Optimized Kaempferitrin Isolation from Uncaria guianensis Leaves by Solid-Phase Extraction

Abstract

A simple and low-cost solid-phase extraction methodology for isolating the bioactive flavonoid kaempferitrin from a defatted fraction of the Uncaria guianensis leaf ethanol extract was developed using the kaempferitrin retention behavior in reversed-phase-high-performance liquid chromatography as well as thin-layer chromatography coupled to ImageJ software (Bethesda, USA) for densitometric analyses. In addition, the method enabled the isolation of less-complex mixtures for the further separation of minor constituents. The target compound was successfully isolated from 1 to 5 mg of the fraction per 500 mg C18 cartridge using 6 mL of 15% acetonitrile at 60% relative recovery and 99% purity.

Keywords:

• densitometry
• HPLC
• kaempferitrin
• solid-phase extraction
• TLC
• Uncaria guianensis

Acknowledgments

The authors thank Dr. Peter May and NGO Pro-Natura (Brazil) for the kind donation of the plant material, Dr. Hélida B. N. Borges from the Central Herbarium of the UFMT, Brazil for cooperation, and also thank Prof. Luiz Nelson L. F. Gomes from Chemistry Institute of the UFRJ (Brazil) for the valuable comments and suggestions.

Notes

Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/ljlc.