QUANTIFICATION OF XYLOPIC ACID AND CHROMATOGRAPHIC FINGERPRINT EVALUATIONS OF THE DRIED FRUITS OF XYLOPIA AETHIOPICA   FROM FOUR AFRICAN COUNTRIES

Background: The fruits of Xylopia aethiopica (Dunal) A. Rich, (herein called XYA), family Annonaceae, commonly known as “Guinea pepper”, “Ethiopian pepper” or “Negro pepper”, are widely used in traditional African medicines to treat a wide array of diseases including malaria, fungal infections, rheumatism, arthritis, etc. Scientific investigations have ascribed the following activities to the fruits of XYA; anti-diabetic, anti-inflammatory, antimicrobial, antiplasmodial, analgesic, anti-nociceptive, anti-proliferative, spermatogenic and neuropharmacological effects. The main active principle reported is xylopic acid (XA), a kaurene diterpene. This study aimed to develop and validate a simple HPLC/UV (high performance liquid chromatography – ultraviolet detection) analytical method for the quantification of XA that can be reproduced in poor-resource settings where advanced analytical detection techniques such as HPLC-MS are unavailable.
Materials and Methods: Thus in this study, a simple C18 solid-phase extraction (SPE) column-pretreatment ─ HPLC/UV analytical procedure was developed for the quantification of XA in the dried fruits of XYA from four African countries, Benin, Cameroon, Ghana and Nigeria. The samples of XYA from the four countries were assessed for similarities using chromatographic fingerprinting.
Results: The HPLC method was validated for linearity, limits of detection and quantification, precision and accuracy. The samples of XYA from Cameroon were found to have the highest average content of XA while those from Benin had the lowest average content of XA.
Conclusion: Using the chromatographic fingerprint evaluation, the similarities of the samples from the four countries to the reference chromatogram was in the order: Benin > Cameroon > Nigeria > Ghana.

Keywords
Xylopia aethiopica; xylopic acid; C18 solid-phase extraction (SPE) pre-treatment; HPLC/UV; chromatographic fingerprint evaluation