3,8-Dihydroxy-6H-dibenzo[b,d]pyran-6-one
[CAS# 1143-70-0]

Identification

• Classification: Pharmaceutical intermediate >> Heterocyclic compound intermediate >> Pyran compound
• Name: 3,8-Dihydroxy-6H-dibenzo[b,d]pyran-6-one
• Synonyms: 2',7-Dihydroxy-3,4-benzocoumarin; 3,8-Dihydroxyurolithin; 3,8-Hydroxydibenzo-alpha-pyrone; Urolithin A
• Molecular Formula: C₁₃H₈O₄
• Molecular Weight: 228.20
• CAS Registry Number: 1143-70-0
• EC Number: 881-478-5
• SMILES: C1=CC2=C(C=C1O)C(=O)OC3=C2C=CC(=C3)O

Properties

• Solubility: Very slightly soluble (0.18 g/L) (25 °C), Calc.^*
• Density: 1.516±0.06 g/cm³ (20 °C 760 Torr), Calc.^*
• Melting point: 340-345 °C^**
• Index of Refraction: 1.718, Calc.^*
• Boiling Point: 527.9±43.0 °C (760 mmHg), Calc.^*
• Flash Point: 214.2±21.7 °C, Calc.^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software V11.02 (©1994-2016 ACD/Labs)

^** Pope, G. S.

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H319
• Safety Statements: P264-P264+P265-P280-P302+P352-P305+P351+P338-P321-P332+P317-P337+P317-P362+P364

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319

Discovery and Applications

3,8-Dihydroxy-6H-dibenzo[b,d]pyran-6-one, commonly referred to as emodin, is a naturally occurring anthraquinone derivative found in various plant species, including rhubarb, buckthorn, and senna. Its distinctive structure, consisting of a fused dibenzo[b,d]pyranone ring system with hydroxyl groups at the 3- and 8-positions, contributes to its diverse biological activities and makes it a significant compound in both natural product chemistry and medicinal research.

The history of emodin traces back to traditional medicine, where plants containing this compound were employed for their laxative and anti-inflammatory properties. Early chemical investigations in the 19th century isolated emodin from rhubarb root, and subsequent studies elucidated its structure through advances in spectroscopy and crystallography. Its name derives from *Rheum emodi*, a plant species recognized as a primary source of this compound.

Emodin exhibits a range of pharmacological effects due to its ability to interact with multiple biological pathways. It is best known for its laxative properties, attributed to its influence on gastrointestinal motility. Additionally, emodin has demonstrated potential as an anti-inflammatory, antimicrobial, and anticancer agent. Studies suggest that it exerts these effects by modulating enzymes, signaling proteins, and transcription factors, such as nuclear factor kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs).

In modern applications, emodin has attracted interest for its role in cancer therapy research. Preclinical studies have indicated its ability to inhibit tumor cell proliferation, induce apoptosis, and suppress metastasis in various cancer models, including colorectal, breast, and lung cancers. These effects are linked to its interaction with pathways regulating cell cycle and oxidative stress. Furthermore, emodin's potential antiviral activity has been explored, particularly against coronaviruses and herpes simplex virus, providing avenues for therapeutic development.

Beyond medicine, emodin has been investigated for its use as a natural dye due to its vibrant coloration and chemical stability. In the food and cosmetics industries, it is used as a natural additive, although its safety and dosage must be carefully regulated due to its potent biological activity.

While the therapeutic potential of 3,8-Dihydroxy-6H-dibenzo[b,d]pyran-6-one is promising, challenges remain regarding its bioavailability, solubility, and toxicity at high doses. Ongoing research focuses on developing derivatives and formulations to enhance its efficacy and safety profile for clinical applications.

References

2024. Development of metabolic signatures of plant-rich dietary patterns using plant-derived metabolites. European Journal of Nutrition.
DOI: 10.1007/s00394-024-03511-x

2024. Activation of the Gut-Brain Interaction by Urolithin A and Its Molecular Basis. Nutrients.
DOI: 10.3390/nu16193369

2024. Urolithin A promotes the degradation of TMSB10 to deformation F-actin in non-small-cell lung cancer. Phytomedicine: international journal of phytotherapy and phytopharmacology.
DOI: 10.1016/j.phymed.2024.156109