Two new bioactive iridoids from Rothmannia wittii

Area of Science:

• Natural Product Chemistry
• Pharmacology

Background:

• Rothmannia wittii is a plant species with potential medicinal properties.
• Phytochemical investigation of medicinal plants is crucial for discovering novel therapeutic compounds.

Purpose of the Study:

• To isolate and identify chemical constituents from the bark and fruit of Rothmannia wittii.
• To evaluate the biological activities of the isolated compounds.

Main Methods:

• Compounds were isolated using chromatographic techniques.
• Structural elucidation was performed using various spectroscopic methods (e.g., NMR, MS).
• Biological activities, including antimycobacterial and cytotoxic effects, were assessed using standard assays.

Main Results:

• Two new iridoids, 6β-hydroxy-10-O-acetylgenipin (1) and 10-O-acetylmacrophyllide (2), were identified.
• Six known iridoids, benzoic acid, vanillic acid, and stigmasterol were also isolated.
• Iridoid 1 demonstrated antimycobacterial activity against Mycobacterium tuberculosis (MIC = 12.50 μg/mL).
• Iridoid 2 showed cytotoxicity against the NCI-H187 cancer cell line (IC50 = 6.82 μg/mL).
• Compounds 2 and 5 exhibited weak cytotoxicity against KB and MCF-7 cell lines, while compound 4 was active against NCI-H187.

Conclusions:

• Rothmannia wittii is a source of novel iridoids with significant biological activities.
• The isolated compounds, particularly iridoids 1 and 2, show potential for development as therapeutic agents against tuberculosis and cancer.