Three novel pterosin dimers form Pteris obtusiloba

Area of Science:

• Natural Product Chemistry
• Pharmacognosy
• Medicinal Chemistry

Background:

• Pteris obtusiloba is a fern species known to contain various bioactive compounds.
• Pterosins are a class of natural products with diverse biological activities.
• Understanding the chemical constituents of medicinal plants is crucial for drug discovery.

Purpose of the Study:

• To isolate and characterize novel pterosin dimers from Pteris obtusiloba.
• To evaluate the cytotoxic and α-glucosidase inhibitory activities of the isolated compounds.
• To explore the potential of these natural products as therapeutic agents.

Main Methods:

• Isolation of compounds using chromatographic techniques.
• Structure elucidation employing ESI-MS, 1D/2D NMR, CD, and X-ray crystallography.
• Assessment of cytotoxic activity against HCT-116 cell line.
• Evaluation of α-glucosidase inhibition activity.

Main Results:

• Three novel pterosin dimers (obtupterosin A, B, and C) and eight known pterosins were isolated.
• Compounds 1 and 2 were identified as isomers, while 1 and 3 represented a new dimer type.
• Compounds 1-3 demonstrated cytotoxic effects against HCT-116 cells with IC50 values ranging from 12.8 to 30.6 μM.
• None of the new compounds showed significant α-glucosidase inhibition at 200 μM.

Conclusions:

• Pteris obtusiloba is a source of novel pterosin dimers with notable cytotoxic potential.
• The isolated compounds, particularly obtupterosin C, warrant further investigation for anticancer drug development.
• The lack of α-glucosidase inhibition suggests specific mechanisms of action for these compounds.