[Meroterpenoids from Rhododendron nivale]

Area of Science:

• Natural Product Chemistry
• Phytochemistry
• Medicinal Chemistry

Context:

• Rhododendron nivale is a plant species with potential medicinal properties.
• Understanding its chemical constituents is crucial for exploring its therapeutic applications.
• Meroterpenoids are complex natural products with diverse biological activities.

Purpose:

• To isolate and characterize new meroterpenoid enantiomers from Rhododendron nivale.
• To evaluate the neuroprotective activity of these isolated compounds.
• To elucidate the chemical material basis of R. nivale.

Summary:

• Five new meroterpenoid enantiomers, (±)-nivalones A-B and (±)-nivalnoids C-D, along with a known compound, were isolated from Rhododendron nivale using chromatographic techniques.
• Structural elucidation was performed using high-resolution mass spectrometry (HRMS), nuclear magnetic resonance (NMR) spectroscopy, and electronic circular dichroism (ECD).
• Neuroprotective effects were assessed using hydrogen peroxide (H2O2)-induced oxidative stress in human neuroblastoma (SH-SY5Y) cells.

Impact:

• Compounds (±)-nivalone B (2a) and (±)-nivalnoid C (3a) exhibited significant protective effects against H2O2-induced oxidative damage in SH-SY5Y cells.
• These findings expand the knowledge of R. nivale's chemical diversity and meroterpenoid structures.
• The study provides valuable insights into the potential neuroprotective properties of R. nivale constituents.