Antifungal Effects and Active Components of Ligusticum chuanxiong

The separation of chemical components from wild plants to develop new pesticides is a hot topic in current research. To evaluate the antimicrobial effects of metabolites of Ligusticum chuanxiong (CX), we systematically studied the antimicrobial activity of extracts of CX, and the active compounds were isolated, purified and structurally identified. The results of toxicity measurement showed that the extracts of CX had good biological activities against Botrytis cinerea, Sclerotinia sclerotiorum, Alternaria alternata and Pythium aphanidermatum, and the value of EC50 were 130.95, 242.36, 332.73 and 307.29 mg/L, respectively. The results of in vivo determination showed that under the concentration of 1000 mg/L, the control effect of CX extract on Blumeria graminis was more than 40%, and the control effect on Botrytis cinerea was 100%. The antifungal active components of CX were identified as Senkyunolide A and Ligustilide by mass spectrometry and nuclear magnetic resonance. The MIC (minimum inhibitory concentration) value of Senkyunolide A and Ligustilide against Fusarium graminearum were 7.81 and 62.25 mg/L, respectively. As a new botanical fungicide with a brightly exploitative prospect, CX extract has potential research value in the prevention and control of plant diseases.

Isolation and structural identification of insecticidal compounds from Tripterygium wilfordii.

Five compounds were identified from Tripterygium wilfordii, including two novel compounds and three previously known compounds. Two newly discovered compounds are celangulin CY (1α,2α,3ß,4ß,6ß,8α,13-hepacetoxy-9ß-benzoyloxy-ß-dihydroagarofuran) and celangulin CQ (1α-nicotinoyloxy-2α,3ß,6ß-triacetoxy-9ß-furancarbonyloxy-13-isobutanoyloxy-4ß-hydroxy-ß-dihydroagarofuran). Their structures were determined using nuclear magnetic resonance (NMR), mass spectrometry (MS), and high-pressure liquid chromatography (HPLC). The isolated compounds were tested for insecticidal activity against the third instar larvae of Spodoptera frugiperda. Both celangulin CY and celangulin CQ exhibited significantly higher oral toxicity in the larvae than that exhibited by the three known compounds.

Active saponins from root of Pueraria peduncularis (Grah. ex Benth.) Benth. and their molluscicidal effects on Pomacea canaliculata.

BACKGROUND: Pueraria peduncularis (Grah. ex Benth.) Benth., which belongs to the Leguminosae family, exhibits resistance to many crop pests in agricultural production. Pomacea canaliculata is an important invasive snail in rice fields and causes severe yield losses. To evaluate the toxicity of P. peduncularis to P. canaliculata, in this study the molluscicidal activity of root extracts of P. peduncularis was tested against P. canaliculata; the active compounds were isolated, and the structures of these compounds were analysed using nuclear magnetic resonance (NMR) analysis and mass spectral analysis. RESULTS: Our results showed that the molluscicidal activity of the root crude extract differed between P. canaliculata with different shell diameters after treatment for 72 h. The median lethal concentration (LC50 ) was 5.511 mg L-1 against snails of 1.5 ± 0.2 cm diameter and 12.383 mg L-1 against snails of 2.5 ± 0.2 cm diameter. Furthermore, two active ingredients isolated from root methanol extracts were identified as pedunsaponin A and pedunsaponin C. Both pedunsaponin A and pedunsaponin C showed strong molluscicidal activities, with LC50 values of 3.893 and 4.252 mg L-1 , respectively, against snails with shell diameters of 1.5 ± 0.2 cm after treatment for 72 h. CONCLUSION: Pueraria peduncularis extracts exhibit high molluscicidal activity and have great potential value for exploring a molluscicide to control Pomacea canaliculata. © 2016 Society of Chemical Industry.