Triterpenoids in food and medicine homology substances: Structural diversity, bioactivities, biosynthesis, and strategies for efficient production

Food and medicine homology (FMH) substances possess the dual capability of being used as both food and medicine. In recent years, the concept of FMH has been emphasized and developed in unprecedented ways. Triterpenoids, as key bioactive constituents within FMH substances, exhibit remarkable structural diversity and multi-target pharmacological activities, including anti-tumor, anti-inflammatory, antioxidant, hypoglycemic, and immunomodulatory effects. This review systematically summarizes the structural classification, spatiotemporal distribution patterns, and pharmacological mechanisms of FMH triterpenoids, with a particular focus on their dual role in disease prevention and functional foods. Addressing the challenge of low extraction efficiency from plants, synthetic biology approaches have elucidated the biosynthetic pathways regulated by rate-limiting enzymes, including oxidosqualene cyclases, cytochrome P450 monooxygenases, and UDP-glycosyltransferases. Synthetic biology strategies for the heterologous production of these triterpenoids in plant and microbial cell factories are critically evaluated. Despite advances in pathway reconstruction and enzyme engineering, challenges such as low yield, poor catalytic specificity, and scalability for industrial production persist. Emerging technologies, such as artificial intelligence-driven protein design and biosensor-based high-throughput screening, offer transformative solutions for optimizing triterpenoid biosynthesis. This work lays the groundwork for harnessing FMH triterpenoids as sustainable resources for pharmaceuticals and functional foods.