AUTHOR=Fu Xiaoxiang , Xiao Suling , Cao Duantao , Yuan Minxuan , Xiang Miaolian , Zhou Qinghong , Huang Yingjin , Wei Hongyi , Peng Wenwen 

TITLE=Antifungal active ingredient from the twigs and leaves of Clausena lansium Lour. Skeels (Rutaceae)

JOURNAL=Frontiers in Chemistry

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2022.1104805

DOI=10.3389/fchem.2022.1104805

ISSN=2296-2646

ABSTRACT=<p>Two novel amides, named clauphenamides A and B, and twelve other known compounds were isolated from the twigs and leaves of <italic>Clausena lansium</italic> Lour. Skeels (Rutaceae). Their structures were elucidated on the basis of extensive spectroscopic analysis and comparison with data reported in the literature. Clauphenamide A (<bold>1</bold>) featured in the unit of N-2-(4,8-dimethoxyfuro [2,3-b]quinolin-7-yl)vinyl, and clauphenamide B (<bold>2</bold>) was a unprecedented N-phenethyl cinnamide dimer. Other known compounds belong to pyrrolidone amides (<bold>3</bold> and <bold>4</bold>), furacoumarins (<bold>7</bold>–<bold>10</bold>), simple coumarins (<bold>11</bold>–<bold>14</bold>), lignan (<bold>5</bold>) and sesquiterpene (<bold>6</bold>). Compounds <bold>5</bold>, <bold>6</bold>, <bold>10</bold> and <bold>12</bold> were separated from the genus (<italic>Clausena</italic>) for the first time, while <bold>13</bold> was isolated in the species (<italic>C. lansium</italic>) for the first time. The antifungal activities of the isolated compounds were assayed. As a result, at the concentration of 100 <italic>μ</italic>g/ml, compared with the control (chlorothalonil, inhibition rate of 83.67%), compounds <bold>1</bold> and <bold>2</bold> were found to exhibit moderate antifungal activity against <italic>B. dothidea</italic> with inhibition rates of 68.39% and 52.05%, respectively. Compounds <bold>11</bold>–<bold>14</bold> also exhibited moderate activity against <italic>B. dothidea</italic> and <italic>F. oxysporum</italic>, with inhibition rates greater than 40%. In addition, compared with the control (chlorothalonil, inhibition rate of 69.02%), compounds <bold>11</bold>–<bold>14</bold> showed strong antifungal activity to <italic>P. oryzae</italic>, with inhibition rates greater than 55%. Among them, compound <bold>14</bold> has the strongest antifungal activity against <italic>P. oryzae</italic>, and the inhibition rate (65.44%) is close to that of the control chlorothalonil. Additionally, the structure-activity relationships of the separated compounds are also discussed preliminarily in this paper.</p>