NBS bromination reactions of dihydronaphthofuran quinones: a new fragmentation type reaction in the chemistry of quinones

The reactions of isomeric dilydronaphthofuran-quinones of the alfa ß type, 1 and 5, respectively, with NBS, under visible light, gave products. These reactions represent a new route to structural types represented by naphthol [1,2-b] furan and naphtho [2,3-b] furan quinones and lead to a new assessment of biosynthetic theory concerning the furan ring in plants

Seleçäo por meio de células KB de substâncias e extratos potencialmente ativos em quimioterapia do câncer / Selection by means of KB cells of substances and extracts potentially active in cancer chemotherapy

Several synthetic, semi-synthetic and natural compounds as well extracts were screened for their growht inhibition activity on KB cells. The most active ones were naphthoquinones and derivatives of pyrido [4,3-b] carbazole alkaloids, with inhibition dose (ID50) < 4microng/ml. Of the crude extracts of several plants screened, Vellozia caput-ardeae showed to be the most active

Atividade antivirótica de naftoquinonas: II. Derivados 1,4-naftoquinônicos frente a enterovírus

Foram estudadas 15 substâncias de estrutura naftoquinônica obtidas de síntese química: a própria 1,4-naftoquinona sem substituintes, um derivado com um radical hidroxila na posiçäo 2 e 13 derivados hidroxilados apresentando diferentes grupos metileno-amino na posiçäo 3. As culturas de células foram protegidas com as drogas antes da titulaçäo dos vírus (pólio 1, Coxackie B4 e ECHO 19). Pela determinaçäo do índice de inibiçäo virótico (IIV) mostrou-se que o ECHO-vírus 19 foi o mais inibido. Dos 14 compostos testados, 3 deles mostraram um IIV significativo contrao ECHO-vírus como segue: IIV de 1,75 para 2-HO-1,4-naftoquinina e 2-HO-3 (N-morfolil)-metil-1, 4-naftoquinona e IIV de 3,75 para 2-HO-3-N-benzil-N'(N-benzil-2-etilamina) -1,4-naftoquinona. Este último composto mostrou atividade virucida, em experiência paralela, significando que a droga afeta diretamente a partícula viral

Antiviral activity of naphthoquinones: I. Lapachol derivatives against enteroviruses

Some derivatives obtained by chemical transformation of lapachol (a natural substance extracted from the core of plants belonging to the family Bignoniaceae) vere studied as to their posible antiviral action. Cell cultures were treated with those substances and then inoculated with poliovirus type 1, echovirus 19 and Coxsackievirus B type 4. Only ß-lapachone, succinamidyl-ß-norlapachone and intermediary of Hooker have shown a significant viral inhibition index to echovirus type 19. Those derivatives had in in vitro ion but they did not cause any harm to the viral particles studied (virucidal action)