Antimalarial constituents from Nauclea orientalis (L.) L

Area of Science:

• Natural Product Chemistry
• Medicinal Chemistry
• Pharmacognosy

Background:

• Nauclea orientalis (Rubiaceae) is a plant with a history of traditional medicinal use.
• The search for novel antimalarial compounds is crucial due to increasing drug resistance.

Purpose of the Study:

• To isolate and characterize bioactive compounds from Nauclea orientalis with potential antimalarial activity.
• To evaluate the in vitro antimalarial efficacy of isolated compounds against Plasmodium falciparum.

Main Methods:

• Bioassay-guided fractionation of the CHCl3 extract of Nauclea orientalis stem.
• Structure elucidation using spectroscopic methods, including 1D and 2D-NMR analysis.
• In vitro testing against Plasmodium falciparum.

Main Results:

• Isolation of two novel tetrahydro-beta-carboline monoterpene alkaloid glucosides: naucleaorine and epimethoxynaucleaorine.
• Identification of known compounds: strictosidine lactam, 3,4,5-trimethoxyphenol, and several ursane and oleanane triterpenoids.
• Compounds naucleaorine, epimethoxynaucleaorine, and two known compounds (strictosidine lactam and oleanolic acid) exhibited moderate in vitro antimalarial activity.

Conclusions:

• Nauclea orientalis is a source of novel bioactive alkaloids with antimalarial potential.
• The isolated compounds, particularly naucleaorine and epimethoxynaucleaorine, warrant further investigation as leads for antimalarial drug development.
• Spectroscopic methods were effective in determining the structures and configurations of the isolated compounds.