Alkaloids and Iridoids From Phlogacanthus curviflorus

Area of Science:

• Natural Product Chemistry
• Pharmacology
• Medicinal Chemistry

Background:

• Phlogacanthus curviflorus is a plant source of bioactive compounds.
• The genus Phlogacanthus has not been previously reported to contain alkaloids.
• Investigating novel compounds from medicinal plants is crucial for drug discovery.

Purpose of the Study:

• To isolate and characterize new chemical constituents from Phlogacanthus curviflorus.
• To evaluate the biological activities of the isolated compounds, including α-glucosidase inhibition, NO production, antioxidant, and cytotoxic effects.
• To assess the antifibrotic potential of the isolated alkaloids.

Main Methods:

• Phytochemical investigation of Phlogacanthus curviflorus twigs and leaves.
• Structure elucidation using Mass Spectrometry (MS) and Nuclear Magnetic Resonance (NMR) data.
• Absolute configuration determination via electronic circular dichroism (ECD) spectra comparison.
• In vitro assays for α-glucosidase inhibition, NO production, antioxidant activity, cytotoxicity, and antifibrotic effects.

Main Results:

• Four new pyridine alkaloids (curviflorines A-D) and two new iridoids (curviridoids A and B) were isolated, along with one known iridoid glycoside.
• This marks the first report of alkaloidal constituents from the genus Phlogacanthus.
• Compounds 1-7 showed no significant inhibitory activity against α-glucosidase, NO production, antioxidant activity, or cytotoxicity against tested cancer cell lines.
• Alkaloids 1-4 demonstrated a significant suppressive effect on TGF-β1-induced fibronectin upregulation in HK-2 cells.

Conclusions:

• The study successfully identified novel alkaloids and iridoids from Phlogacanthus curviflorus.
• The isolated alkaloids (1-4) exhibit promising antifibrotic potential by inhibiting fibronectin expression.
• Further research into these alkaloids could lead to the development of new antifibrotic therapies.