Immunosuppressive constituents from Saussurea medusa

The methanol extract of Saussurea medusa Maxim afforded two lignans: 2α-guaicyl-4-oxo-6α-catechyl-3,7-dioxabicyclo [3.3.0]octane and 1α-hydroxy-2α,4α-guaicyl-3,7-dioxabicyclo[3.3.0]octane; two chlorophyll derivatives: 13-epi-phaeophorbide-a and 13-epi-phaeophorbide-a methyl ester; one megastigmane derivative: 3β-hydroxy-5α,6α-epoxy-7-megastigmen-9-one, along with 19 known compounds. Their structures were established on the basis of spectroscopic studies.