Quinoid glycosides from Forsythia suspensa

Area of Science:

• Natural Product Chemistry
• Pharmacology
• Virology

Background:

• Forsythia suspensa is a traditional medicinal plant.
• Viruses like influenza A and RSV pose significant public health challenges.
• Identifying novel antiviral agents is crucial for combating viral infections.

Purpose of the Study:

• To conduct a phytochemical investigation of Forsythia suspensa.
• To isolate and characterize compounds from the plant.
• To evaluate the antiviral activities of these compounds against influenza A (H1N1) and respiratory syncytial virus (RSV).

Main Methods:

• Phytochemical analysis using extensive spectroscopic data (IR, UV, HRESIMS, 1D NMR, 2D NMR).
• Structure elucidation and absolute configuration determination (ECD calculation, chemical degradation).
• In vitro antiviral assays against influenza A (H1N1) and RSV.

Main Results:

• Ten new compounds were isolated, including quinoid glycosides, lignan glycosides, phenylethanoid glycoside, and allylbenzene glycoside, along with 13 known compounds.
• Two previously identified compounds exhibited significant antiviral activity against RSV.
• EC50 values for the active compounds against RSV were determined as 3.43 μM and 6.72 μM.

Conclusions:

• Forsythia suspensa is a valuable source of bioactive phytochemicals.
• Two compounds from Forsythia suspensa show promising antiviral potential against RSV.
• Further research into these compounds could lead to new therapeutic strategies for RSV infections.