title: Unusual naphthoquinones, catechin and triterpene from Byrsonima microphylla.
abstract: The new triterpene Delta1-lupenone (1), together with lupeol, beta-amyrin and betulin were isolated from the wood of Byrsonima microphylla (Malpighiaceae). The new compounds 3-hydroxy-2-methoxy-8,8,10-trimethyl-8H-antracen-1,4,5-trione (2), 3,7-dihydroxy-2-methoxy-8,8,10-trimethyl-7,8-dihydro-6H-antracen-1,4,5-trione (3), (2S*,10aR*)-2,8-dihydroxy-6-methoxy-1,1,7-trimethyl-2,3,10, 10a-tetrahydro-1H-fenantren-9-one (4) and (2S,3S)-3'-hydroxy-4',5,7-trimethoxy-flavan-3-ol (5) were also isolated through monitored TLC using the antioxidant beta-carotene reagent. The antioxidant potential of the compounds 2-5 was measured and none of them showed activity. The structures of these compounds were elucidated by chemical and spectroscopic analysis based on NMR techniques (1H, 13C NMR, COSY, nOe difference, HMQC and HMBC), UV and MS.
authors.affiliation: Instituto de Química, Universidade Federal da Bahia, Campus de Ondina, 40170290 Salvador (BA), Brazil.
authors.forename: Rosane M
authors.initials: RM
authors.lastname: Aguiar
authors.forename: Juceni P
authors.initials: JP
authors.lastname: David
authors.forename: Jorge M
authors.initials: JM
authors.lastname: David
mesh_terms: D002392:Catechin / Q000737:chemistry / Q000302:isolation & purification*; D005609:Free Radicals / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D029581:Malpighiaceae / Q000737:chemistry*; D015394:Molecular Structure; D009285:Naphthoquinones / Q000737:chemistry / Q000302:isolation & purification*; D018547:Plant Stems / Q000737:chemistry; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D005609:Free Radicals; D009285:Naphthoquinones; D014315:Triterpenes; D002392:Catechin