α-红没药醇衍生物设计与合成及抗油茶炭疽病菌活性研究OA

Since the antifungal activity of α-bisabolol against Colletotrichum gloeosporioides and its associated structure-activity relationship(SAR)remained unclear,this study designed and synthesized ten novel ester derivatives(A-J)based on its structure.The derivatives were achieved via esterification at the hydroxyl group through introducing various aliphatic fluorine containing or aromatic acyl moieties.Their structures were confirmed by¹H NMR and¹³C NMR,and the antifungal activity against C.gloeosporioides in vitro was evaluated using the mycelial growth rate method at a final concentration of 0.5 mg·mL-1.The results indicated that the antifungal activity was closely related to the ester structure.The aromatic ester derivatives(C-J)generally exhibited superior activity compared to the aliphatic fluorine-containing esters(A and B,inhibition rates<1.5%).Notably,compound C(α-bisabolol-2,5-dimethylphenylacetate),which features a phenyl group connected to the ester carbonyl via a methylene bridge,demonstrated the strongest activity with an inhibition rate of(22.32±1.26)%.Furthermore,the unsubstituted benzoate derivative D(inhibition rate of(7.82±0.34)%)was significantly more active than most substituted benzoate derivatives(E-J),suggesting that substituents on the phenyl ring might reduce the activity due to the steric hindrance or electronic effects.This study clarifies the SAR of α-bisabolol derivatives against C.gloeosporioides,identifies a highly active lead compound(C),and provides a crucial theoretical foundation for developing new green agents to control C.oleiferaanthracnose.