Compounds from : Immunosuppressant Activity and Absolute Configurations.

In a screening of an extract library from plants used in Traditional Chinese Medicine the MeOH extract of inhibited proliferation of human primary T cells with an IC of 25.8 μg/mL. Activity in the extract was tracked by HPLC activity profiling, and a total of 15 compounds were characterized. Three compounds, toddalic acid () and both enantiomers ( and ) of toddanolic acid (), were new natural products, and two recently published compounds, (2')-toddalolactone 3'--β-d-glucopyranoside () and (2')-toddalolactone 2'--β-d-glucopyranoside (), were described in detail for the first time. The absolute configurations of compounds , , , , , and were determined by comparison of experimental and calculated ECD spectra. For glucosides and , ECD data and chiral-phase HPLC of the aglycones after enzymatic hydrolysis confirmed the results. Nitidine chloride () inhibited proliferation of primary human T cells with an IC of 0.4 μM.