Terpenos de culturas in vitro de Duroia saccifera (Rubiaceae) e avaliação das atividades antibacteriana, antiangiogênica e antioxidante dos extratos

Abstract

Duroia saccifera (Mart. Ex Roem. & Schult.) K. Schum. (Rubiaceae) occurs in the Amazon rainforest. In natura plant extracts of the species have shown antioxidant, antimicrobial even against Mycobacterium tuberculosis activity, showing their medicinal potential. Based on this, the objective of this work was to study phytochemically and some biological activities of extracts of in vitro D. saccifera cultures, as well as to describe differences involved in in vitro propagation methods and calogenesis induction time, based on the chemical profile of the extracts hexanes, ethyl acetate (EtOAc) and methanolic (MeOH) from seedlings, calli, and cell suspensions. Seedlings of D. saccifera were used to prepare seedling extracts and as a source of explants to initiate the establishment of callus and cell suspension cultures. The plant material was extracted with the organic solvents hexane, EtOAc and MeOH. Callus EtOAc and seedling MeOH extracts were fractionated in open column. All extracts and fractions were analyzed by Comparative Thin Layer Chromatography (TLC). Callus extracts and suspensions were tested in antimicrobial and antioxidant assays; cell suspension extracts were tested for angiogenic activity. Callus extracts and cell suspensions had a similar chemical profile, and the seedling extracts were remarkably different, however, all extracts were rich in terpenoids. The comparison of the chemical profile of the extracts of the cultures and explants with different degrees of differentiation made it possible to verify the presence of iridoids only in cultures with differentiated cells. A mixture of β-sitosterol, stigmasterol and oleanolic and ursolic acid were obtained from the EtOAc extract. Seedling fractionation resulted in the isolation of the iridoid monotropein methyl ester, obtained for the first time in the species. Of the extracts tested, the EtOAc extracts of callus and suspensions and hexanic callus extract showed bacteriostatic activity. EtOAc extract from cell suspensions showed significant antiagiogenic activity. The results found in this work demonstrate the great potential of D. saccifera in vitro cultures for the supply of mainly terpenoid active secondary metabolites and stimulate the continued fractionation of callus EtOAc extract and seedling MeOH to isolate, identify and analyze other possible active substances that may lead to the discovery of new drugs for the treatment of tuberculosis.