Additional flavonoids from Lonchocarpus yucatanensis and L-xuul

Two new natural flavanones, 5 -hydroxy-6,7-(2",2"-dimethylcliromene)flavan one (1) and 5-methoxy-3-hydroxy-6,7-(2",2"-dimethylchromene)flavanone (2), were isolated from the root extracts of L. yucatanensis and L xuul, respectively. Additionally, four known metabolites, the glycosidic flavonoids quercetin-3-rhamnoglucoside and kaempferol-3-rhamnoglucoside, together with 4hydroxy-N-methyl- pro line, and p-coumaric acid methyl ester, were isolated for the first time from the leaves of L. xuul. The various metabolites were identified on the basis of their spectroscopic data and by comparison with those reported in the literature.