Studies On Antifungal Actions Of Cuminum Cyminum L. Seed

Cuminum cyminum L.,,was also called cumin,which was a member of the Cuminum L.family of Umbelliferae,annual or biennial herbaceous.The main usefull part of cumin was itsseed.For a long time,seed of Cuminum cyminum was used as spice and medicine.Somereport showed that cumin seed extract had many kinds of bioactivities.This paper studied thefungicidal activity of Cuminum cyminum systematically,and main results were as following:1.Through direction of bio-assay,twelve coumpounds were isolated from petroleumether extract.Six compounds were detected as p-isopropyl benzaldehyde,p-isopropyl benzoicacid,eugenol,stig-masterol,β-sitoserol,luteolin.Chemical structure of compounds numberedZR7～ZR12 need further confirmation.2.Antifungal activities of of p-isopropyl benzaldehyde and p-isopropyl benzoic acidwere researched systematically.p-isopropyl benzaldehyde showed higher antifungal virulencethan other compounds against Alternaria sonali,Verticillium dahliae and Gaeumannomycesgraminis,and the EC₅₀were 19.0 mg/L,45.3 mg/L and 62.5 mg/L respectively.It hadinhibition effect againt spore germination of some plant pathogens also.Under theconcentration of 100 mg/L,the germination inhibition rates ofp-isopropyl benzaldehyde wereamong 50%～60% against Pyricularia oryzae,Fulvia fulva and Exserohilum turcicum;Underthe concentration of 500 mg/L,it inhibited spore germination of Pyricularia oryzae,Alternaria brassicae,Fulvia fulva,Exserohilum turcicum and Alternaria alternate completely.Organic method showed p-isopropyl benzaldehyde had inhibition effect againt mycelimgrowth ofBotrytis cirerea and Sclerotinia sclerotiorum at 100 mg/L,and the inhibition rateswere 23.75% and 21.93% respectively.The potted method showed protective effect andtherapy effect of p-isopropyl benzaldehyde were 51.98% and 20.06% against Blumergraminis respectively,and were 21.71% and 26.55% against Sclerotinia sclerotiorumrespectively.p-isopropyl benzoic acid had higher antifungal virulence against Verticillium dahliae,and the EC₅₀was 46.7 mg/L.And the followed EC₅₀of which were 84.0 mg/L and 91.8 mg/Lagainst Alternaria sonali and Gaeumannomyces graminis repectively.Under theconcentration of 100 mg/L,the inhibition rates were less than 50% againt spore germinationof seven pathogens for testing.While the concentration raised to 500 mg/L,p-isopropylbenzoic acid inhibited spore germination of Fulvia fulva,Exserohilum turcicum,Alternaria alternate and Physalospora piricola completely.In the further,tissue method showed thatcontrol effect ofp-isopropyl benzoic acid was 51.15% against Sclerotinia sclerotiorum underthe concentration of 1000 mg/L.At the same concentration,potted mehod showed thatprotective effect and therapy effect of which were 64.85% and 54.17% against Blumergraminis respectively,and were 99.06% and 21.78% against Sclerotinia sclerotiorumrespectively.3.Premilary stydies on the fungicidal activities of othe 12 compounds from cumin seed.Plate growth rate method showed eugenol had better bioactivity among these compounds.Under the concentration of 200 mg/L,the inhition rates of which were 94.17%,91.24% and78.48% against Sclerotinia sclerotiorum,Alternaria solani and Verticillium dahliaerespectiviely,and inhibited hypha growth of Thanatephorus cucumeris and Rhizoctoniacerealis completely;the EC₅₀of eugenol were 64.1 mg/L and 70.3 mg/L againstThanatephorus cucumeris and Rhizoctonia cerealis respectively.ZR10,ZR12 andterpinen-4-ol took the second place.Under the concentration of 200 mg/L,inhibition rates ofZR10 were 64.43%,85.71% and 95.57% against Alternaria solani,Sclerotiniasclerotiorum and Thanatephorus cucumeris respectively;which of ZR12 were 65.45%,67.77%,79.12% and 95.71% against Phytophthora capsici,Rhizoctonia cerealis,Alternaria solani and Thanatephorus cucumeris respectively;which of terpinen-4-ol were71.68% and 77.36% against Thanatephorus cucumeris and Rhizoctonia cerealis respectively.α-terpinene,linalool,d-limonene,β-caryophyllene,1,8-Cineole,ZR8 and ZR9 hadlower inhibition effects.Under the concentration of 200 mg/L,the inhibition rates of abovecompounds were lower than 60%.Luteolin showed no inhibition effect on all test plantpathogens.4.Affection ofp-isopropyl benzaldehyde and p-isopropyl benzoic acid on infection andgrowth of Blumer graminis were observed by electron microscopy technology.Scanningelectron microscopy result showed p-isopropyl benzaldehyde and p-isopropyl benzoic acidtreating decreased sporothrix number.The former influenced sporulation,and the latterinduced premature senescence of sporothrix.Transmission electron microscopy result showedthat p-isopropyl benzoic acid treated hyphae appeared thickened cell wall,cell walldegradation,intracellular substance degradation,and some high density substances depositedinside cell wall.p-isopropyl benzaldehyde treating appeared surface irregularity of hypha,vacuole and higher density substances in cell.Two compounds improved the electron densityofhaustellum,and induced organelles separation.5.Studying the quantitative structure-activity relationship between structure and theinhition effect against Rhizoctonia cerealis and Sclerotinia sclerotiorum of 20 compounds,which had similar structure with p-isopropyl benzaldehyde and p-isopropyl benzoic acid.Twoformulas were obtained as following:Sclerotinia sclerotiorum[Y=-0.9287(â–³L-H)+0.4644(Gib)+1.0166(LogP)-0.2143(Mass)]and Rhizoctonia cerealis[Y=-0.5471 (â–³L-H)+0.4892(Gib)+ 0.6176(Volumn)—0.6281(Hydration energy)].Results showedthat aromatic compounds with unstable structure had higher bioactivity.Hydroxy group andaldehyde group were the active groups,which linked to benzene ring together had notsignificant improving on angifungal activities.Lipophilic group on other benzene ring siteshelped to impove antifungal activities of aromatic compounds.6.The SFE CO₂ optimal combination extracting of oil from cuminum cyminum seedwere researched by orthogonall test.The optimal combination was as following.Extractingpressure:5000 psi;mesh of seed power;60～80mesh;CO2 volumn:80 mL;temperature ofextracting storehouse:30℃.Under this combination,extraction rate of seed oil was 21.59%,which was higher than other extraction methods.GC/MS analysis showed that maincompounds of seed oil were p-isopropyl benzaldehyde and 4-(1-methylethyl)-p-cymen-7-ol.The relative contens of p-isopropyl benzaldehyde and 4-(1-methylethyl)-p-cymen-7-ol were30.56% and 23.59% respectively.Seed oil extracted under different combination werebioassayed against Sclerotinia sclerotiorum under the concentration of 100 mg/L.Inhibionrate and main compounds analysis showed positive correlation between inhibition effect andcontent of p-isopropyl benzaldehyde,p-isopropyl benzaldehyde was the main fungicidealcompound of seed oil from Cuminum cyminum.