Total NMR assignments of new [C7-O-C7'']-biflavones from leaves of the limonene-carvone chemotype of Lippia alba (Mill) N. E. Brown.
Phytochemical analysis of leaves of the limonene-carvone chemotype of Lippia alba led to the isolation of two biflavonoids with a new structural pattern with an ether linkage: 5,5''-dihydroxy-6,4',6'',3''',4'''-pentamethoxy-[C(7)--O--C(7'')]-biflavone (1) and 4',4,5,5''-tetrahydroxy-6,6'',3'''-trimethoxy-[C(7)--O--C(7'')]-biflavone (2). Structural elucidation of the new compounds was established on the basis of spectral data, through the use of 1D NMR and several 2D shift correlated NMR pulse sequences (COSY, HMQC, HMBC and NOESY).
Barbosa
Francisco Geraldo
FG
Curso de Pós-Graduação em Química Orgânica, Departamento de Química Orgânica e Inorgânica, Centro de Ciências, Universidade Federal do Ceará, CP 12 200, 60451-970 Fortaleza, CE, Brazil.
Lima
Mary Anne Sousa
MA
Silveira
Edilberto Rocha
ER
D044946:Biflavonoids / Q000737:chemistry* / Q000302:isolation & purification; D000081005:Cyclohexane Monoterpenes; D053138:Cyclohexenes; D000077222:Limonene; D032411:Lippia / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods* / Q000592:standards; D015394:Molecular Structure; D039821:Monoterpenes / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D012015:Reference Standards; D013729:Terpenes / Q000737:chemistry*
D044946:Biflavonoids; D000081005:Cyclohexane Monoterpenes; D053138:Cyclohexenes; D039821:Monoterpenes; D013729:Terpenes; C006923:carvone; D000077222:Limonene