Z0 ion from saikosaponins with 16 α‐OH and Y0‐H2O from saikosaponins with 16 β‐OH may underlie their different dissociation patterns of [aglycone − H2O + H]+.

Z₀ ion from saikosaponins with 16 -OH and Y₀-H₂O from saikosaponins with 16 -OH may underlie their different dissociation patterns of [aglycone - H₂O + H]⁺ Epimers are ubiquitous in natural products, among which SSa and SSd are a typical pair of epimers in the I Bupleurum i species. Above all, the [aglycone - H SB 2 sb O + H] SP + sp ion at I m/z i 455.35(C SB 30 sb H SB 47 sb O SB 3 sb ) of SSa and SSd in the full-scan mass spectra should mainly be the I Y i SB 0 sb -H SB 2 sb O ion and I Z i SB 0 sb ion, separately, and this may underlie their different dissociation patterns. [Extracted from the article]