RESUMEN
Two new naphthoquinones, 7-hydroxy-2-O-methyldunniol (1) and 7-methoxy-2-O-methyldunniol (2) were isolated from the tubers of Sinningia conspicua (Seem.) G. Nicholson (Gesneriaceae). Nine known compounds were also obtained: 7-methoxydunniol (3), dunniol (4), 7-methoxy-α-dunnione (5), 7-hydroxydunnione (6), 2,4,4',6-tetramethoxychalcone (7), loureirin B (8), allo-calceolarioside A (9), ß-sitosterol (10) and stigmasterol (11). This is the first report of compounds 3 and 5 in Sinningia. n-Hexane, ethyl acetate and ethanol extracts, and compounds 1-5 were tested for cytotoxic activity against PC-3 (prostate) and SKMEL 103 (melanoma) human tumour cell lines and also against the 3T3 (fibroblast) non-cancer cell line. All samples were inactive.
RESUMEN
Three new diterpenoids, demethylfruticuline B (1), 20-hydroxyfruticuline B (2), and 6-hydroxyisofruticuline A (3) were isolated from the leaves of Salvia lachnostachys Benth, together with five known compounds: fruticuline B (4), fruticuline A (5), demethylfruticuline A (6), heterobetulinic acid (7), and maslinic acid (8). The known compounds 7-8 are being reported for the first time in this species. Compounds 1 and 4-6 were tested for antioxidant activity using the ORAC-FL method, and the antioxidant capacity was measured as relative trolox equivalent. All compounds were active, with values of relative trolox equivalent varying between 1.20-2.42. The most active compound was demethylfruticuline B (1).
