Isolation and Determination of Iridoid Glycosides from the Seeds of Osmanthus fragrans by HPLC

Abstract

Osmanthus fragrans is a traditional economic and ornamental plant in China. Iridoid glycosides are one of the main active ingredients of this plant. The ethanol extract of O. fragrans’ seeds was analyzed by an HPLC method. The HPLC profile allowed the isolation of nuzhenide and GI-3 from O. fragrans’ seeds for the first time. A C18 column was used with a mixture of methanol and water as the mobile phase using a gradient elution technique. Nuzhenide and GI-3 as the major components were used successfully as chemical markers to determine the optimal time of O. fragrans’ seeds for collection. Experimental results show nuzhenide and GI-3 reached the highest level in the last ten days of April, with contents of 6.04 mg (g of dw)⁻¹ and 13.24 mg (g of dw)⁻¹, higher than that of olive seeds. The study showed that O. fragrans’ seeds can serve as a source of iridoid glycosides.

Keywords:

• Content variation
• GI-3
• Iridoid glycosides
• Nuzhenide
• Osmanthus fragrans’ seeds
• Quantification

Acknowledgments

This study is supported by 973 projects (No. 2011CB512005), the National Natural Science Foundation of China (No. 81260472, 21101035), the Natural Science Foundation of Guangxi Province (No. 2012GXNSFAA053027, 2010GXNSFF013001, 2011GXNSFD018010, and 2007228) and the projects of the Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Guangxi Normal University), Ministry of Education of China (CMEMR2011-15).

Notes

*Y = peak area; X = content (µg).