International Journal of Diseases and Disorders

ISSN 2329-9835

International Journal of Diseases and Disorders ISSN 2329-9835 Vol. 3 (7), pp. 001-007, July, 2015. © International Scholars Journals

Full Length Research Paper

The preliminary study of inhibitory mechanism of sulfone compounds xa202 and xt208 against Gibberella zeae

Linhong Jin, Jiang He, Ming He, Weiming Xu and Song Yang*

State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang, 550025, Guizhou Province, P. R. China.

Accepted 07 April, 2015

Abstract 

A series of novel methyl sulfone derivatives containing 1,3,4-oxadiazole (thiadiazole) moiety were bioassayed in vitro against Gibberella zeae using mycelial growth rate method. The bioassay results showed that compounds xa202 and xt208 displayed excellent antifungal activity against G. zeae with EC50 values of 3.49 μg/ml and 3.73 μg/ml, respectively. The mechanism for compounds xa202 and xt208 against G. zeae were studied. After treating with compounds xa202 and xt208 at 50 μg/ml for 24 h, the permeability of fungi cell membranes, the conductivity and the concentration of calcium ions (Ca2+) in mycelial solution showed increasing tendency, while the chitinase content experienced a slight decline initially and then increased rapidly. Compounds xa202 and xt208 were also found to have more potent inhibitory activities against ergosterol biosynthesis than a commercial fungicide, carbendazol. The inhibitory rates for xa202 and xt208 were 32.04% and 55.34%, respectively.

Key words: Gibberella zeae, mechanism of action, conductivity, calcium ions and ergosterol biosynthesis.