Apoprunellelactone (APL), an antiprotozoal lactone from the stem barks of Isolona cooperi Hutch. & Dalziel (Annonaceae)

Abstract

Bioassay guided fractionation of the stem barks of Isolona cooperi led to the isolation of a new lactone, apoprunellelactone (APL, 1), and two known compounds, 5-[1-hydroxyhexyl]-2H-furan-2-one (2) and oleic acid (3). Their structures were elucidated by spectral analysis including MS, UV, IR, 1D and 2D-NMR spectroscopy. Evaluated for its antiprotozoal activities, APL (1) was found to be the most active on Leishmania donovani and L. major promastigotes with EC₅₀ values of 16.3 and 8.2 µM, respectively. Against Trypanosoma brucei brucei trypomastigote forms, the activity of APL was moderated (MEC = 38.0 µM). Its hemisynthetic ester acetic derivative (1c) was 2-42 times more active than that of the APL and reference drugs, justifying further in vivo evaluation of the two compounds (1 and 1c) on Leishmania sp and Trypanosoma brucei brucei/mice models.

Graphical Abstract

Keywords:

• Isolona cooperi
• Annonaceae
• lactones
• apoprunellelactone
• antiprotozoal activities

Acknowledgements

The authors are grateful to Dr Christian Bories for it input in this study and the CNF (Centre National de Floristique) of Félix Houphouët Boigny University, Cocody-Abidjan (Côte d’Ivoire), for identifying the plant material. This work was supported by the Ministry of Research of Ivory Coast and by the Centre National de la Recherche Scientifique in France.

Disclosure statement

The authors declare no conflict of interest.