RESUMO
Three spiro(dipyridinogermole)(dithienogermole) derivatives (1-3), including newly prepared spiro(dipyridinogermole)[di(2-pyridyl)dithienogermole] (3), were examined as photosensitizers for singlet oxygen (1O2) generation in dichloromethane-methanol. Irradiation of their air-saturated solutions led to the generation of 1O2, which was readily trapped by well-known scavengers, dihydronaphthoquinone (DHN) and diphenylisobenzofuran (DPBF). Spiro(dipyridinogermole)[bis(n-hexylbithiophenyl)dithienogermole] (2) showed the best performance with a first-order rate constant that was higher than that of tetraphenylporphyrin (TPP), an efficient photosensitizer for 1O2 generation. This is ascribable to the efficient intersystem crossing characteristic of the dipyridinogermole unit. The quantum yield of 1O2 generation was φΔ = 0.72 for 2, relative to that for rose bengal (RB) in methanol as reference (φΔ = 0.8).
RESUMO
We formulated de novo a poraprezinc-sodium alginate suspension (P-AG) as a specific treatment for severe gingivostomatitis and administered it to 15 patients who had developed such inflammation while on chemotherapy. Very high utility of P-AG was demonstrated and the response was classified as excellent in 10 patients and good in 5 patients. The mechanism of the beneficial effect of P-AG in treatment of severe gingivostomatitis accompanied by hemorrhagic erosion and ulcers is considered to involve the mucosal protective effect, free radical scavenging activity and tissue repair promoting action of poraprezinc together with the hemostatic action of sodium alginate.