RESUMO
Chemical investigation of the n-hexane and EtOAc fractions of the ethanolic extract from Styrax pohlii (Styracaceae) aerial parts resulted in the isolation of the benzofuran nor-neolignan derivatives egonol (1), homoegonol (2), homoegonol gentiobioside (3), homoegonol glucoside (4) and egonol gentiobioside (5). This is the first report of compounds 1-5 in S. pohlii. Compounds 1-5, the acetyl derivatives 1 a and 2 a, the ethanolic extract (EE), the n-hexane fraction (HF) and EtOAc fraction (EF) were tested for their inhibitory activities against COX-1 and COX-2. The results showed that EE, HF, EF and compounds 1-5 and 1 a-2 a shown weak to moderate inhibition of COX-1 and COX-2. Among the assayed nor-neolignans, 4 gave a COX-1 inhibition of 35.7% at 30 µM. Compound 5 displayed a COX-2 inhibition of 19.7% at 30 µM.
Assuntos
Inibidores de Ciclo-Oxigenase/farmacologia , Lignanas/farmacologia , Extratos Vegetais/farmacologia , Styrax/química , Benzofuranos/isolamento & purificação , Benzofuranos/farmacologia , Brasil , Inibidores de Ciclo-Oxigenase/química , Inibidores de Ciclo-Oxigenase/isolamento & purificação , Dissacarídeos/isolamento & purificação , Dissacarídeos/farmacologia , Etanol , Glucosídeos/isolamento & purificação , Glucosídeos/farmacologia , Hexanos , Lignanas/química , Lignanas/isolamento & purificação , Estrutura Molecular , Extratos Vegetais/isolamento & purificaçãoRESUMO
Styrax camporum Pohl, known in Brazil as 'estoraque do campo' or 'cuia de brejo', has been used in the treatment of gastrointestinal diseases. The therapeutic action of S. camporum has been attributed to the ethyl acetate fraction, although the chemical composition of this fraction has not yet been analyzed. In this study, a high-performance liquid chromatography photodiode array detection (HPLC-PAD) method for analysis of Brazilian Styrax species has been developed. The compounds egonol (1) and homoegonol (2) were found to be present in all the samples investigated by HPLC. These compounds were isolated by open column chromatography followed by preparative TLC, and were identified by ¹H NMR. Compounds 1 and 2 were thus proposed as phytochemical markers for Styrax, owing to their biological properties and presence in other Styrax species. The developed method has been validated and successfully applied for quantification of 1 and 2 in S. camporum dried leaves and crude ethanolic extracts from S. ferrugineus and S. pohlii aerial parts.