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Novel 4‐pyrazole carboxamide derivatives containing flexible chain motif: design, synthesis and antifungal activity
Author(s) -
Liu XingHai,
Qiao Li,
Zhai ZhiWen,
Cai PengPeng,
Cantrell Charles L,
Tan ChenXia,
Weng JianQuan,
Han Liang,
Wu HongKe
Publication year - 2019
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/ps.5463
Subject(s) - phytophthora capsici , sclerotinia sclerotiorum , botrytis cinerea , fungicide , pyrazole , rhizoctonia solani , sclerotinia , fusarium oxysporum , cercospora , alternaria solani , carboxamide , gibberella zeae , chemistry , stereochemistry , biology , phytophthora , fusarium , horticulture , leaf spot
Background In recent years, carboxamide fungicides, targeting succinate dehydrogenase (SDH), have shown highly efficient and broad spectrum fungicidal activity. Structure–activity relationship (SAR) results for these commercial fungicides show that the carboxamide group was a key active group. This is useful information for the discovery of new pyrazole carboxamide derivatives with fungicidal activity. Results Twenty‐seven novel pyrazole carboxamides were designed and synthesized. Their fungicidal activities against Gibberella zeae , Phytophthora infestans , Phytophthora capsici , Rhizoctonia solani , Alternaria solani , Botrytis cinerea , Fusarium oxysporum , Cercospora arachidicola , Sclerotinia sclerotiorum and Physalospora piricola were tested; derivatives possessed excellent inhibitory at 50 mg L −1 in particular. Furthermore, some pyrazole carboxamides exhibited remarkably high activities against Sclerotinia sclerotiorum in vitro with EC 50 values of 2.04 to 15.2 μg mL −1 . In addition, some compounds also exhibited high activities against Physalospora piricola , Cercospora arachidicola and Phytophthora capsici . Inhibition activities against SDH proved that the designed analogues were effective at the enzyme level. The SAR of these pyrazole carboxamides was studied by using the docking method. Conclusion It is possible that pyrazole carboxamides, which exhibit good activity against Sclerotinia sclerotiorum , can be further optimized as a lead compounds of carboxamide fungicides. © 2019 Society of Chemical Industry