Phillyrin has good biological activity, but it is insoluble in water, which restricts its use in various industries. In our work, we prepared phillyrin using a green and rapid method from Forsythia suspensa leaves, and its purity is greater than 93%. Then, phillyrin was made to interact with different kinds of cyclodextrins (CDs) as a way to improve the water solubility of phillyrin, and the interaction mechanism between CDs and phillyrin was speculated by various characterization methods. First, phase solubility experiments showed that the phase solubility curves of all three CD inclusion complexes were AL-shaped, indicating that all three inclusion complexes were prepared using phillyrin with CDs in a 1 : 1 stoichiometric ratio. And based on this result, three cyclodextrin inclusion compounds, phillyrin/HP-β-CD (complexation efficiency (CE): 82.58%, the loading efficiency (LE): 22.27%), phillyrin/DM-β-CD IC (CE: 89.31%, LE: 24.83%) and phillyrin/β-CD IC (CE: 68.59%, LE: 23.67%), were prepared. Then, phillyrin was successfully encapsulated as determined by various characterization analyses, after which the conformations of the inclusion complex interactions were analyzed by NMR and molecular docking. The result also indicated that the water solubility of the phillyrin/HP-β-CD, phillyrin/DM-β-CD IC and phillyrin/β-CD IC has significantly improved, which was 30.02, 41.91 and 14.56 times higher than that of pure phillyrin. And the inclusion of CDs also considerably improved the antioxidant capacity of phillyrin, and the DPPH clearance rates of the three inclusion compounds were 4.34, 4.46 and 4.79 times higher than those of pure phillyrin, respectively, and the ABTS clearance rates were 1.35, 1.70 and 1.62 times higher than that of pure phillyrin. The prepared inclusion complexes can be applied in the functional food industry as active ingredients.
Phillyrin, a unique antiviral lignan exclusive to Forsythia suspensa , shows potent anti-influenza activity. However, its broad pharmaceutical application is hindered by low and variable natural accumulation, underscoring the need to elucidate its biosynthetic pathway for sustainable production. In this study, we used an integrated metabolomic and transcriptomic approach to investigate tissue-specific phillyrin biosynthesis in F. suspensa . We identified two O -methyltransferases (FsE4MT01 and FsE4MT02) that catalyze the methylation of (+)-epipinoresinol to form phillygenin and a UDP-glycosyltransferase (FsP4′GT) that glucosylates phillygenin to yield phillyrin. Using recombinant proteins expressed in Escherichia coli , we validated their in vitro catalytic activities and determined their kinetic parameters. Molecular docking and site-directed mutagenesis of key residues further revealed the structural basis of their catalytic mechanisms. The in vivo functions of these enzymes were confirmed through heterologous expression in Nicotiana benthamiana and F. suspensa leaves. Importantly, by developing a transient leaf-expression system in F. suspensa , we demonstrated that overexpression of FsE4MTs and FsP4′GT substantially increased the production of phillygenin and phillyrin, respectively, whereas virus-induced gene silencing (VIGS) of these genes reduced the accumulation of the corresponding products. Notably, enhanced phillyrin production was also achieved by expressing FsE4MTs and FsP4′GT in the related species Forsythia × intermedia , highlighting the potential of these key enzymes for metabolic engineering. Our findings elucidate the terminal steps of phillyrin biosynthesis and provide a strategic foundation for engineering the sustainable production of this pharmaceutically valuable compound.
危险品化学品经营许可证（带存储）