Plumbagin is a naturally occurring naphthoquinone isolated from roots of Plumbago scandens. The plant was collected at the Campus of Fundação Oswaldo Cruz, Rio de Janeiro, Brazil. P. scandens is used as a traditional medicine for the treatment of several diseases. The antimicrobial activity of plumbagin was evaluated using the macrodilution method. The compound exhibited relatively specific act...

Two compounds recognized as responsible for the insecticidal activity of extracts of Calceolaria andina L. (Scrophulariaceae) have been isolated and characterized as 2-(1, 1-dimethylprop-2-enyl)-3-hydroxy-1,4-naphthoquinone and the corresponding acetate, 2-acetoxy-3-(1,1-dimethylprop-2-enyl)-1, 4-naphthoquinone. Their activities against 29 pest species and 9 beneficial species of arthropod from...

SUMMARY We have prepared an antibody against 1,2-naphthoquinone. This was accomplished by conjugating the quinone to bovine gamma-globulin. The conjugation product showed a visible light absorption peak of 445 m/u. The globulin-quinone antigen was used to produce rabbit antibodies shown to be specific for 1,2-naphthoquinone. The antibodies could be demonstrated by tanned cell hemagglutination a...

treatment of 5,8-dihydroxy-1-tetralone (9) with either 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (ddq) in refluxing benzene or silver (i) oxide in refluxing 1,4-dioxane afforded juglone (5-hydroxy-1,4-naphthoquinone) (1) in good yield. with manganese dioxide in dioxane the tetralone gave a mixture of juglone and naphthazarin (5,8-dihydroxy-1,4-naphthoquinone) (3), the proportion of naphthazarin...

INTRODUCTION Naphthoquinone derivatives are under investigation as potential therapeutic agents. The antibacterial and antifungal activity of lawsone and of some novel naphthoquinone derivatives was assessed in vitro. METHODS The antimicrobial activity was determined using diffusion disk and the broth microdilution methods against seven bacteria and three Candida species, according to recomme...

A variety of organocatalysts were screened for the catalysis of the naphthoquinone monoketal Diels-Alder reaction. In this study we found that Schreiner's thiourea catalyst 10 and Jacobson's thiourea catalyst 12 facilitate the cycloaddition of the sterically hindered naphthoquinone monoketal dienophile 3 with diene 4. The use of thiourea catalysis allowed for the first time the highly selective...

Treatment of 5,8-dihydroxy-1-tetralone (9) with either 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in refluxing benzene or silver (I) oxide in refluxing 1,4-dioxane afforded juglone (5-hydroxy-1,4-naphthoquinone) (1) in good yield. With manganese dioxide in dioxane the tetralone gave a mixture of juglone and naphthazarin (5,8-dihydroxy-1,4-naphthoquinone) (3), the proportion of naphthazarin...

A series of 3-substituted-2-hydroxy-1,4-naphthoquinone derivatives with a variety side chains were successfully synthesized by Mannich reaction 2-hydroxy-1,4-naphthoquinone (lawsone) selected amines and aldehydes. All substances (1–16) evaluated for in-vitro antimalarial activity against strains Plasmodium falciparum microculture radioisotope technique. Bioassay data revealed that ten (1–8, 11 ...