Iridal-type triterpenoids with ichthyotoxic activity from belamcanda chinensis

Area of Science:

• Natural Product Chemistry
• Pharmacognosy
• Marine Biology

Background:

• Belamcanda chinensis (Iridaceae) is a plant with a history of traditional medicinal use.
• Triterpenoids are a diverse class of natural products with a wide range of biological activities.
• Ichthyotoxicity, the toxicity to fish, is an important characteristic for evaluating natural compounds.

Purpose of the Study:

• To isolate and characterize iridal-type triterpenoids from Belamcanda chinensis extracts.
• To evaluate the ichthyotoxic activity of the isolated compounds against killifish (Oryzias latipes).

Main Methods:

• Activity-guided fractionation of hexane and ether extracts of Belamcanda chinensis.
• Structure elucidation of isolated compounds using spectral (NMR, MS) and chemical methods.
• Determination of absolute configuration using the modified Mosher's method.
• Ichthyotoxicity assays using killifish (Oryzias latipes).

Main Results:

• Eleven iridal-type triterpenoids were isolated, including six new compounds: 3-O-tetradecanoyl-16-O-acetylisoiridogermanal (4), 3-O-decanoyl-16-O-acetylisoiridogermanal (5), belachinal (7), anhydrobelachinal (9), epianhydrobelachinal (10), and isoanhydrobelachinal (11).
• The absolute configuration of isoiridogermanal (1) at C-16 was determined as R.
• 16-O-acetylisoiridogermanal (3), belachinal (7), and spiroiridal (12) demonstrated potent ichthyotoxic activity.

Conclusions:

• Belamcanda chinensis is a rich source of iridal-type triterpenoids with significant ichthyotoxic properties.
• The identified compounds, particularly 16-O-acetylisoiridogermanal, belachinal, and spiroiridal, warrant further investigation for potential applications.
• This study contributes to the understanding of the chemical diversity and bioactivity of Belamcanda chinensis.