In the current work, we synthesized two series of dehydroabietyl amide derivatives from natural product rosin and evaluated their antifungal effects on Valsa mali, Phytophthora capsici, Botrytis cinerea, Sclerotinia sclerotiorum, and Fusarium oxysporum. In vitro and in vivo antifungal activities results indicated that rosin-based amide compounds containing thiophene heterocycles had better inhibitory effects on B. cinerea. In particular, compound 5b (5-fluoro-2-thiophene dehydroabietyl amide) exhibited the excellent antifungal properties against B. cinerea with an EC₅₀ of 0.490 mg/L, which was lower compared to the positive control penthiopyrad (0.562 mg/L). Physiological and biochemical studies showed that the primary action mechanism of compound 5b on B. cinerea changes mycelial morphology, increases cell membrane permeability, and inhibits the TCA pathway in respiratory metabolism. Furthermore, QSAR and SAR studies revealed that charge distribution of rosin-based amides derivatives have a key role in the antifungal activity through the hydrogen bonding, conjugation, and electrostatic interaction between the compounds and the receptors of the target. To sum up, this study contributes to the development of rosin-based antifungal agents with a novel structure and preferable biological activity.

中文翻译：

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可再生松树树脂松香衍生物在农作物保护中的抗真菌应用

在当前的工作中，我们从天然产物松香中合成了两个系列的脱氢松香酰胺衍生物，并评估了它们对Valsa mali，Phytophthora capsici，Botrytis cinerea，Sclerotiania sclerotiorum和Fusarium oxysporum的抗真菌作用。体外和体内抗真菌活性结果表明，含噻吩杂环的松香基酰胺化合物对灰葡萄孢的抑制作用更好。尤其是，化合物5b（5-氟-2-噻吩脱氢松香基酰胺）对EC的灰葡萄孢表现出优异的抗真菌性能。₅₀为0.490 mg / L，低于阳性对照戊硫吡py（0.562 mg / L）。生理生化研究表明，化合物5b对灰葡萄孢的主要作用机制是改变菌丝体形态，增加细胞膜通透性，并抑制呼吸代谢中的TCA途径。此外，QSAR和SAR研究表明，松香类酰胺衍生物的电荷分布通过化合物与目标受体之间的氢键键合，结合和静电相互作用，在抗真菌活性中起着关键作用。综上所述，该研究有助于开发具有新颖结构和优选生物活性的基于松香的抗真菌剂。