title: Flavonoids from Lonchocarpus muehlbergianus.
abstract: The light petroleum extract from the roots of Lonchocarpus muehlbergianus Hassl contained nine flavonoids, including six new ones. These are 2,4-cis-2,4,5,8-tetramethoxy-(2'',3'':6,7)-furanoflavan; 2,4-cis-4-hydroxy-2,5,8-trimethoxy-(2'',3'':6,7)-furanoflavan; 2,4-cis-2-prenyloxy-4,5,8-trimethoxy-(2'',3'':6,7)-furanoflavan; 2,4-cis-2-prenyloxy-4-hydroxy-5,8-dimethoxy-(2'',3'':6,7)-furanoflavan; 2',5',6'-trimethoxy-9-(1,1-dimethylallyoxy)-[2'',3'':3',4']-furanochalcone; 5,6-dimethoxy-(2'',3'':7,8)-furanoflavone, identified by analysis of their spectral data (UV, IR, 1H and 13C NMR, 2D-NMR, NOE and MS). The natural occurrence of 2,4-dioxygenated flavan derivatives is being reported for the first time. Quantitative analysis of the petrol extract, by using reversed-phase HPLC, showed that the most abundant flavonoid in the extract is 2,4-cis-2,4,5,8- tetramethoxy-(2'',3'':6,7)-furanoflavan.
authors.affiliation: Departamento de Química Orgânica, Instituto de Química, UNICAMP, Cx. Postal 6109, 13083-970 Campinas, SP, Brazil. aderbal@iqm.unicamp.br
authors.forename: Aderbal F
authors.initials: AF
authors.lastname: Magalhães
authors.forename: Ana M G A
authors.initials: AM
authors.lastname: Tozzi
authors.forename: Eva G
authors.initials: EG
authors.lastname: Magalhães
authors.forename: Ivani S
authors.initials: IS
authors.lastname: Blanco
authors.forename: Maria-del-Pilar C
authors.initials: MD
authors.lastname: Soriano
mesh_terms: D007887:Fabaceae / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification*; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry
chemical_list: D005419:Flavonoids; D010936:Plant Extracts