AUTHOR=Tang Chenghao , Guo Wenbo , Yang Shengzhou , Hu Xiuhong , Chen Xingju , Wang Xiang 

TITLE=Design, synthesis and antifungal activity of novel 1,4-benzoxazin-3-one derivatives containing an acylhydrazone moiety

JOURNAL=Frontiers in Chemistry

VOLUME=11

YEAR=2023

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2023.1233443

DOI=10.3389/fchem.2023.1233443

ISSN=2296-2646

ABSTRACT=<p>A series of 1,4-benzoxazin-3-one derivatives containing an acylhydrazone moiety were designed, synthesized and evaluated for their <italic>in vitro</italic> antifungal activities against <italic>Gibberella zeae</italic>, <italic>Pellicularia sasakii</italic>, <italic>Phytophthora infestans</italic>, <italic>Capsicum wilt</italic>, and <italic>Phytophthora capsica</italic>. The structures of target compounds were characterized by <sup>1</sup>H NMR, <sup>13</sup>H NMR, <sup>19</sup>F NMR and HRMS. The preliminary antifungal evaluation of all target compounds showed that some target compounds possessed moderate to good activities against <italic>G. zeae</italic>, <italic>P. sasakii</italic>, <italic>P. infestans</italic> and <italic>C. wilt</italic>. Among them, compounds <bold>5L</bold> and <bold>5o</bold> exhibited noticeable inhibition effects against <italic>G. zeae</italic> with the EC<sub>50</sub> values (effective concentration for 50% activity) of 20.06 and 23.17 <italic>μ</italic>g/ml, respectively, which were even nearly double effective than that of hymexazol (40.51 <italic>μ</italic>g/ml). Meanwhile, compound <bold>5q</bold> displayed a notable inhibitory effect toward <italic>P. sasakii</italic>, with the EC<sub>50</sub> value of 26.66 μg/ml, which was better than that of hymexazol (32.77 <italic>μ</italic>g/ml). In addition, compound <bold>5r</bold> yielded the EC<sub>50</sub> value of 15.37 <italic>μ</italic>g/ml against <italic>P. infestans</italic>, which was less than those of hymexazol (18.35 <italic>μ</italic>g/ml) and carbendazim (34.41 <italic>μ</italic>g/ml). Eventually, compound <bold>5p</bold> showed higher inhibitory effect against <italic>C. wilt</italic>, with EC<sub>50</sub> value of 26.76 <italic>μ</italic>g/ml, which was better than that of hymexazol (&gt;50 <italic>μ</italic>g/ml).</p>