Pharmacological Activities, Biosynthetic Strategies, and Future Prospects: A Comprehensive Review of Baicalein

Abstract Baicalein, a 4′-deoxyflavone from Scutellaria baicalensis Georgi, possesses diverse pharmacological activities including antimicrobial, antifibrotic, antiviral, antitumor, and antioxidant effects. Its effective antioxidant and anti-inflammatory properties position it as a promising functional food ingredient and nutraceutical candidate. Traditional production via plant extraction is limited by long growth cycles and low yields, while chemical synthesis uses toxic reagents and harsh conditions. Microbial biosynthesis offers a sustainable alternative. To date, baicalein titers of 367.8 mg/L in Escherichia coli and 401.9 mg/L in Pichia pastoris have been achieved through pathway optimization. However, a systematic review integrating its bioactivities and biosynthesis is still lacking. This review summarizes baicalein’s sources, structure, pharmacological activities, and applications, with a focus on heterologous biosynthesis and pathway optimization. Future prospects are also proposed to promote its further biomedical applications and efficient production.