Nematicidal Effect of Raphasatin from Against .

The nematicidal activity of radish bulb () methanol (RME) and aqueous extracts (RAE) was tested against the second stage (J) root knot nematode model. The EC of RME after 3 d of J immersion in test solutions was 312 ± 65 μg/ml. However, no activity was noted for RAE (EC > 1,000 μg/ml). The chemical composition analysis of the methanol extract carried out by the GC-MS technique showed that 4-methylthio-3-butenyl isothiocyanate (raphasatin) was the most abundant compound at 20%. This pure compound strongly induced J paralysis with an EC of 1.3 ± 0.2 μg/ml after 24 hr. Comparison with other 11 selected isothiocyanates with structure similarity showed that the double bond at position 3 of the alkyl side chain is important for nematicidal activity, followed by the sulfur group at position 5 and the benzyl group at position 2. In addition, raphasatin showed the highest nematicidal activity with the corresponding lowest antioxidant activity of about 92 ± 18 μg/ml. In conclusion, the results of this investigation reveal that and its major compound raphasatin can be integrated into the pest management system.