RÉSUMÉ
The biosynthetic pigment from Chromobacterium violaceum BB-78, 1,3-dihydro-2H-indol-2-one and its derivatives exhibit biological activities such as antimicrobial action, low hemolytic effects on red blood cells and in vitro trypanocide activity. A relatively high cytotoxicity on V-79 hamster fibroblast cells of the biosynthetic pigment was found, although with the methylol derivative the toxicity was almost eliminated. The methylol derivative exhibited similar toxicity as Nifurtimox, a known, commercial trypanocide compound
Sujet(s)
Animaux , Cricetinae , Antibactériens/toxicité , Chromobacterium/métabolisme , Hémolyse , Indoles/toxicité , Pigments biologiques/toxicité , Antibactériens/isolement et purification , Bactéries/effets des médicaments et des substances chimiques , Lignée cellulaire , Survie cellulaire/effets des médicaments et des substances chimiques , Chromobacterium/croissance et développement , Fibroblastes/effets des médicaments et des substances chimiques , Indoles/isolement et purification , Tests de sensibilité microbienne , Nifurtimox/toxicité , Pigments biologiques/isolement et purification , Trypanosoma cruzi/effets des médicaments et des substances chimiques , Trypanosoma cruzi/croissance et développementRÉSUMÉ
1. Chromobacterium violaceum (strain BB-78 isolated in Brazil) produces violacein, a substance potentially useful in phototherapy and with antibiotic and trypanocide activity. Culture conditions were optimized for the production of violacein and change in nutrients, temperature and pØ were correlated to cellular growth. 2. Methionine was the only absolute requirement for growth. alanine, arginine, tryptophan and vitamin B12 and its metabolites were important as a carbon source for violacein production and bacterial growth. 3. The highest yields of violacein were obtained by incubation in liquid medium and in the obsence of light at pH 7.0 and 28-C for 24 h