Urolithin B

Urolithin B is another gut microbial metabolite of ellagitannins, structurally similar to Urolithin A but with one fewer hydroxyl group (Urolithin B is 3-hydroxy-dibenzo-α-pyranone). It has drawn interest for its effects on skeletal muscle and metabolism. In vivo studies have identified Urolithin B as a positive regulator of muscle mass: it was shown to induce muscle fiber hypertrophy in mice and to mitigate muscle atrophy after neuroinjury. Urolithin B appears to act, at least in part, by enhancing protein synthesis pathways in muscle cells (e.g., activating mTOR signaling) and by downregulating the ubiquitin-proteasome pathway responsible for muscle protein breakdown. Interestingly, Urolithin B also has been noted to have an androgenic-like effect on muscle without affecting other androgen-sensitive organs, implying a degree of tissue selectivity. Beyond muscle, Urolithin B exhibits anti-inflammatory properties. It can inhibit NF-κB activation and reduce pro-inflammatory mediator production in macrophages, which contributes to an overall protective effect in metabolic tissues. While Urolithin B is less studied than Urolithin A in human contexts, these findings suggest it could be useful in preventing muscle wasting (sarcopenia) or as a sports nutrition supplement. Further clinical research is needed to establish safety, bioavailability, and efficacy in humans.

• CAS: 1139-83-9
• Molar Mass: 212.20 g/mol
• Chemical Formula: C_13H_8O_3
• Storage: Store at –20 °C, protected from light and moisture. Use desiccant to keep dry.
• Purity: ≥ 98.5% (NMR)
• Quantity: 2 g powder