Synthesis And Fungicidal Activity Against Botrytis Cinerea Of Propamidine Analogues

Propamidine belongs to compounds of aromatic diamidines, which have been used in the treatment of protozoal diseases,African trypanosomiasis, leishmaniasis, keratitis and pneumocystis carinii pneumonia.These diamidines also show antitumor and antiviral activity, especially anti-HIV activity.In prophase research of antifungi activity,propamidine has been found with high inhibitory effect against Botrytis cinerea. Primary Study on the mechanism shows the prospect of propamidine to be a new fungicide,with its new charater of inhibitory mechanism.In order to find the compounds,which are potenter and less expensive than pro-compound,i.e.propamidine,and according to the known structure-activity relationshipin in the medical and antifungi research,we have synthesized eight compounds,which have been characterized with MS ,¹H-NMR and ¹³C-NMR,and studied the inhibitory effect against Botrytis cinerea comprehensive,including the synthesis techniques of the most potenter compound.The results of the research have found as follows:(1)Eight propamidine analogues have been synthesized and characterized with MS ,1H-NMR and 13C-NMR.(2)All compounds showed inhibitory activity to Botrytis cinerea in virtro.With mycelial growth rate method, the EC₅₀ values of B3(1,3-di(N-propyl,4-bis(4-amidinophenoxy)) propane,)B4(1,4-di(N-propyl,4-bis(4-amidinophenoxy))butane),C3(1,3-di(N-isopropyl, 4-bis(4-amidinophenoxy))propane)and D3(1,3-di(N-isobutyl, 4-bis(4-amidinophenoxy)) propane)are 0.3043,1.6879,2.8751,3.4730mg/L respectively,prior to propamidine (4.3577mg/L).(3)In the inhibitory against spore bourgeon of Botrytis cinerea,the EC₅₀ values of B3,B4,C3 and D3 are 0.586mg/L,1.0518mg/L,3.8839mg/L and 3.5868mg/L respectively,B3 and B4 prior to propamidine(3.2314mg/L).(4) The protective and therapy effectiveness were experimented on cucmber leaf.At 50mg/L,the protective effectiveness of B3,B4,C3 were 81.13%,66.04%,63.21% ,respectively, better than propamidine(57.55%);The therapy effectiveness of B3(71.70%) and B4(68.87%) are superior to propamidine(64.15%).At 25mg/L,the protective and therapy effectiveness of B3(54.77%,49.61% respectively) are equaling to the same effectiveness of propamidine (49.0%,49.61% respectively). At 5mg/L,the protective and therapy effectiveness of B3 and B4 are equaling to the same effectiveness of propamidine.(5) The protective and therapy effectiveness had also been experimented on young tom- ato fruit.At 200mg/L,the protective effectiveness of B3(75.74%) are equaling to the same eff- ectiveness of propamidine(74.10%).The therapy effectiveness of B3(67.54%) is superior to the same effectiveness of propamidine. At 100mg/L,the protective effectiveness of B3(50.5%) is lower than propamidine(56.7%).The therapy effectiveness of B3(56.7%) are prior to the same effectiveness of propamidine(48.30%).At 50mg//L,the protective effectiveness of B3 (34.8%) is equaling to the same effectiveness of propamidine(35.08%).The therapy effect- tiveness of B3(37.0%) is superior to propamidine(22.1%).(6)The results of field experiments showed that :at 100mg/L,no difference between B3 (75.26%) and propamidine(69.09%) in 7 days after treatment;the control efficacy of B3 (74.45%) is better than propamidine(61.66%) in 10 days after treatement.The compound B3 showed to be potenter than propamidine.(7)Preliminary study on the synthesis of B3 indicated that the yield was as high as 80.3738% when the mixing temperature was 30℃, molar ratio of 4,4'-dicyano-1,3- diphenoxypropane and propylamine was 1:5.