Polyanthumin, a novel cyclobutane chalcone trimmer from Memecylon polyanthum

Area of Science:

• Natural Product Chemistry
• Phytochemistry
• Medicinal Chemistry

Background:

• Memecylon polyanthum stems are a source of bioactive natural products.
• Chalcones and flavonoids are classes of compounds with known biological activities.
• The Melastomataceae family is underexplored for specific flavonoid subclasses.

Purpose of the Study:

• To isolate and characterize novel and known compounds from Memecylon polyanthum.
• To investigate the antitumor potential of isolated compounds against human cancer cell lines.
• To report the first instance of specific flavonoids from the Melastomataceae family.

Main Methods:

• Isolation and structural elucidation of compounds using chromatographic and spectroscopic techniques.
• In vitro antitumor activity assay using the Sulforhodamine B (SRB) method.
• Determination of half-maximal inhibitory concentration (IC50) values for active compounds.

Main Results:

• Isolation of a novel chalcone trimer, polyanthumin (1), and five known compounds (2-6).
• Compounds 3 and 4 represent the first reported flavonoids with a single 7-OH in the A ring from the Melastomataceae family.
• Compounds 2-4 exhibited antitumor activity for the first time, with inhibition rates of 39.4%–54.5% and IC50 values of 45.4 μg/ml (1) and 30.5 μg/ml (3) against K562 cells.

Conclusions:

• Memecylon polyanthum is a source of structurally unique compounds, including the novel chalcone trimer polyanthumin.
• The isolated compounds demonstrate potential as antitumor agents, warranting further investigation.
• This study expands the known chemical diversity and biological activity of compounds from the Melastomataceae family.