Studies On The Fungicidal Activities Of Carpesium Macrocephalum Franch. Et Sav.

To further exploit and utilize the excellent fungicidal plant Carpesium macrocephalum Franch. Et Sav., this dissertation carried out a systematic research on five fields of the fungicidal activities of the plant. The results showed as follows:1. 17 compounds were isolated from the plant and chemical structure of 14 compounds were identified, including 7 kinds of sesquiterpenoid lactone, 1 kind of coumarin,2 kinds of steroidal saponins and the other four kinds of compounds. Among them, 11β-methyl-6-en-7α- hydroxy-dicyclo[5.3]-decane-3-one(S6) and 6,7α-epoxy-isolindenrane-12,8β-olide (S7) were the new natural compouds that had not been reported before. 6,7α-epoxy-isolindenrane- 12,8β-olide (S8) and 11β-methyl-6-en-7α-hydroxyl-dicyclo[5,3]-decane-3-one(S6) were firstly isolated from the plant. The inhibiting effect of spore germination on two pathogens were tested. The results showed that sesquiterpenoid lactone and coumarin compounds have higher antifungal activities than others. The fungicidal activities of those compouds were firstly reported exceptβ-sitosterol,β-daucosterol and D-mannitol. In conclusion, it is sesqui- terpenoid lactone that were the main fungicidal activity compounds of C. macrocephalum.2. The fungicidal activities of Carabrone(S2), Carobrol (S7) andβ-sitosterol were assayed. The fungicidal activities of Carabrone(S2) were tested in vitro. The results showed that: S2 had high inhibition on hypae growth of 12 pathogens with an EC50 value of 4～75mg/L. S2 had the highest inhibition on hypae growth of Gaeumanno mycesgraminis var. tritici Walker and Rhizoctonia cerealis Vander Hoeven. The EC50 value was 4.9 and 12.6mg/L, respectively; inhibiting effect of spore germination of S2 against different pathogens showed significant difference. S2 had highest inhibition on spore germination of Colletotrichum langenarium with an EC50 value of 6.9mg/L. Fusarium graminearum and Exserohilum turcicum (Pass) Leonard were relatively less sensitive to S2 with EC50 values all above of 200mg/L; carabrone(S2) had good preventing and controlling effects against Erysiphe graminis (DC.) Speer, Sphaerotheca fuliginea(Schlecht)Poll., and E. turcicum. The preventing and controlling effects against 3 pathogens in pot trials were all above 55.5% under 1000mg/L concentration. The preventing and controlling effects against Botrytis cirerea Pers. et Tris were 59.7% and 47.0% under concentration 2000mg/L, these results illuminate the fungicidal activities of carabrone(S2) worth further study. Inhibiting effect of spore germination of Carobrol (S7) against different pathogens showed little difference, the EC50 of G. mycesgraminis and Phytophthora capsici Leon were 9.9 and 22.7 mg/L, respectively. The...