Isolation and characterization of xylopic acid from Xylopia aethiopica and its antioxidant properties

                        Avoseh, Opeyemi N.O., Odesanya, Olaide G., Akpovwovwo Efetobore, I., Department of Chemistry, Faculty of Science, Lagos State University,                                                                                     LASU P.O Box 0001, Ojo, Lagos, Nigeria.

 

   INTRODUCTION

  X. aethiopica also known as negro pepper, uririẹn, eeru alamo, uda and chimba is from the family Annonaceae. Traditionally, it is used by locals to combat malaria, for cosmetics, as a natural as a birth control measure, and preservative1 . The n-hexane and methanol extracts of inhibits the cervical cancer cell line (C-33A). It shows anti-inflammatory activity by inhibiting the proliferation of the histamine, serotonin, bradykinin and prostaglandin in-vivo2 . Antioxidants are natural molecules that neutralizes harmful free radicals in the body. Oxygen derived (ROS) include superoxide anion (O2 ), hydrogen peroxide (H2O2 ), peroxyl radicals (ROO) and reactive hydroxyl radicals (OH). The nitrogen derived free radicals are nitric oxide (NO), peroxy nitrite anion (ONOO), Nitrogen dioxide (NO2 ) and Dinitrogen trioxide (N2O3 ).

 AIM OF STUDY

   The research focus on the isolation of Xylopic acid from X. aethiopica and their antioxidant properties.

RESULTS AND DISCUSSION

  The ethyl acetate extract of X. aethiopica gives a yield of 5.0 g and its TLC chromatographic separation yield more components .Three isolates were purified from the Column chromatography from f12-16 , f17-20 and f167- 204 . A white crystalline compound obtained from f12-16 with a yield of 0.5 g; M.pt; 206- 210 oC was further characterized using FTIR, melting point and NMR. The FTIR shows an -OH band at 3257 cm-1 , CH stretch of CH3 at 2929 cm-1 , -C=O at 1606 cm-1 and -C-O at 1036 cm-1 . The 1H-NMR shows carboxylic -OH at 12.01 ppm, terminal –C=C at 4.92 ppm and 4.77 ppm and α-H at 2.07 ppm3 . 13C-NMR reveals signals for CH-, CH2 , CH3 , C-O.

CONCLUSION

  Extracts from X. aethiopica have shown to have antioxidant property. The study also indicated that xylopic acid isolated from the ethyl acetate extract of X.aethiopica exhibited antioxidant activity.  The study confirms the ethno-pharmacological basis of the uses of X. aethiopica.