Abstract:

Aim To modify the structure of resibufogenin by using Ginkgo biloba suspension. Methods Young leaves of Ginkgo biloba were dedifferentiated into callus in MS medium with only 2,4-D as plant growth regulator. The callus was then transferred aseptically to liquid MS medium exogenously supplemented with appropriate concentration of 6-BA, NAA and 2,4-D to establish suspension cell culture system. Resibufogenin was administered into the well-grown cell cultures and incubated for 4 d. The products dissolved in the liquid phase of the cultures were extracted and purified by silica gel column chromatography gradiently eluted with petroleum ether and acetone system. Results One transformed product was obtained in 40% yield after 4 d incubation, which was identified as 3-epi-resibufogenin on the basis of FAB MS, ¹H NMR and ¹³C NMR spectroscopic analysis and corresponding data reported in literature. Conclusion G. biloba suspension cultures can be used as an enzyme system to biotransform resibufogenin, an animal-originated bufadienolide, into 3-epi-resibufogenin.

Key words: resibufogenin, resibufogenin, isomerization, isomerization, cell suspension cultu res, cell suspension cultu res, Ginkgo biloba, Ginkgo biloba