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Synthesis And Preliminary Bioactivities Studies Of Phenazine-1-carboxylic Acid-benzoic Acid Conjugates

Posted on:2019-06-16Degree:MasterType:Thesis
Country:ChinaCandidate:X ZhuFull Text:PDF
GTID:2371330542996519Subject:Plant protection
Abstract/Summary:PDF Full Text Request
Shenqinbactin,also called Phenazine-1-carboxylic acid(PCA),which is a natural product often isolated from the metabolites of Pseudomonas and streptomycetes and a few other bacterial genera,exhibits a very broad spectrum of antimicrobial,antitumorigenic,antitubercular and antileukemic activities.In China,PCA has been registered as a biofungicide against rice sheath blight caused by Rhizoctonia solani,and it is noted for its high efficacy,low toxicity,environmental friendliness and enhancement of crop production.Benzoic acid and its analogs are also a class of compounds with a wide range of biological activities.Therefore,in this study,taking phenazine-1-carboxylic acid as a parent compound,two series of novel phenazine-1-carboxylic acid-benzoic acid conjugates were designed and synthesized by conjugating benzoic acid and its analogs with phenazine-1-carboxylic acid through the methods of molecular design and active structure splicing.And all these conjugates were evaluated for their in vitro fungicidal activity,herbicidal activity and the systemic acquired resistance,which can provide a theoretical basis for the development of new fungicides or herbicides of this type of compounds.The main results are described as follows.16 novel Phenazine-1-carboxylic acid-benzoic acid conjugates A1-A16 were designed and synthesized by conjugating three types of benzoic acids with phenazine-1-carboxylic acid.And all these conjugates were evaluated for their in vitro fungicidal activity.The results of the bioassay indicated that the target compounds A1-A16 exhibited promising in vitro fungicidal activities against 5 tested phytopathogenic fungi.Nine conjugates were more active than PCA against Rhizoctonia solani.Especially conjugate A3,A9 and A13 showed the best fungicidal activity against Rhizoctonia solani which are 7 to 11-fold than PCA.In addition,the study indicated that the fungicidal activities of the conjugates A1-A16 against Rhizoctonia solani were associated with their Log Kow values,and the LogP values of the more potent fungicidal activity against Rhizoctonia solani within these conjugates ranged from 4.42-5.08.A series of novel Phenazine-1-carboxylic acid-benzoic acid diamide conjugates were designed and synthesized by using ethylenediamine as a bridge,and were evaluated for their in vitro fungicidal activity and in vitro herbicidal activity.The results revealed that the phenazine-1-carboxylic acid-benzoic acid diamide conjugates exhibited promising in vitro fungicidal activities against 6 tested phytopathogenic fungi,but its fungicidal activity is declined compared to the parent structure phenazine-1-carboxylic acid.However,the results of in vitro herbicidal activity showed that most of the conjugates exhibited excellent and selective herbicidal activities.Particularly,the herbicidal activities of some of these conjugates were even higher than that of the positive control Fenoxaprop-P-ethyl.For example,compound B5 exhibited the best activity against barnyard grass stalk length against rape in both root length and stalk length herbicidal activities with its IC50 values of 0.048 mM and0.059 mM respectively,which are 6 to 8-fold than positive control.The analysis of preliminary Structure-Activity Relationships implied that the substituents of the aroyl groups in the para-position indicated lower herbicidal activities than other position.And the introduction of halogen atoms,such as fluorine atom or helium atom,had no obvious effect on herbicidal activities.In conclusion,phenazine-1-carboxylic acid-benzoic acid conjugates have good in vitro fungicial activity against some phytopathogenic fungi,and PCA-SA ester conjugate A3 retained the resistance induction activity of SA.In addition,phenazine-1-carboxylic acid-benzoic acid diamide conjugates also have potent herbicidal activities against gramineae and dicotyledones.More importantly,several high-bioactivity compounds have great potential for being a new class of fungicides or herbicides.
Keywords/Search Tags:Shenqinbactin(Phenazine-1-carboxylic acid), Benzoic acids, Conjugates, Synthesis, Bioactivity
PDF Full Text Request
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