Studies On Fungicidal Constituents Of Cuminum Cyminum L.

The paper studied the fungicidal activities and fungicidal components of Cuminum cyminum L..The fungicidal compounds of the cumin seed were seperated and their chemical structures were identified by means of MS and NMR.Bioassay results showed that they had high fungicidal activities. 1.The bioactivity of petroleum ether extract from cumin seed extract had been tested.It showed great inhibition to Rhizoctomia solan,Rhizoctonia cerealis,Alternaria solani,Botrytis cinerea,Phytophthora capsici and Sclerotinia sclerotiorum under the concentration of 500 mg/L.The inhibion rates were 87.03%, 88.15% ,88.22%,92.73% ,100.00% and 100.00%,respectively.By column chomatography,chemical â… and â…¡were seperated and identified by means of MS and NMR as cuminic aldehyde (p-isopropyl benzaldehyde) and cuminic acid (p-isopropyl benzoic acid). 2.Bioactivities of cuminic aldehyde and cuminic acid were screened.Screening results indicated that the control rates of two chemicals were 100% against numerous tested fungi under the concentration of 800mg/L. 3.The bioactivity of two chemicals in vitro was tested.The EC50 of cuminic aldehyde against Sclerotinia sclerotiorum,Rhizoctomia solani,Phytophthora capsici,Rhizoctonia cerealis were 2.093mg/L,10.23 mg/L,15.40 mg/L and 36.84 mg/L ,respectively.The EC50 of cuminic acid against Sclerotinia sclerotiorum,Rhizoctomia solani,Phytophthora capsici,Rhizoctonia cerealis were 7.298 mg/L,17.14 mg/L,19.66 mg/L and 140.09 mg/L, respectively.Furthermore,the inhibition rate of two chemicals against Exserohilum turcicum were 82.92 %(cuminic aldehyde) and 79.30 %(cuminic acid) under the concentration 1000mg/L.Totally,the bioactivities of cuminic aldehyde were higher than cuminic acid. 4.Under the concentration of 1000mg/L,the protective effect of cuminic aldehyde against Erysiphe graminis and Botrytis cirerea were 52.82% and 70.39%,and the curative effect of it against Erysiphe graminis was 26.34% and had no bioactivity against Botrytis cirerea. The protective effect of cuminic acid against Erysiphe graminis and Botrytis cirerea were 65.01% and 65.64%;the curative effect of it against Erysiphe graminis and Botrytis cirerea were 42.30% and 16.20%. Two chemicals had excellent protective effect, whose control rates were higher than 50%,and had better curative activity against Erysiphe graminis than Triadimefon,under the concentration 200mg(a.i.)/L.