Improved procedure for the quality control of Hypericum perforatum L

Area of Science:

• Phytochemistry
• Analytical Chemistry
• Pharmacognosy

Background:

• Hypericum perforatum L. (St. John's Wort) contains valuable bioactive compounds.
• Accurate quantification of naphthodianthrones and phloroglucinols is essential for quality control and research.
• Previous extraction and quantification methods may be time-consuming or inefficient.

Purpose of the Study:

• To develop a rapid, reliable HPLC procedure for quantifying major compounds in Hypericum perforatum.
• To optimize extraction methods for naphthodianthrones (hypericins) and phloroglucinols (hyperforins).
• To assess the stability of these compounds under different conditions, including light exposure.

Main Methods:

• High-Performance Liquid Chromatography (HPLC) with a 17-minute linear gradient was employed.
• Quantification utilized hypericin and hyperforin as external standards.
• Two sequential extraction methods were tested: methanol extraction at room temperature and water:ethanol extraction at 80°C.

Main Results:

• A combined extraction approach achieved complete recovery of hypericins and hyperforins.
• Methanol extraction efficiently recovered phloroglucinols but not naphthodianthrones.
• Heat extraction yielded total hypericins but caused a 10% loss of hyperforins.
• Hyperforins degraded significantly upon light exposure, especially in crude extracts.

Conclusions:

• A validated, fast HPLC method enables accurate quantification of key Hypericum perforatum constituents.
• Sequential extraction optimizes the recovery of both naphthodianthrones and phloroglucinols.
• Hyperforins are highly sensitive to light, necessitating careful handling during processing and storage.