Chemical constituents from Sidastrum paniculatum and evaluation of their leishmanicidal activity

Sidastrum paniculatum (L.) Fryxell, Malvaceae, is popularly known in Brazil as “malva-roxa” or “malvavisco”. The species is found mainly in Northeast region where it is used by locals to treat spider bites and bee stings. Aiming to identify the chemical compounds from S. paniculatum secondary metabolism and to contribute to the chemotaxonomic knowledge of Malvaceae family, a phytochemical study of S. paniculatum was carried out. Besides that, the isolated compounds were evaluated for antileishmanial activity against promastigotes of Leishmania braziliensis. By using chromatographic techniques the study resulted the isolation of eight compounds: 3-oxo-21β-H-hop-22(29)-ene; sebiferic acid; sitosterol 3-O-β-d-glucopyranoside/stigmasterol 3-O-β-d-glucopyranoside; phaeophytin a; 132(S)-hydroxyphaeophytin a; 132(S)-hydroxy-(173)-ethoxyphaeophorbide a and 7,4′-di-O-methylisoescutellarein. The structure of all isolated compounds was elucidated by spectroscopic analysis, including two-dimensional NMR techniques. In addition, the isolated compounds phaeophytin a; 132(S)-hydroxyphaeophytin a; 132(S)-hydroxy-(173)-ethoxyphaeophorbide a and 7,4′-di-O-methylisoescutellarein exhibited antileishmanial activity against promastigotes of L. braziliensis.