the urine of goats, cows, hens, and sheep[1]. It is initially isolated and recognized from the urine of pregnant mares. Equol can exist as two different diastereoisomers because it has a chiral center, unlike the soy isoflavones genistein and daidzein. The sole byproduct of soy isoflavone synthesis in the human gut is s-equol, which is bioavailable in both enantiomers. While R-equol is comparatively inactive, S-equol exhibits a high affinity for estrogen receptor beta (Ki=0.73 nM)[2]. Equol may enhance rat osteoblast growth and differentiation by triggering the signaling pathway linked to ER-PKCα. Significant increases in alkaline phosphatase activity are also observed in all equol and 17β-estradiol (E2) groups. Additionally, equol dramatically raises osteocalcin levels[3]. |
| ln Vivo | Equol is a mild vasorelaxant and natriuretic in rats. Equol taken orally has about 8 times less potency than furosemide taken orally. Equol administration relaxes the contracted aorta in isolated aortic rings precontracted by phenylephrine administration (concentration for half-maximal activity: 58.9±16 μM)[4]. Equol has anticancer properties; in rats with mammary gland tumors, it inhibits the growth of tumors by inducing apoptosis. Moreover, equol protects the liver by lowering apoptosis and functioning as an antioxidant[5]. |
| Enzyme Assay | Phytoestrogens have been suggested as alternative treatment for postmenopausal osteoporosis. Equol, a metabolite of daidzein, has been shown to inhibit bone loss in ovariectomized mice and rats. However, whether or not equol influences the formation of bone has not yet been investigated. Therefore, we investigated the effect of equol on the proliferation and differentiation of rat primary osteoblasts and explored the involved mechanisms. Different equol concentrations significantly promoted the proliferation of osteoblasts after 48- and 72-h incubations. The alkaline phosphatase (ALP) activity also increased significantly in all of the equol and 17β-estradiol (E2) groups, except for the lowest (0.01 μM) equol group. Equol also significantly elevated the osteocalcin levels. The effects of equol on osteoblast proliferation, ALP activity, and osteocalcin levels were blocked by the estrogen receptor (ER) antagonist ICI182780. After a 24-h incubation, the expression of protein kinase C alpha (PKCα) in osteoblasts was significantly increased by equol. In conclusion, our study demonstrated that equol could promote the proliferation and differentiation of rat osteoblasts through activating the ER-PKCα-related signaling pathway, suggesting that equol could promote bone formation. These results suggest that equol could be a potential alternative agent for the management of postmenopausal osteoporosis.[3] |
| Cell Assay | For 24 or 48 hours, 0.01-1 μM equol, 0.01-1 μM E2, or 0.01-1 μM equol/E2 combined with 1 μM ICI182780 are applied to primary rat osteoblasts. Each well is then filled with 10 mL of a 5 mg/mL MTT solution. Before taking measurements in a microplate reader, 100 mL of DMSO is added to each well and thoroughly mixed after the plates are incubated at 37°C for four hours[3]. The supernatant is then discarded. |
| Animal Protocol |
Rats: Groups of 3–9 rats are given oral doses of equol or furosemide (16, 40, and 100 mg/kg) in a volume of 16 mL/kg 5% arabic syrup (vehicle only is given to rats in the control group). Samples of urine are taken for six hours. Flame photometry is used to determine the sodium and potassium contents of the urine[3]. Mouse: Eight weeks after a single dose of DMBA (100 mg/kg), rats are given equol, which has been dissolved in water and given orally at a dose of 5 and 25 mg/kg BW. Rats are separated into vehicle alone and DMBA alone groups as controls. In the second phase, equol is given orally to ICR mice every day at a dose of 5 and 25 mg/kg BW for 7 weeks, prior to a single weekly dose of DMBA (34 mg/kg). Animals are observed nonstop for a week following equol administration. The six mice in each of the control groups are the same as in the previous group. Mammary gland tumors and mouse livers are separated, blotted, weighed, frozen in liquid nitrogen, and kept at -70°C until analysis[5]. |
| ADME/Pharmacokinetics |
Metabolism / Metabolites Equol has known human metabolites that include (2S,3S,4S,5R)-3,4,5-trihydroxy-6-[[3-(4-hydroxyphenyl)-3,4-dihydro-2H-chromen-7-yl]oxy]oxane-2-carboxylic acid. Equol is a known human metabolite of Tetrahydrodaidzein. |
| References |
[1]. The identification of the weak oestrogen equol [7-hydroxy-3-(4'-hydroxyphenyl)chroman] in human urine. Biochem J. 1982 Feb 1;201(2):353-7. [2]. S-equol, a potent ligand for estrogen receptor beta, is the exclusive enantiomeric form of the soy isoflavone metabolite produced by human intestinal bacterial flora. Am J Clin Nutr. 2005 May;81(5):1072-9. human intestinal bacterial flora. [3]. Equol promotes rat osteoblast proliferation and differentiation through activating estrogen receptor. Genet Mol Res. 2014 Jul 4;13(3):5055-63. [4]. Renal and vascular actions of equol in the rat. J Hypertens. 1997 Nov;15(11):1303-8. [5]. Anticancer mechanism of equol in 7,12-dimethylbenz(a)anthracene-treated animals. Int J Oncol. 2011 Sep;39(3):747-54. [6]. Enhanced gastrointestinal motility with orally active ghrelin receptor agonists. J Pharmacol Exp Ther. 2009;329(3):1178-1186. |
| Additional Infomation |
3-(4-Hydroxyphenyl)chroman-7-ol is a member of hydroxyisoflavans. Equol has been used in trials studying the treatment of Breast Cancer. A non-steroidal ESTROGEN generated when soybean products are metabolized by certain bacteria in the intestines. |
Solubility Data
| Solubility (In Vitro) |
DMSO: ~48 mg/mL (~198.1 mM) Ethanol: ~48 mg/mL (~198.1 mM) |
| Solubility (In Vivo) |
Solubility in Formulation 1: ≥ 2.5 mg/mL (10.32 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. Solubility in Formulation 2: ≥ 2.5 mg/mL (10.32 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly. Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution. Solubility in Formulation 3: ≥ 2.5 mg/mL (10.32 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly. (Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 4.1276 mL | 20.6381 mL | 41.2763 mL | |
| 5 mM | 0.8255 mL | 4.1276 mL | 8.2553 mL | |
| 10 mM | 0.4128 mL | 2.0638 mL | 4.1276 mL |