Light-induced full aromatization and hydroxylation of 7-methoxy-1-methyl-3,4-dihydro-2H-pyrido[3,4-b]indole alkaloid: Oxygen partial pressure as a key modulator of the photoproducts distribution.
Villarruel, F., Denofrio, M. P., Rasse-Suriani, F. A. O., Garcia Einschlag, F. S., Schmidt De Leon, T., Erra-Balsells, R. and Cabrerizo, F. M.
Light-induced full aromatization and hydroxylation of 7-methoxy-1-methyl-3,4-dihydro-2H-pyrido[3,4-b]indole alkaloid: Oxygen partial pressure as a key modulator of the photoproducts distribution.
Author Address:
Instituto Tecnologico de Chascomus (INTECH), Universidad Nacional de San Martin (UNSAM), Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Av. Intendente Marino Km 8.2, CC 164, B7130IWA Chascomus, Argentina; Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), CCT-La Plata, Universidad Nacional de La Plata, Diag. 113 y 64, 1900 La Plata, Argentina.
Instituto Tecnologico de Chascomus (INTECH), Universidad Nacional de San Martin (UNSAM), Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Av. Intendente Marino Km 8.2, CC 164, B7130IWA Chascomus, Argentina.
Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), CCT-La Plata, Universidad Nacional de La Plata, Diag. 113 y 64, 1900 La Plata, Argentina.
Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Quimica Organica, Pabellon II, 3er P., Ciudad Universitaria, 1428 Buenos Aires, Argentina; CONICET, Universidad de Buenos Aires, Centro de Investigacion en Hidratos de Carbono (CIHIDECAR), Facultad de Ciencias Exactas y Naturales, Pabellon II, 3er P., Ciudad Universitaria, 1428 Buenos Aires, Argentina.
Instituto Tecnologico de Chascomus (INTECH), Universidad Nacional de San Martin (UNSAM), Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Av. Intendente Marino Km 8.2, CC 164, B7130IWA Chascomus, Argentina. Electronic address: fcabrerizo@intech.gov.ar.
Full-aromatic and partially hydrogenated beta-carboline (betaC) derivatives constitute a group of alkaloids widely distributed in a great variety of living systems. In plants and bacteria, tetrahydro-betaCs are the primary product of the Pictet-Spengler enzymatically catalyzed condensation. Tetrahydro-betaC skeleton is further modified giving rise to the formation of a vast set of derivatives including dihydro- and full-aromatic betaCs. However, in most of the cases, the later processes still remain unclear and other sources, such as photo-triggered reactions, deserve to be explored. In this context, the photophysic and photochemistry of 7-methoxy-1-methyl-3,4-dihydro-2H-pyrido[3,4-b]indole or harmaline (Hlina) in aqueous solution is reported herein. UV-visible absorption and fluorescence emission spectroscopy coupled with multivariate data analysis (PARAFAC), HPLC and HRESI-MS techniques were used for both quantitative and qualitative analysis. The formation singlet oxygen and hydrogen peroxide reactive oxygen species (ROS) was quantified and their role together with the influence of pH and oxygen partial pressure on the photochemical degradation of HlinaH(+) was assessed. We report herein the first study on photochemical full-aromatization of a dihydro-betaC derivative. These results can shed some light on the betaCs biosynthesis and role in living systems.
Journal of Photochemistry and Photobiology. B: Biology 199: 111600 (2019)