Determination and applications of the molar absorptivity of phenolic adducts with captopril and mesna.
Captopril and mesna are molecules with a free thiol group, used as active ingredients due to their hypotensor and mucolytic properties, respectively. These compounds cross the hematoencephalic barrier and, due to the reactivity of their thiol group, can form adducts with the o-quinones formed during the oxidation of mono- and o-diphenols. Polyphenol oxidase from plants and fungi can be used as a tool for generating o-quinones in their action on o-diphenols and facilitate the formation of adducts in the presence of captopril or mesna. The spectrophotometric characterization of these adducts is useful from several points of view. Here, using the end-point method, which involves the exhaustion of oxygen in the medium, we determined the molar absorptivity of the adducts of different o-diphenols with captopril and mesna. Besides the analytical interest of this approach, we also use it to make a kinetic characterization of polyphenol oxidase as it acts on o-diphenolic substrates that produce unstable o-quinones.
García-Molina
F
F
GENZ, Grupo de Investigación de Enzimología, Departamento de Bioquímica y Biología Molecular-A, Facultad de Biología, Universidad de Murcia, A. Correos 4021, E-30080 Murcia, Spain.
Muñoz-Muñoz
J L
JL
García-Molina
M
M
Molina-Alarcon
M
M
García-Ruíz
P A
PA
Tudela
J
J
Rodríguez-López
J N
JN
D002216:Captopril / Q000737:chemistry*; D004156:Catechol Oxidase / Q000378:metabolism; D005419:Flavonoids / Q000737:chemistry / Q000378:metabolism; D015080:Mesna / Q000737:chemistry*; D018377:Neurotransmitter Agents / Q000737:chemistry; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry* / Q000378:metabolism; D059808:Polyphenols; D011809:Quinones / Q000737:chemistry; D013053:Spectrophotometry; D013438:Sulfhydryl Compounds / Q000737:chemistry
D005419:Flavonoids; D018377:Neurotransmitter Agents; D010636:Phenols; D059808:Polyphenols; D011809:Quinones; D013438:Sulfhydryl Compounds; D002216:Captopril; D004156:Catechol Oxidase; D015080:Mesna