Antifungal activity of some 2,2':5',2"-terthiophene derivatives.
The dermatophyte Microsporum cookei Ajello was treated with nine new natural and synthetic 2,2':5',2"-terthiophenes to determine their possible antifungal activity. In the dark the thiophenes were inactive, while when photoactivated with UV-A they induced a remarkable reduction in the growth rate of the fungus. The only exception was (E)-N-(2-methylpropyl)-3-(2,2':5',2"-terthien-5-yl)-propenamide , which was not fungistatic even at the highest dose tested (24 microM). The more active compounds were 3'-methoxy-2,2':5',2"-terthiophene and 3'-methylthio-2,2':5',2"-terthiophene, whose activity seems to be related to the presence of a substituent in the 3' position of the central ring of thiophenes. Transmission electron microscopic observations demonstrated the photoactive nature of the synthetic molecules to be similar to that of alpha-terthienyl, a natural thiophene present in some Asteraceae. The dark treatment caused only the accumulation of the compound in vacuoles, without other evident alterations. After UV-A irradiation the activated thiophene causes severe modifications to the endomembrane system, probably via oxygen-dependent mechanism.
Mares
D
D
Institute of Botany, University of Ferrara, Italy.
Romagnoli
C
C
Rossi
R
R
Carpita
A
A
Ciofalo
M
M
Bruni
A
A
D008027:Light; D008854:Microscopy, Electron; D008864:Microsporum / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development; D013876:Thiophenes / Q000494:pharmacology*
D013876:Thiophenes; C019101:alpha-terthienyl