Compounds from Toddalia asiatica: Immunosuppressant Activity and Absolute Configurations

J Nat Prod. 2020 Oct 23;83(10):3012-3020. doi: 10.1021/acs.jnatprod.0c00564. Epub 2020 Oct 1.

Abstract

In a screening of an extract library from plants used in Traditional Chinese Medicine the MeOH extract of Toddalia asiatica inhibited proliferation of human primary T cells with an IC50 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 (6) and both enantiomers (7a and 7b) of toddanolic acid (7), were new natural products, and two recently published compounds, (2'R)-toddalolactone 3'-O-β-d-glucopyranoside (10) and (2'S)-toddalolactone 2'-O-β-d-glucopyranoside (11), were described in detail for the first time. The absolute configurations of compounds 8, 9, 10, 12, 13, and 15 were determined by comparison of experimental and calculated ECD spectra. For glucosides 9 and 10, ECD data and chiral-phase HPLC of the aglycones after enzymatic hydrolysis confirmed the results. Nitidine chloride (4) inhibited proliferation of primary human T cells with an IC50 of 0.4 μM.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Coumarins
  • Glucosides
  • Immunosuppressive Agents / pharmacology*
  • Molecular Structure
  • Plant Extracts / pharmacology*
  • Plant Roots
  • Rutaceae*
  • Stereoisomerism

Substances

  • Coumarins
  • Glucosides
  • Immunosuppressive Agents
  • Plant Extracts
  • toddalolactone