Desenvolvimento e validação de fingerprint por cromatografia em camada delgada para o extrato hidroetanólico das folhas de Moringa oleifera

Abstract

Moringa oleifera Lam. is a small to medium-sized tree and one of 13 species belonging to the Moringaceae family of a single genus. Due to its wide and ancient popular use in different regions, this species has been studied for the treatment of various diseases. However, it is necessary to establish quality control parameters, since there is no monograph of this species in the Brazilian Pharmacopoeia. One of the parameters required in the quality control of herbal medicines is the characterization of the chromatographic profile and the quantitative analysis of the marker throughout the production chain. In this context, the present work aimed to develop and validate an analysis methodology by Thin Layer Chromatography for application in the quality control of the hydroethanolic extract of Moringa oleifera leaves. For that, authentic samples were used, collected at Escola Agrícola de Jundiaí and which underwent different treatments: processed in liquid nitrogen “quenching” and dried in an oven at 40 °C. The commercial sample of dry leaves used was obtained from the commercial center of Natal - Rio Grande do Norte. The markers used were isovitexin and vitexin, flavonoids that have already been identified in this species. The method was developed focusing on the characterization of the flavonoid profile, as a qualitative identification method. In this way, several mobile phases were tested to obtain a chromatogram with a satisfactory chromatographic profile. The mobile phase chosen was composed of ethyl acetate: acetone: acetic acid: water (60:20:15:10, v/v/v/v). The parameters evaluated were selectivity, precision and robustness, following the standards recommended by RDC 166/2017. For the selectivity parameter, authentic samples, commercial samples and commercial standards were used. The same chromatographic profiles were observed for the authentic samples, however the commercial sample showed a different profile. From the results obtained, it can be concluded that the method is selective, as it allowed detecting a chromatographic profile different from the profiles found for the authentic samples and allowed the separation of the bands of interest, which are the standards. For the precision parameter, repeatability and intermediate precision were chosen. IN nº4, of 2014 recommends that the DPR (%) between the analyzes be less than 15%. The method was considered accurate because it met this specification. For the robustness parameter, small changes were made in some chromatographic conditions, being used as acceptance criterion the variability ≤ 0.1 for the results of the retention factor. The method was considered robust, as all retention factors were within the proposed range. Therefore, the method developed and validated by CCD to characterize the flavonoid profile and fingerprint of the hydroethanolic extract of Moringa oleifera leaves proved to be selective, accurate and robust.