¹³C NMR dereplication-assisted isolation of bioactive polyphenolic metabolites from Clusia flava Jacq.

Abstract

Presently it is estimated that many of the approximately 4000 new natural products isolated every year following complicated, long, and expensive isolation processes are already known; because of this, developing new strategies for locating secondary metabolites of interest in complex extracts or fractions is important. Currently, chromatographic and spectroscopic techniques are being used to optimize the isolation and identification of natural products. In this investigation we have used ¹³C NMR dereplication analyses for the quick identification of a number of triterpenes (friedelin, lupeol, betulinic acid), sterols (euphol, β-sitosterol) and fatty acids (palmitic acid) present in semipurified fractions obtained from the stem bark extract of Clusia flava and to assist in the isolation of the bioactive metabolites trapezifolixanthone and paralycolin A. The complete and correct assignment of the ¹H and ¹³C NMR spectroscopic data for paralycolin A is reported for the first time and the antioxidant and antiAGEs activity of both metabolites is described.

Keywords:

• Clusiaceae
• dereplication
• polyphenolic metabolites
• xanthone
• dihydrophenantrene

Acknowledgments

The authors wish to thank Gabriel Dzib for assisting in the collection of plant material; María Silvia Hernández-Aguilar for assisting in the preparation of herbarium samples; Karlina García-Sosa and Dimitri Bréard for technical assistance; José Manuel Cervantes Uc and Nayeli Rodríguez Fuentes assistance in the determination of antioxidant activity. LAHD wishes to thank CONACYT for scholarship No. 288061.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by SEP-CONACYT-ANUIES-ECOS-NORD (Mexico-France) collaborative Project No. 276520.