title: Calmodulin inhibitors from Leucophyllum ambiguum.
abstract: Activity-directed fractionation of a CH(2)Cl(2)-MeOH (1:1) extract of Leucophyllum ambiguum led to the isolation of two new lignans designated with the trivial names of 2'-methoxykobusin (1) and 2'-methoxy-4' '-hydroxydemethoxykobusin (2). In addition, the known compounds kobusin (3), 2',2' '-dimethoxysesamin (4), trans-cinnamic acid, apigenin, and apigetrin were obtained. The identification of the novel analogues 1 and 2 was accomplished by spectral methods. The structure of 1 was unequivocally confirmed by X-ray analysis. Compounds 1-4 interacted with bovine-brain calmodulin and inhibited the activation of the calmodulin-dependent enzyme cAMP phosphodiesterase.
authors.affiliation: Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, D.F. 04510, México.
authors.forename: Susana
authors.initials: S
authors.lastname: Rojas
authors.forename: Laura
authors.initials: L
authors.lastname: Acevedo
authors.forename: Martha
authors.initials: M
authors.lastname: Macías
authors.forename: Rubén A
authors.initials: RA
authors.lastname: Toscano
authors.forename: Robert
authors.initials: R
authors.lastname: Bye
authors.forename: Barbara
authors.initials: B
authors.lastname: Timmermann
authors.forename: Rachel
authors.initials: R
authors.lastname: Mata
mesh_terms: D000818:Animals; D047310:Apigenin; D001921:Brain / Q000201:enzymology; D002147:Calmodulin / Q000037:antagonists & inhibitors*; D002417:Cattle; D002934:Cinnamates / Q000737:chemistry / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification; D006023:Glycoproteins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D017705:Lignans / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D008800:Mexico; D015394:Molecular Structure; D010946:Plants, Medicinal / Q000737:chemistry*; D028083:Scrophulariaceae / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D002147:Calmodulin; D002934:Cinnamates; D005419:Flavonoids; D006023:Glycoproteins; D017705:Lignans; C029010:cinnamic acid; C057792:apigetrin; D047310:Apigenin