A new cytochalasin from endophytic Phomopsis sp. IFB-E060

Area of Science:

• Natural Product Chemistry
• Mycology
• Pharmacology

Background:

• Endophytic fungi, such as Phomopsis sp., are a rich source of novel bioactive compounds.
• Vatica mangachapoi harbors diverse endophytic microorganisms with potential medicinal properties.

Purpose of the Study:

• To isolate and characterize chemical constituents from the solid culture of the endophytic Phomopsis sp. IFB-E060.
• To evaluate the cytotoxic activity of the isolated compounds against the human hepatocarcinoma cell line SMMC-7721.

Main Methods:

• Silica gel column chromatography, Sephadex LH-20 gel filtration, ODS column chromatography, and HPLC were used for isolation and purification.
• Spectroscopic analyses including UV, CD, IR, MS, 1D, and 2D NMR were employed for structure elucidation.
• In vitro cytotoxicity was assessed using the MTT assay against SMMC-7721 cells.

Main Results:

• Five compounds were isolated: 18-methoxy cytochalasin J (1), cytochalasin H (2), (22E, 24S)-cerevisterol (3), ergosterol (4), and nicotinic acid (5).
• 18-Methoxy cytochalasin J (1) exhibited an inhibition rate of 24.4% at 10 μg·mL⁻¹.
• Cytochalasin H (2) showed an IC50 value of 15.0 μg·mL⁻¹ against SMMC-7721 cells.

Conclusions:

• 18-Methoxy cytochalasin J (1) is a novel cytochalasin isolated from endophytic Phomopsis sp. IFB-E060.
• The new cytochalasin demonstrated weak cytotoxicity against the human hepatocarcinoma cell line SMMC-7721.