Indole glucoalkaloids from Chimarrhis turbinata and their evaluation as antioxidant agents and acetylcholinesterase inhibitors

J Nat Prod. 2004 Nov;67(11):1882-5. doi: 10.1021/np049863m.

Abstract

As part of our study on bioactive agents from Brazilian rainforest plants, two new glucoalkaloids, 3,4-dehydro-strictosidine (1) and 3,4-dehydro-strictosidinic acid (2), were isolated from Chimarrhis turbinata, along with seven known glucoalkaloids, cordifoline (3), strictosidinic acid (4), strictosidine (5), 5 alpha-carboxystrictosidine (6), turbinatine (7), desoxycordifoline (8), and harman-3-carboxylic acid (9). The structures of the new alkaloids were established on the basis of comprehensive spectral analysis, mainly 1D and 2D NMR experiments, as well as high-resolution HRESIMS. Alkaloid 3 showed strong free-radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) as well as pronounced antioxidant activity evidenced by redox properties measured by ElCD-HPLC. Additionally, alkaloids 1-9 were submitted to TLC screening for acetylcholinesterase inhibitors. Both 7 and 8 were shown to be moderate acetylcholinesterase inhibitors at a concentration of 0.1 and 1.0 microM, respectively. In an in vitro rat brain assay, 7 showed moderate activity (IC(50) 1.86 microM), compared to the standard compound, galanthamine (IC(50) 0.92 microM).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antioxidants / chemistry
  • Antioxidants / isolation & purification*
  • Antioxidants / pharmacology
  • Brain / metabolism
  • Brazil
  • Cholinesterase Inhibitors / chemistry
  • Cholinesterase Inhibitors / isolation & purification*
  • Cholinesterase Inhibitors / pharmacology
  • Indole Alkaloids / chemistry
  • Indole Alkaloids / isolation & purification*
  • Indole Alkaloids / pharmacology
  • Inhibitory Concentration 50
  • Molecular Structure
  • Oxidation-Reduction
  • Rats
  • Rubiaceae / chemistry*

Substances

  • 3,4-dehydro-strictosidine
  • 3,4-dehydro-strictosidinic acid
  • Antioxidants
  • Cholinesterase Inhibitors
  • Indole Alkaloids