Immunomodulatory effect and quantitation of a cytotoxic glycosphingolipid from Murdannia loriformis

NMR signal reassignments for a cytotoxic glycosphingolipid compound, 2, β-O-D-glucopyranosyl-2-(2'-hydroxy-Z-6'-enecosamide)sphingosine, isolated from an ethanolic extract of the herb Murdannia loriformis, have been achieved by use of FAB-MS, and 1D and 2D ¹H and ¹³C NMR. The amount of 2 in the herb juice was quantitatively determined by use of a validated HPLC method (RP-18, MeOH-H₂O, UV detection at 210 nm). The immunomodulatory effect of the herb juice and of 2 was proved by means of in vitro cellular immunological assays. Compound 2 at a concentration of 13 nmol L^-1 stimulated PBMC proliferation and increased the CD 3,4:CD 3,8 ratio in T lymphocytes.