Applied biological and physicochemical activity of isoquinoline alkaloids: oxoisoaporphine and boldine.

The aim of this study was to determine the electronic influence of substituent groups and annelated rings such as oxazole-oxazinone on the physicochemical and photoprotection, antioxidant capacity, toxicity and singlet oxygen photosensitization biological properties of isoquinoline alkaloid frameworks. Thus, oxoisoaporphine derivatives 1-5 and 3-azaoxoisoaporphine (6), some of them with phenolic structures, did not present any antioxidant capacity, possibly either by formation of keto-enol tautomerism species or the formation of unstable free radicals. Due to the singlet oxygen quantum yields (FD) near to unity, and greater photostability than phenalenone, oxoisoaporphines 4-6 may be considered as photosensitizers for singlet oxygen production and can be used as new universal study tools. The biological application as antibacterial agents is an important and possible tool in the study of compounds with low cytotoxicity and high reactivity in antineoplastic chemotherapy. On the other hand, when boldine and its annelated derivatives B1-4 are irradiated, a photoprotector effect is observed (SPF = 2.35), even after 30 minutes of irradiation. They also act as photoprotectors in cell fibroblast cultures. No hemolysis was detected for boldine hydrochloride and its salts without irradiation. In solutions irradiated before incubation (at concentrations over 200 ppm) photoproducts were toxic to the nauplii of Artemia salina.

Relación estructura-fotoestabilidad u fototoxicidad de fluoroquinolonas / Structure-photostability and phototoxicity relationship in fluoroquinolones

Las quinolonas constituyen una familia de antibióticos de amplio uso en la actualidad, debido a su gran eficacia clínica en el tratamiento de infecciones del tracto respiratorio, urinario, tejidos blandos y enfermedades de transmisión sexual. De acuerdo a su estructura base se pueden clasificar en quinolonas naftiridínicas (enoxacino y ácido nalidíxico), quinolínicas (ciprofloxacino, norfloxacino, ácido oxolínico, rosoxacino) y pirimido-pirimidinicas (ácido pipemídico). Las quinolonas se caracterizan por presentar reacciones de fotosensibilidad y fotolabilidad. El ácido nalidíxico, quinolona de primera generación, presenta reacciones de fototoxicidad, evaluadas en el modelo del glóbulo rojo y en cultivos celulares. El ácido nalidíxico, exento del sustituyente piperazínico presenta una fotolabilidad disminuida. Las fluoroquinolonas, a diferencia del ácido nalidíxico, presentan un anillo piperazínico o metil piperazínico en posición 7, incorporado con el fin de mejorar las propiedades antibacterianas. En este trabajo se investiga la influencia del anillo piperazínico en posición 7 sobre la fotolabilidad y fototoxicidad, demostrándose que las fluoroquinolonas que poseen este sustituyente presentan una fotolabilidad aumentada y una fototoxicidad disminuída, en relación a quinolonas carentes de éste grupo. Es probable que la fotodegradación de quinolonas transcurra mediante un mecanismo radicalario, con la pérdida del grupo carboxílico

Quinolones constitute a large class of synthetic antimicrobial agents that are highly effective in the treatment of respiratory, urinary, sexually transmitted diseases and soft tissue infection. In agreement with his structure the quinolones can be classified into naftaridines (enoxacin and nalidixic acid), quinolines (ciprofloxacin, norfloxacin, oxolinic acid, roxosacin) and pyrid-pyrimidin (pipemidic acid). Some quinolones may undergo photodegradation reactions. On the other hand, quinolones can induce cutaneous photosensitivity reactions.and photolability as well. Nalidixic acid, a first quinolone generation, may undergo phototoxic effects on the red blood cells and in cell culture. Nalidixic acid, which has not the piperazine group in position 7, exhibit a moderated photolability. The fluoroquinolones as oppossed to nalidixic acid have a piperazine ring in position 7. We investigated the influence of the piperazine ring on the phototoxicity and photolability of several quinolones. We demonstrated that the fluoroquinolones with piperazinic group present higher photolability and less phototoxicity .It is possible that the photodegradation of quinolones takes place through a radical pathway, with the loss of a carboxylic acid group