Simões, Maria de FátimaRijo, PatríciaDuarte, AidaMatias, DiogoRodríguez, Benjamín2011-08-222011-08-222010Phytochemistry Letters. December 2010, 3(4) 234-2371874-3900http://dx.doi.org/10.1016/j.phytol.2010.09.001http://hdl.handle.net/10451/3935Parvifloron D was isolated from Plectranthus ecklonii together with sugiol and mixtures of β-sitosterol and stigmasterol and ursolic and oleanolic acids. Treatment of parvifloron D [2α-(4-hydroxy)benzoyloxy-11-hydroxy-5,7,9(11),13-abietatetraen-12-one] with acid-washed molecular sieves gave the microstegiol derivative 2β-(4-hydroxy)benzoyloxy-11β-hydroxy-4(5 → 11),20(10 → 5)diabeo-5(10),6,8,13-abietatetraen-12-one in a moderate yield (26%). The new microstegiol derivative inhibited the growth of some Staphylococcus and Enterococcus species with significant MIC values ranging from 3.91 to 7.81 μg/ml.engPlectranthus eckloniiLabiataeAbietanesRearranged abietanesMicrostegiol derivativeAcid-washed molecular sieves as catalystjournal article