**5. Conclusion**

138 Macro to Nano Spectroscopy

Chlorogen ic Acid

Caffeic Acid

L 49.1 ± 3.5 67.6 ± 0.3 2286 ± 80 nd nd nd nd

T B 5.1 ± 0.2 35.5 ± 0.2 nd nd 221 ± 20 nd nd

T B 5.9 ± 0.16 53.2 ± 1.2 nd nd 7.5 ±0.6 nd nd

T B 16.4 ± 2.2 7.9 ± 1.3 67 ± 2 nd 59.3 ± 2.2 182 ± 42 nd

R B 69 ± 1.4 792 ± 7 113.4 ± 1.4 149.9 ± 2.6 1833 ± 4.6 nd nd

L 7.5 ± 0.44 10.1 ± 0.7 79 ± 1.7 nd 31.9 ± 2.15 31.5 ± 1.1 nd

L nd 53 ± 0.4 683 ± 20.1 43.5 ±1.4 nd nd nd

Table 3. Concentrations of flavonoids and phenolic acids in the medicinal traditional plant

The results obtained by ABTS and DPPH tests show that the antioxidant activity order for these different plant parts was approximately similar in both assays. However, the antioxidant capacity using DPPH compared to the one obtained by ABTS essay was underestimated about 33%. Arnao, (2000) and Delgado-Andrade et *al*., (2005) report the same occurrence and they explain that the DPPH is only dissolved in alcoholic media. In contrast, the ABTS radicals being solubilised in aqueous and in organic media the antioxidant activity measured is due to the hydrophilic and lipophilic nature of the compounds. In addition, at 515 nm near the visible region where the antioxidant activity is

In this study, we found that phenolic compounds are the major contributors to the antioxidant activity, since total phenolics and antioxidant activity showed a good correlation with a correlation coefficient of R2=0.9208. However, we note that the trunk barks of *A. leiocarpus* exhibit a high antioxidant activity and a low level of total phenol antioxidant. The value of correlation coefficient between total flavonoids and antioxidant activity was R2 =

These results showing good antioxidant activity of these plant parts are particularly interesting since the antioxidant agents would induce analgesic, anticarcinogenic, anti-

R B nd 26 ± 1.2 62.1 ± 0.5 nd 4.2 ± 0.2 nd 70.9 ± 0.5

*p*coumaric Acid

Isovitexin Quercetin

Plant Plant

*Anogeissus leiocarpus* 

*Cissus populnea* 

*Mitragyna inermis* 

*Terminalia macroptera* 

*Vepris heterophylla* 

*Zizyphus mucronata* 

0.752 only.

parts

Gallic Acid

L= leaves; TB= trunk barks; RB= root barks; nd= not detected.

measured, interferences occur with the DPPH coloration.

parts (mg / 100g of dry material)

Protocatec huic Acid

> This study permits to evaluate the amount of phenolics, flavonoids and their total antioxidant activity linked to six traditional medicinal plants. Antioxidant activity varied greatly among the different plant parts and was highly correlated with the polyphenolic contents. We take an interest in the leaves of *A.Leocarpus* and in the root barks of *T.Macroptera*, since they exhibited important antioxidant activities and could be attractive sources of natural antioxidants. Moreover, this comparative study permits to identify and determine by RP-HPLC, five individual phenolic acids and two flavonoids that are mainly at the origin of the antioxidant activity in the studied plant parts.
