Study On The Synthesis And Bioactivity Of Coumarins

Coumarins with the biological activities such as anticoagulant, anti-tumor, cytotoxic activity, antioxidant, antivirus, anti-HIV-1 et al, widely consist in plants, but the contents is too low to be exploited. In this paper, the synthesis of coumarins were reaserched and fourteen compounds were synthesized. Antifungal experiment and daphnia toxicity experiment were conducted.Umbelliferone(A), scopoletin(B), E-2-hydroxy-3-methoxyethylcinnamate(C), E-2,5- dihydroxyethylcinnamate(D), ayapin(E) were synthesized by o-hydroxybenzaldehyde and ethoxycarbonylmethylenetriphenylphosphorane via Wittig reaction using KF/Al2O3 as catalyst. Ethyl 7-hydroxycoumarin-3-carboxylate (F), 7-hydroxycoumarin-3-carboxylic acid (G), Ethyl 6-hydroxycoumarin-3-carboxylate (H), Ethyl 8-methoxycoumarin-3-carboxylate (I) Ethyl 6,7-methylenedioxycoumarin-3-carboxylate (J) were synthesized by o-hydroxybenzal- dehyde and diethyl malonate via Knoevnagal reaction. 6-methoxy-7-hydroxycoumarin-3- carboxylic acid (K), 6,7-methylenedioxycoumarin-3- carboxylic acid (L) were synthesized by o-hydroxybenzaldehyde and malonic acid via Knoevnagal reaction. 7-hydroxy-4-methyl- coumarin (M), 5,7-dihydroxy-4-methylcoumarin (N) were synthesized by resorcinol or phloroglucinol and ethyl acetoacetatevia via Pechmann reaction using solid superacid (ZrO2-SO42-) as catalyst.The structures of the compounds were confirmed by IR, 1H NMR, 13C NMR and MS. We choose Fusarium solani, Valsa mali, Fusarium graminearum, Curvularia lunata, Fusarium oxysporum, Alternaria longipes, Botrytis cinerea, Phytophthora infestans as tested phytopathogenic fungi; choose acetone as control and triabendazole as positive control. The antifungal activity was tested by growth rate method. These compounds have appropriate antifungal activity in the concentration of 0.1mg/mL.Daphnia toxicity test showed that fourteen compounds have appropriate toxicity to daphnia. Among the compounds, compound F have the lowest toxicity to daphnia. And the maximum safe concentration to daphnia is 45 ~ 50μg/mL.