The present study shows for the first time the phenolic composition and the in vitro properties (antioxidant and inhibition of nitric oxide production) of Hypericum calabricum Sprengel collected in Italy. The content of hypericins (hypericin and pseudohypericin), hyperforin, flavonoids (rutin, hyperoside, isoquercetrin, quercitrin, quercetin and biapigenin) and chlorogenic acid of H. calabricum, have been determined. The ethyl acetate fraction from the aerial parts of H. calabricum exhibited activity against the radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) with IC50 value of 1.6 jig/ml. The test for inhibition of nitric oxide (NO) production was performed using the murine monocytic macrophage cell line RAW 264.7. The ethyl acetate fraction had significant activity with an IC50 value of 102 jig/ml and this might indicate that it would have an anti-inflammatory effect in vivo.

Dois tetranortriterpenos, sendo um inédito e dois novos derivados do acido dihidrocinâmico foram obtidos da madeira de Hortia colombiana. Suas estruturas foram elucidadas por RMN, e as configurações relativas estabelecidas através de experimentos de nOe diferencial. Em adição, foram isolados aloxantoxiletina, nerolidol, epoxinerolidol, três conhecidos derivados do acido dihidrocinâmico e duas amidas.

A novel tetranortriterpenoid and two dihydrocinnamic acid derivatives were obtained from the wood of Hortia colombiana. Their structures were elucidated by detailed NMR investigations and the relative configurations established by Difference NOE experiments. In addition, alloxanthoxyletin, nerolidol, epoxynerolidol, three known dihydrocinnamic acid derivatives and two amides were isolated. Detailed analysis of NMR data of Hortiolide A, whose structure was previosly established by X ray, are also provided.