Development of new fungicides against Magnaporthe grisea: synthesis and biological activity of pyrazolo[3,4-d][1,3]thiazine, pyrazolo[1,5-c][1,3,5]thiadiazine, and pyrazolo[3,4-d]pyrimidine derivatives.
Some pyrazolo[3,4-d]pyrimidin-4(5H)-thione, pyrazolo[3,4-d][1,3]thiazin-4-one/thione, and pyrazolo[1,5-c][1,3,5]thiadiazine-4-one/thione derivatives were synthesized and screened for antifungal activity against the causal agent of rice blast disease, Magnaporthe grisea. In all cases a remarkable inhibition of fungal growth was found in the range from 10 to 200 microg x mL(-1). Several compounds were able to control mycelium growth at a rate of 10 microg x mL(-1), a concentration at which the reference compound tricyclazole was completely ineffective. At least in the case of the most active substance, at the same dose the growth of seedlings or cultured cells of rice was substantially unaffected. Results allowed definition of structural requirements either to maintain or to enhance mycotoxic activity.
Vicentini
Chiara B
CB
Dipartimento di Scienze Farmaceutiche, Università di Ferrara, I-44100 Ferrara, Italy. vcc@unife.it
Forlani
Giuseppe
G
Manfrini
Maurizio
M
Romagnoli
Carlo
C
Mares
Donatella
D
D005659:Fungicides, Industrial / Q000138:chemical synthesis* / Q000494:pharmacology*; D020082:Magnaporthe / Q000187:drug effects* / Q000254:growth & development*; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D011743:Pyrimidines / Q000737:chemistry; D013829:Thiadiazines / Q000138:chemical synthesis / Q000494:pharmacology; D013843:Thiazines / Q000138:chemical synthesis / Q000494:pharmacology
D005659:Fungicides, Industrial; D011720:Pyrazoles; D011743:Pyrimidines; D013829:Thiadiazines; D013843:Thiazines; C014175:pyrazolo(3,4-d)pyrimidine