Two new bisindole alkaloids from Tabernaemontana macrocarpa Jack

Area of Science:

• Natural Product Chemistry
• Medicinal Chemistry
• Pharmacology

Background:

• Tabernaemontana macrocarpa Jack is a plant source of bioactive compounds.
• Bisindole alkaloids represent a class of natural products with diverse pharmacological properties.

Purpose of the Study:

• To isolate and characterize new bisindole alkaloids from Tabernaemontana macrocarpa Jack.
• To evaluate the antimalarial potential of the isolated compounds.

Main Methods:

• Isolation of alkaloids using chromatographic techniques.
• Structure elucidation via extensive spectroscopic methods (NMR, MS) and chemical correlation.
• Determination of absolute configurations using Time-Dependent Density Functional Theory (TDDFT) calculations and Electronic Circular Dichroism (ECD).
• In vitro antimalarial activity assay against Plasmodium falciparum (3D7 strain).

Main Results:

• Two new bisindole alkaloids, bisnaecarpamines A (1) and B (2), were identified.
• The vobasine-sarpagine type skeleton of the new compounds was confirmed.
• Absolute configurations for compounds 1 and 2 were successfully determined.
• Bisnaecarpamine A demonstrated potent antimalarial activity with an IC50 of 28.8 µM against Plasmodium falciparum 3D7.

Conclusions:

• The study successfully isolated and characterized two novel bisindole alkaloids.
• Bisnaecarpamine A is a promising candidate for further antimalarial drug development.
• The findings contribute to the understanding of chemical diversity in Tabernaemontana species.