Diarylheptanoid glycosides from Dioscorea nipponica rhizomes

Area of Science:

• Natural Product Chemistry
• Pharmacognosy
• Medicinal Chemistry

Background:

• Dioscorea nipponica, a traditional medicinal plant, is a rich source of bioactive compounds.
• Diarylheptanoids are a class of natural products with diverse pharmacological activities.
• Understanding the chemical constituents and bioactivity of D. nipponica is crucial for its therapeutic applications.

Purpose of the Study:

• To isolate and characterize novel diarylheptanoids from Dioscorea nipponica rhizomes.
• To evaluate the nitric oxide (NO) inhibitory potential of isolated compounds.

Main Methods:

• Isolation of compounds using chromatographic techniques.
• Structure elucidation via comprehensive spectroscopic analyses (UV, IR, HR-ESI-MS, NMR).
• Determination of absolute configurations using electronic circular dichroism (ECD) and optical rotation.
• Bioassay for NO inhibition using lipopolysaccharides-induced RAW 264.7 cells.

Main Results:

• Six new diarylheptosides, diodiarylheptosides A-F (1-6), and six known diarylheptanoids (7-12) were isolated.
• Structures were confirmed through detailed spectroscopic analysis and ECD calculations.
• Compounds 3 and 11 demonstrated notable NO inhibition with IC50 values of 14.91 ± 0.62 μM and 12.78 ± 1.12 μM, respectively.

Conclusions:

• The study successfully identified novel diarylheptanoids from Dioscorea nipponica.
• Compounds 3 and 11 possess significant nitric oxide inhibitory activity, suggesting potential anti-inflammatory effects.
• These findings contribute to the understanding of D. nipponica's chemical diversity and therapeutic potential.