Abstract
Epidemic diseases of crops caused by fungi deeply affected the course of human history and processed a major restriction on social and economic development. However, with the enormous misuse of existing antimicrobial drugs, an increasing number of fungi have developed serious resistance to them, making the diseases caused by pathogenic fungi even more challenging to control. Drug repurposing is an attractive alternative, it requires less time and investment in the drug development process than traditional R&D strategies. In this work, we screened 600 existing commercially available drugs, some of which had previously unknown activity against pathogenic fungi. From the primary screen at a fixed concentration of 100 μg/mL, 120, 162, 167, 85, 102, and 82 drugs were found to be effective against Rhizoctonia solani, Sclerotinia sclerotiorum, Botrytis cinerea, Phytophthora capsici, Fusarium graminearum and Fusarium oxysporum, respectively. They were divided into nine groups lead compounds, including quinoline alkaloids, benzimidazoles/carbamate esters, azoles, isothiazoles, pyrimidines, pyridines, piperidines/piperazines, ionic liquids and miscellaneous group, and simple structure-activity relationship analysis was carried out. Comparison with fungicides to identify the most promising drugs or lead structures for the development of new antifungal agents in agriculture.
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Introduction
Plant diseases and pests lead to reduced yields and quality of crops [1,2,3], which have a major impact on economic development and food security [4]. Research revealed that more than 19,000 species of fungi could cause plant diseases and some of them could be dormant in dead plants until opportunities were conducive to their proliferation [5]. It is estimated that the average annual economic loss caused by plant pathogenic fungi exceeds $200 billion [6]. Fusarium is one of the most important plant pathogenic fungi, for example, Fusarium graminearum and Fusarium oxysporum cause head blight and root rot. They can produce mycotoxins such as monothiocarbates and fumonisin [7, 8]. Rhizoctonia solani, Sclerotinia sclerotiorum, Botrytis cinerea and Phytophthora capsici host a wide range of more than 200 crops, including fruits and vegetables [9, 10]. Thus the loss of crops caused by fungi had become a severe issue that cannot be ignored.
Currently, there are several approaches to control plant diseases, such as breeding of resistant varieties, biological control and chemical control. However, the breeding also has many drawbacks, including lengthy breeding cycles, lack of varieties and geographical limitations of breeds [11]. Although biological control is advocated, the development process of biopesticides is slow and easy to deposit, so it is difficult to be widely applied in agricultural production at present [12, 13]. Thus, agrochemicals are still the primary form of control [14]. However, an expanding number of these weed, plant disease and pest insects are no longer effectively controlled by many of the existing agrochemical tools, a trend also observed in the medical community with the rise of antibiotic resistance [15, 16]. In particular, the development of resistance to critical fungicides against major crop fungal diseases, such as benzimidazoles and strobilurins, has had a significant impact on the fungicide market and the discovery of agrochemicals [17]. Therefore, it is necessary to develop novel, practical and resistant fungicidal agents to control plant diseases.
Drug development is an expensive, time-consuming and risky process [18]. In general, it can take up to 20 years for a drug from initial discovery to market. The development process can cost up to $2 billion, with only a 5% chance of successfully completing clinical trials and reaching the market [19, 20]. Likewise, an agrochemical takes 10–12 years from discovery to market and costs an estimated $286 million to develop [15, 21, 22]. Thus, it poses challenges to the development of novel pesticides. Drug repositioning or finding novel indications for known drugs is a way to reduce the time and cost of drug discovery as the toxicity, pharmacokinetic and biological activity of these drugs are well defined. In the medical field, many drugs have been successfully applied through repositioning [23,24,25,26]. As such, it has proven to be a preferred and advantageous alternative strategy for the more rapid discovery of new applications for drugs [27].
On this basis, 600 approved drugs with different structures and functions against Rhizoctonia solani, Sclerotinia sclerotiorum, Botrytis cinerea, Phytophthora capsici, Fusarium graminearum and Fusarium oxysporum were screened in this study and served as a theoretical basis for pesticide development.
Materials and methods
Fungal strains
Six phytopathogenic fungi, named R. solani, S. sclerotiorum, B. cinerea, P. capsici, F. graminearum and F. oxysporum were isolated, purified and identified from susceptible plants cultivated at the Gansu Academy of Agricultural Sciences, China.
Approved drugs
The 600 approved drugs were purchased from commercial suppliers. Drugs were delivered in centrifugal tube (100 μg ml−1, dissolved in DMSO) and kept at −80 °C until use.
Screening Assay
In vitro, the antifungal activity of the drugs was initially evaluated using mycelial growth inhibition assay [6] with some modifications. The dissolved drug was added to the PDA medium so that the concentration of PDA containing the drug was 100 μg/mL. Zero point five percent DMSO (v/v) was added to the PDA medium as a blank control. The six plant pathogenic fungi were used to evaluate the antifungal activity of the samples. Take the disc (5.00 mm diameter) from the edge of the mycelia of the active colony with a hole punch, and then pick it to the center of the drug-containing plate with the inoculating needle. Lastly, the plates were incubated upside down in the dark at 26 °C. Three replicates per treatment. The diameter of the inhibition zone (mm) was measured by the cross method using digital calipers, and the growth inhibition rate of the samples on the fungal mycelium was calculated according to the following formula.
The C and T are the average diameter of fungal colonies in the control and treated groups, respectively.
On the basis of the initial screening for antifungal activity, the highly active drugs were selected for virulence effect determination. The PDA medium was diluted to different solution concentrations (50 μg ml−1, 25 μg ml−1, 10 μg ml−1, etc.), and the plates were incubated upside down in the dark at 26 °C. The inhibition rate as above, and the antifungal activity was indicated as EC50.
Statistical Analysis
The statistical analysis was conducted by SPSS 24.0. The EC50 values were derived from the parameters in the regression curves.
Results
The preliminary screening of 600 approved drugs against six phytopathogenic fungi at 100 μg ml−1 showed that 120, 162, 167, 85, 102 and 82 drugs against R. solani, S. sclerotiorum, B. cinerea, P. capsici, F. graminearum and F. oxysporum, respectively, inhibiting the growth of mycelium of by more than 70% (Fig. 1) . To further determine the antifungal activity of these drugs, they were evaluated using the EC50. We considered drugs with EC50 less than 25 μg ml−1 as candidates. Their original uses and toxicity are shown in Table 1 (https://pubchem.ncbi.nlm.nih.gov/, November 2022). As drug repurposing has gained tremendous popularity in the pharmaceutical field, we divided the candidate drugs into 9 lead series and conducted a brief discussion of structure and activity.
Fungicides against plant pathogenic fungi
Plant pathogens can cause crop yield reduction and quality deterioration, and control of plant diseases is still dominated by chemical fungicides. We evaluated the in vitro activity of the fungicide in Fig. 2. Carbendazim and thiophanate-methyl were broad-spectrum fungicides belonging to the benzimidazole and substituted benzene fungicides respectively, with EC50 values in the range of 0.14–22.12 μg ml−1 for pathogenic fungi. They had excellent activity against S. sclerotiorum, with EC50 was 0.68 and 0.53 μg ml−1, respectively. Difenoconazole is a sterol demethylation inhibitor with systemic, prophylactic and therapeutic effects. It had relatively potent activity against five pathogens except for R. solani, especially F. oxysporum, with an EC50 of 0.04 μg ml−1. Boscalid was a novel nicotinamide fungicide with positive action against R. solani, S. sclerotiorum, B. cinerea and F. graminearum, with EC50 < 2 μg ml−1. Azoxystrobin and kresoxim-methyl were strobilurin fungicides with good activity against S. sclerotiorum with EC50 of 4.9 and 4.66 μg ml−1, respectively. Pyrimethanil and thirluzamide belong to the genus of methyl pyrimidine and benzamides, respectively. They were potent pesticides against B. cinerea and R. solani with EC50 was 3.89 and 0.054 μg ml−1, respectively. We evaluated the different classes of fungicides against plant pathogens to provide a basis for the activity level of the drugs screened for this study.
Quinoline alkaloids
Alkaloids are a class of alkaline nitrogen-containing organic compounds in plants, marine organisms, microorganisms and insects. They have a wide range of biological activities such as lowering blood pressure, anti-tumor, central nervous system, lowering blood glucose, lowering blood lipids, insect repellent and anti-microbial [28,29,30,31,32]. Therefore they show potential for application in medical treatment and agricultural insecticide. In previous studies, our team designed and synthesized a variety of quinoline alkaloid derivatives based on different structures of natural product alkaloids, and tested their activity against plant pathogenic fungi [33,34,35,36,37,38,39,40] (Table 2), which provided a theoretical basis and laid a solid foundation for the development and application of alkaloids. To further obtain a broader spectrum of effective anti-phytopathogenic fungal alkaloids, the 28 drugs with different biological functions were repositioned (Table 3), and 6 compounds with better anti-phytopathogenic fungal activities were obtained, as shown in Table 1 and Fig. 3. Among them, pitavastatin calcium had a relatively broad spectrum of activity against pathogenic fungi, particularly against B. cinerea, P. capsici and F. oxysporum, with EC50 of less than 1 μg ml−1. However, cabozantinib showed more excellent activity against R. solani, with EC50 of 0.032 μg ml−1, which may be the introduction of 1-methoxy-4-methylbenzene into the quinoline structure to enhance the antifungal activity. In addition, dequalinium chloride, mefloquine hydrochloride and bedaquiline showed potential against B. cinerea or S. sclerotiorum. Therefore, the quinoline alkaloids designed and synthesized in our laboratory, as well as the repositioning of other functional alkaloids, we found that alkaloids have great potential in the field of agricultural disease control.
Benzoimidazole/carbamate drugs
Benzimidazoles and their derivatives are an essential group of active agents in pesticides and pharmaceuticals with broad-spectrum biological activities, such as anticancer [41], antibacterial [42], antiviral [43] and antiparasitic [44]. Likewise, carbamates are a group of insecticides with outstanding bioactivity, which have properties such as rapid decomposition, short residual period and low bioaccumulation [45, 46]. On this basis, we screened 26 drugs against pathogenic fungi, as shown in Table 4, and screened out 11 drugs with excellent action, as shown in Table 1 and Fig. 4, which laid the foundation for searching for lead compounds with good activity.
The structure-activity relationship showed that drugs attached to the benzene ring to n-butyl had positive activity against R. solani and S. sclerotiorum with EC50 of 0.051 μg ml−1 and 0.16 μg ml−1, respectively, while replacing the C atom in n-butyl with an S atom (fenbendazole) or O atom (oxibendazole) had an insignificant effect on activity. However, the S-atom in n-butyl was replaced by sulfur monoxide (albendazole S-oxide), significantly less active against both pathogens. The acetophenone structure (mebendazole) exhibited positive inhibition activity against R. solani and S. sclerotiorum. But the introduction of an F-atom into the acetophenone structure (flubendazole) significantly reduced the inhibition activity against R. solani (EC50 > 25 μg ml−1). Surprisingly, the substitution of the acetophenone with the phenyl sulfane moiety (fenbendazole) showed significant inhibitory activity against R. solani and S. sclerotiorum with EC50 of 0.007 μg ml−1 and 0.097 μg ml−1 respectively. However, the replacement of the S atom by the sulfoxide resulted in significantly reduced activity against both pathogens. By comparing the activity of benzimidazole/carbamate against plant pathogens, we found that iodopropynyl butylcarbamate was effective in expanding the antifungal spectrum and had promising activity against pathogenic fungi. Thus the repositioning of benzoimidazoles/carbamates can be an effective way to expand their application areas.
Azole drugs
Azoles drugs have a wide range of applications in agriculture and medicine, such as low cost, availability and bioavailability, making azoles drugs of choice treating of fungal infections in most HIV/AIDS patients [47]. In agricultural production, triazole fungicides are mainly used to control plant fungal diseases caused by rust and mulberry powdery mildew pathogens due to their high efficiency and low toxicity [48]. The results indicate that azoles have broad antifungal activity as an essential backbone, which offers the possibility of developing new drugs. We screened 46 azole drugs (Table 5) against plant pathogens and obtained 16 drugs with optimal activity, as shown in Table 1 and Fig. 5.
The activity of bifonazole and clotrimazole showed that clotrimazole was more active than bifonazole against R. solani and S. sclerotiorum, which may be related to 1-benzyl-1H-imidazole. Econazole, vagistat, isoconazole nitrate and fenticonazole nitrate shared the basic structure (1-(2-(2,4-dichlorophenyl)-methoxy-2-ethyl)−1H-imidazole) and had comparable activity against all pathogens. All the compounds showed excellent activity against P. capsici with EC50 < 0.06 μg ml−1, indicating that this basic structure played a vital role in anti-pathogenic fungi. Replacing the O atom in the basic structure above with an S atom (sulconazle nitrate) had little effect on the activity against the plant pathogens, suggesting that the basic structure was still the key to activity. Voriconazole, efinaconazole and isavuconazole had similar basic structures, but efinaconazole showed better activity than the other two drugs with EC50 of 0.095 μg ml−1 and 0.035 μg ml−1 against S. sclerotiorum and F. oxysporum, respectively. The activity of ketoconazole against plant pathogens was significantly higher than that of terconazole, and the EC50 was in the range of 0.12–2.34 μg ml−1, which showed that 1-methyl-1H-imidazole was more effective than 1-methyl-1H − 1,2,4-triazole in this type of drug. However, not all drugs containing 1-methyl-1H − 1,2,4-triazole structures were less active against pathogens than 1-methyl-1H-imidazole. Itraconazole and posaconazole showed the strongest inhibitory activity against pathogens with EC50 < 0.17 μg ml−1. In summary, the azole backbone is the main active group against plant pathogenic fungi with a view to repositioning old drugs for plant disease control.
Isothiazolinone drugs
Isothiazolinone is a major industrial bactericide, antiseptic and anti-enzyme agent, with outstanding inhibition of mold, algae and other microorganisms [49]. Recently, a series of derivatives with anti-tuberculosis and lipase inhibitors have been designed and synthesized [50, 51]. We selected 26 isothiazolinones (Table 6) for screening against phytopathogenic fungi and obtained 8 drugs with good activity, which were briefly analysed in Table 1 and Fig. 6.
The 5-chloro-3-hydroxyisothiazole was the introduction of a Cl atom to the isothiazol-3-one structure, which significantly increased the activity against plant fungi with an EC50 in the range of 0.98–4.06 μg ml−1, but the introduction of a methyl group to 5-chloro-3-hydroxyisothiazole decreased the antifungal activity. The introduction of a Cl atom and octane on the 5-chloro-3-hydroxyisothiazole structure resulted in increasing activity against phytopathogenic fungi with an EC50 in the range of 0.27–2.64 μg ml−1. However, 2-octyl-2H-isothiazol-3-one showed comparable activity against plant pathogens compared to 4,5-dichloro-2-octyl-isothiazolone. Therefore, the introduction of octane in this structure may enhance the activity of phytopathogenic fungi, compared to 1,2-benzisothiazol-3(2H)-one, 2-methyl-1,2-benzothiazol-3(2H)-one and 6-fluoro-1,2-benzoisothiazol-3(2H)-one showed reduced antifungal activity, indicating that the introduction of substituents in this structure (benzoisothiazole) reduced the antifungal activity. Overall, the isothiazolinone structure is a potential lead compound against phytopathogenic fungi.
Pyrimidine drugs
Pyrimidine derivatives play an important role in insecticide, fungicide, weed control, antiviral, anticancer, etc. [52, 53], and have been the focus of attention of major pesticide companies in the world. In this study, we screened 65 drugs (Table 7) against agropathogenic fungi and obtained 10 highly active drugs, as shown in Table 1 and Fig. 7.
Taking 5-fluorouracil as a backbone, a molecule ((2R,3S,4R,5S)−2-(hydroxymethyl)-tetrahydrofuran-3,4-diol) was introduced to become 5-fluorouridine, which significantly enhanced its activity against plant pathogenic fungi. Compared with 5-fluorouridine, the structure of floxuridine was one less OH group, but it was slightly less active against S. sclerotiorum and B. cinerea. It showed that the introduction of this moiety directly affected the anti-pathogenic fungal activity of the compound. Compared to ganciclovir, 2'-deoxyguanosine was less active against S. sclerotiorum. The pyrimidine-4-amine-based compounds showed inhibitory activity against B. cinerea with an EC50 range of 2.29–13.52 μg ml−1. Both dabrafenib and sulfatinib contain N-methylmethanesulfonamide, which were active against S. sclerotiorum and B. cinerea, and had superior antifungal activity to sulfamitinib. Thus, the activity of pyrimidine analogues against phytopathogenic fungi are based on the pyrimidine structure with other moieties, which are beneficial to improve the activity and can be used as candidate lead compounds against plant pathogenic fungi.
Pyridine drugs
In agriculture, pyridines are used as insecticides, herbicides and plant growth regulators. In particular, in herbicides, a number of highly effective and low-toxicity varieties have been developed, such as pyrimethanesulfuron, pirimicarb and acetamiprid [54]. In this study, 31 drugs that have not yet been applied against plant pathogenic fungi were screened, as shown in Table 8, and 12 drugs with application potential were finally screened out, as shown in Table 1. We aim to obtain lead structures or drugs with triple action of insecticide, herbicide, and disease control.
As shown in Fig. 8, nilvadipine, nimodipine, amlodipine and amlodipine maleate belonged to the dihydropyridine group and showed activity against B. cinerea, among which nilvadipine had the strongest activity with an EC50 of 5.74 μg ml−1. This may be related to the electron-absorbing groups attached to the pyridine ring. Amlodipine maleate was a salt form of amlodipine with a slightly increased activity against B. cinerea. Liranaftate and pyributicarb had broad-spectrum and excellent activity against plant phytopathogens. Compared with liranaftate and pyributicarb, the activity of benzene ring-linked the cyclohexane ring with benzene ring-linked tert-butyl ring was one order of magnitude higher against five pathogenic fungi except F. oxysporum, among which the activity against B. cinerea was the best, with EC50 of 0.004 μg ml−1. The results suggest that pyridines, especially liranaftate and pyributicarb are promising for repositioning as fungicides for the control of plant pathogens.
Piperidine/Piperazine drugs
Piperidine ring and piperazine group are often introduced into many drug molecules to improve the pharmacokinetic properties by effectively adjusting the ratio of lipid-water distribution and acid-base balance of drugs, which improves the bioavailability of drug molecules and drug efficacy [55,56,57,58]. In this study, mainly 65 antipsychotics were used to screen agricultural fungi, as shown in Table 9, and 18 drugs with relatively good activity were obtained as shown in Table 1.
As shown in Fig. 9, the drugs with piperazine and piperidine structures include two forms of N-methyl group on the outside and inside, and the two forms of piperazine drugs have little difference against antifungal activity. But loratadine and penfluridol had excellent activity with EC50 of 6.19 μg ml−1 and 6.59 μg ml−1 against R. solani and S. sclerotiorum, respectively. Compared with the piperazine structure with the N-methyl position on the outside, the piperidine structure had better anti-phytopathogenic activity. Among them, trifluoperazine not only had significant antifungal activity but also expanded the antifungal spectrum. In addition, ponatinib had the best activity against R. solani. The EC50 was 0.017 μg ml−1. Therefore, piperazine and piperidine compounds have the potential to develop drugs against agricultural pathogenic fungi.
Ionic liquids
Ionic liquids are considered a friendly solvent and commonly used in the extraction of natural products. They are mainly classified as quaternary ammonium ionic liquids, pyridine ionic liquids, quaternary phosphate ionic liquids and imidazole ionic liquids [59, 60]. This study used 37 ionic liquids to inhibit plant pathogens as shown in Table 10. According to Table 1 and Fig. 10, 15 potential drugs were briefly analyzed in order to apply them to agriculture.
In all ionic liquids, we found that the longer the carbon chain of the drug, the better the activity against S. sclerotiorum. 1-Dodecyl-3-methylimidazolium chloride products better active with EC50 of 6.12 μg ml−1 against S. sclerotiorum. Compared to 1-dodecylpyridinium bromide, 1-tetradecylpyridinium chloride was less active against phytopathogenic fungi despite the carbon-chain length, so the effect on antifungal activity may be ion-related. 1-Dodecylpyridinium with the bromine ion increased the activity against S. sclerotiorum, B. cinerea and F. oxysporum. Compared to myristalkonium chloride, the carbon chain increased and the activity was enhanced against S. sclerotiorum with cetalkonium chloride EC50 of 8.36 μg ml−1, but significantly decreased activity against B. cinerea. Compared with benzyldodecyldimethylammonium bromide, chloride ion replaced by bromine ion dodecyl dimethyl benzyl ammonium bromide increased the activity of S. sclerotiorum and B. cinerea. The EC50 values were 5.80 μg ml−1 and 8.85 μg ml−1, respectively. In summary, the carbon chain length of the ionic liquid drugs had a significant effect on the resistance to phytopathogenic fungi. Compared to chlorohexidine diacetate, enebicyanog had a narrower spectrum of activity against phytopathogenic fungi, but it had better activity against S. sclerotiorum and B. cinerea, with EC50 of 0.91 μg ml−1 and 0.62 μg ml−1 respectively. Therefore, ionic liquids are expected to be used in the control of plant resistant pathogenic fungi.
Miscellaneous group drugs
Miscellaneous group drugs against plant pathogenic fungi are shown in Table 11 and Table 1. Some drugs with relatively broad anti-pathogenic activity were selected for a brief analysis as shown in Fig. 11.
Monensin, natamycin and griseofulvin are antibiotics, but they have different effects, which monensin inhibits the growth of coccidia, gram-positive bacteria, algae and protozoa [61]. Natamycin is commonly used as a preservative to prevent mould contamination in food [62, 63]. Griseofulvin is widely used in clinical medicine to treat skin and stratum corneum fungal infections, and also in the prevention and treatment of fungal diseases in agriculture [64]. Monensin sodium salt, natamycin and griseofulvin had broad-spectrum activity against plant pathogenic fungi, with EC50 ranging from 0.076 to 13.20 μg ml−1. Butenafine hydrochloride, terbinafine hydrochloride and tolnaftate are a group of antifungal drugs, which are applied to the treatment of tinea capitis and other tinea diseases [65, 66]. In this screening, butenafine hydrochloride, terbinafine hydrochloride and tolnaftate were also found to have excellent activity against pathogenic fungi, with EC50 in the range of 0.07–18.05 μg ml−1. It was worth noting that they had significant activity in B. cinerea, with EC50 of 0.07, 0.11 and 0.07 μg ml−1, respectively. Oxyclozanide is the drug of choice for clinical anti-helminth infections, which has the characteristics of broad spectrum, low toxicity and low residue [67]. Through drug repositioning strategy, we found that oxyclozanide also had excellent activity against phytopathogenic fungi with EC50 in the range of 0.09–0.71 μg ml−1. Carbonyl cyanide 3-chloro-phenylhydrazone (CCCP) is an inhibitor of oxidative phosphorylation that disrupts the mitochondrial membrane potential [68]. The evaluation of the in vitro activity of CCCP against pathogenic fungi revealed a broad antifungal spectrum and potent activity with EC50 in the range of 0.38–6.07 μg ml−1. Although this group of drugs was not analyzed by activity and structure, these results provided a structure-based screening approach to repurpose commercially available drugs with the expectation of discovering broad-spectrum, effective drugs against plant pathogens.
Discussion and conclusion
In an era of emerging drug resistance, there is an increasing need to optimise old drugs or develop new ones to alleviate the problem. In this worrying situation, drug repurposing is a promising approach as a way to obtain effective drugs or lead structures to solve the problem. In the field of medicine, studies have been carried out with drug repurposing strategies to re-screen approved library for potential anti-tumour, anti-inflammatory, antituberculous, antimicrobial drugs [23, 69,70,71,72,73,74]. Similarly, in the agricultural field, the potential of halofuginone, kaempferol, honokiol and tavaborole against agricultural pathogens has also been identified [75,76,77,78]. In addition, novel lead structures can also be found through drug repurposing. Antibacterial conversion of neamine aminoglycosides through alkyl modification could turn old drugs into agricultural fungicides [79]. In this paper, we can obtain some potential drugs or lead structures against agricultural pathogenic fungi by screening. However, studies have found that for some repurposed drugs, the original mechanism of action may become a negative side effect of the new indication. Thus, maintaining the positive effects of the new indication while eliminating the original mechanism of the drug is a more attractive study. Conversely, the study show that several AHAS inhibitors developed as commercial herbicides are powerful accumulative inhibitors of C. albicans AHAS [80]. This provides two different directions for our subsequent research.
We have obtained 150 drug candidates through activity screening and many of the compounds had low acute toxicity. Surprisingly, we found that benzoimidazole/carbamate drugs (parbendazole, fenbendazole, mebendazole) (Fig. 4) and azole drugs (econazole, isoconazole nitrate, clotrimazole) (Fig. 5) showed excellent activity against plant pathogenic fungi and low toxicity. In this article benzoimidazole/carbamate drugs (parbendazole, fenbendazole, mebendazole) are mainly used as anthelmintics. The original use of halofuginone was found to be an anticoccidial. Through a drug repurposing strategy, it was found to have excellent activity against Phytophthora [78]. Therefore, we hope to obtain potential drugs or lead structures against plant pathogenic fungi through this strategy, which will provide the possibility for the development of agricultural fungicides.
References
Bebber DP, Holmes T, Gurr SJ. The global spread of crop pests and pathogens. Glob Ecol Biogeogr. 2014;23:1398–407.
Stukenbrock EH, McDonald BA. The origins of plant pathogens in agro-ecosystems. Annu Rev Phytopathol. 2008;46:75–100.
Zhang Q, Men X, Hui C, Ge F, Ouyang F. Wheat yield losses from pests and pathogens in China. Agric Ecosyst Environ. 2022;326:107821.
Horbach R, Navarro-Quesada AR, Knogge W. When and how to kill a plant cell: Infection strategies of plant pathogenic fungi. J Plant Physiol. 2011;168:51–62.
Jain A, Sarsaiya S, Wu Q, Lu Y, Shi J. A review of plant leaf fungal diseases and its environment speciation. Bioengineered. 2019;10:409–24.
Li Y, Aioub AAA, Lv B, Hu Z, Wu W. Antifungal activity of pregnane glycosides isolated from Periploca sepium root barks against various phytopathogenic fungi. Ind Crops Prod. 2019;132:150–55.
Dean R, Van Kan Ja Fau - Pretorius ZA, Pretorius Za Fau - Hammond-Kosack KE, Hammond-Kosack Ke Fau - Di Pietro A, Di Pietro A Fau - Spanu PD, Spanu Pd Fau - Rudd JJ, et al. The Top 10 fungal pathogens in molecular plant pathology. Mol Plant Pathol. 2012;13:414–30.
He Z, Zhang J, Shi D, Gao B, Wang Z, Zhang Y, et al. Deoxynivalenol in Fusarium graminearum: Evaluation of Cyproconazole Stereoisomers in vitro and in planta. J Agric Food Chem. 2021;69:9735–42.
Aqueveque P, Céspedes CL, Alarcón J, Schmeda-Hirschmann G, Cañumir JA, Becerra J, et al. Antifungal activities of extracts produced by liquid fermentations of Chilean Stereum species against Botrytis cinerea (grey mould agent). Crop Prot. 2016;89:95–100.
Fisher MC, Henk Da Fau -, Briggs CJ, Briggs Cj Fau -, Brownstein JS, Brownstein Js Fau -, et al. Emerging fungal threats to animal, plant and ecosystem health. Nature. 2012;484:186–94.
Chuan YH. The screening of biocontrol agents against fusarium head blight and the research on Frenolicin B against the disease. (Doctoral dissertation) Northeast Agricultural University 2020.
Jochum CC, Osborne LE, Yuen GY. Fusarium head blight biological control with Lysobacter enzymogenes strain C3. Biol Control. 2006;39:336–44.
Schisler DA, Khan NI, Boehm MJ. Biological control of Fusarium head blight of wheat and deoxynivalenol levels in grain via use of microbial antagonists. Adv Exp Med Biol. 2002;504:53–69.
Wang L, Li C, Zhang Y, Qiao C, Ye Y. Synthesis and biological evaluation of benzofuroxan derivatives as fungicides against phytopathogenic fungi. J Agric Food Chem. 2013;61:8632–40.
Sparks TC, Lorsbach BA. Perspectives on the agrochemical industry and agrochemical discovery. Pest Manag Sci. 2017;73:672–77.
Ribas e Ribas AD, Spolti P, Del Ponte EM, Donato KZ, Schrekker H, Fuentefria AM. Is the emergence of fungal resistance to medical triazoles related to their use in the agroecosystems? A mini review. Braz J Microbiol. 2016;47:793–99.
Hermann D, Stenzel K. FRAC mode-of-action classification and resistance risk of fungicides. Mod Crop Prot Compd. 2019;14:589–608.
Zheng W, Sun W, Simeonov A. Drug repurposing screens and synergistic drug-combinations for infectious diseases. Br J Pharmacol. 2018;175:181–91.
DiMasi JA, Hansen RW, Grabowski HG. The price of innovation: new estimates of drug development costs. J Health Econ. 2003;22:151–85.
Wall G, Lopez-Ribot JL. Screening repurposing libraries for identification of drugs with novel antifungal activity. Antimicrob Agents Chemother. 2020;64:e00924.
Demarque DP, Espindola LS. Challenges, advances, and opportunities in exploring natural products to control arboviral disease vectors. Front Chem. 2021;9:779049.
Tcs A, Fjw B, Bal B, Bmn B. The new age of insecticide discovery-the crop protection industry and the impact of natural products. Pestic Biochem Physiol. 2019;161:12–22.
An Q, Li C, Chen Y, Deng Y, Yang T, Luo Y. Repurposed drug candidates for antituberculosis therapy. Eur J Med Chem. 2020;192:112175.
Stylianou M, Kulesskiy E Fau - Lopes JP, Lopes Jp Fau - Granlund M, Granlund M Fau - Wennerberg K, Wennerberg K Fau - Urban CF, Urban CF. Antifungal application of nonantifungal drugs. Antimicrob Agents Chemother. 2014;58:1055–62.
Serafin MB, Bottega A, Foletto VS, da Rosa TF, Machado CS, Coelho SS, et al. Drug repurposing identifies new promising treatment options for invasive fungal diseases. Clin Ther. 2019;41:2454–59.
Mohammad H, AbdelKhalek A, Abutaleb NS, Seleem MN. Repurposing niclosamide for intestinal decolonization of vancomycin-resistant enterococci. Int J Antimicrob Agents. 2018;51:897–904.
Abdelkhalek A, Mohammad H, Mayhoub AS. Screening for potent and selective anticlostridial leads among FDA-approved drugs. J Antibiot. 2020;73:392–409.
Hu YQ, Gao C, Zhang S, Xu L, Xu Z, Feng LS, et al. Quinoline hybrids and their antiplasmodial and antimalarial activities. Eur J Med Chem. 2017;139:22–47.
Karad SC, Purohit VB, Thakor P, Thakkar VR. Novel morpholinoquinoline nucleus clubbed with pyrazoline scaffolds: Synthesis, antibacterial, antitubercular and antimalarial activities. Eur J Med Chem. 2016;112:270–9.
Mohamed F, El S, Mostafa M, et al. Quinoline derivatives bearing pyrazole moiety: Synthesis and biological evaluation as possible antibacterial and antifungal agents. Eur J Med Chem. 2018;143:1463–73.
Yang GZ, Zhu JK, Yin X, Yan YF, Wang YL, Shang XF. et al. Design, synthesis, and antifungal evaluation of novel quinoline derivatives inspired from natural quinine alkaloids. J Agric Food Chem. 2019;67:11340–53.
Cinelli MA, Jones AD. Alkaloids of the genus datura: review of a rich resource for natural product discovery. Molecules. 2021;26:2629.
Zhu JK, Gao JM, Yang CJ, Shang XF, Zhao ZM, Lawoe RK, et al. Design, synthesis, and antifungal evaluation of neocryptolepine derivatives against phytopathogenic fungi. J Agric Food Chem. 2020;68:2306–15.
Hua L. Study on the design and synthesis of cryptolepine derivatives, structure-activity relationship, and its mechanism. (Master’s thesis) Lanzhou University 2020.
Chen YJ, Liu H, Zhang SY, Li H, Ma KY, Liu YQ, et al. Design, synthesis, and antifungal evaluation of cryptolepine derivatives against phytopathogenic fungi. J Agric Food Chem. 2021;69:1259–71.
Kun YM. The development of new quinoline antifungal chemical entities inspired from natural Quinine Alkaloids-III. (Master’s thesis) Lanzhou University 2021.
Chu QR, He YH, Tang C, Zhang ZA-O, Luo XF, Zhang BQ, et al. Design, synthesis, and antimicrobial activity of quindoline derivatives inspired by the cryptolepine alkaloid. J Agric Food Chem. 2022;70:2851–63.
Yang CJ, Li HX, Wang JR, Zhang ZJ, Wu TL, Liu YQ, et al. Design, synthesis and biological evaluation of novel evodiamine and rutaecarpine derivatives against phytopathogenic fungi. Eur J Med Chem. 2022;227:113937.
Zhou Y, Yang CJ, Luo XF, Li AP, Zhang SY, An JX, et al. Design, synthesis, and biological evaluation of novel berberine derivatives against phytopathogenic fungi. Pest Manag Sci. 2022;78:4361–76.
Wang RX, Du SS, Wang JR, Chu QR, Tang C, Zhang ZA-O, et al. Design, synthesis, and antifungal evaluation of Luotonin a derivatives against phytopathogenic fungi. J Agric Food Chem. 2021;69:14467–77.
Shrivastava N, Naim MJ, Alam MJ, Nawaz F, Ahmed S, Alam O. Benzimidazole scaffold as anticancer agent: synthetic approaches and structure-activity relationship. Arch Pharm. 2017;350:e1700040.
Picconi P, Hind C, Jamshidi S, Nahar K, Clifford M, Wand ME, et al. Triaryl Benzimidazoles as a new class of antibacterial agents against resistant pathogenic microorganisms. J Med Chem. 2017;60:6045–59.
Youssif, Bahaa GM, Mohamed, Yaseen AM, Mukai C, et al. Synthesis of some benzimidazole derivatives endowed with 1,2,3-triazole as potential inhibitors of hepatitis C virus. Acta Pharm. 2016;66:219–31.
Goodwin KD, Lewis MA, Tanious FA, Tidwell RR, Wilson WD, Georgiadis MM, et al. A high-throughput, high-resolution strategy for the study of site-selective DNA binding agents: analysis of a "highly twisted" benzimidazole-diamidine. J Am Chem Soc. 2006;128:7846–54.
Ghoraba Z, Aibaghi B, Soleymanpour AJE, Safety E. Ultrasound-assisted dispersive liquid-liquid microextraction followed by ion mobility spectrometry for the simultaneous determination of bendiocarb and azinphos-ethyl in water, soil, food and beverage samples. Ecotoxicol Environ Saf. 2018;165:459–66.
Wang X, Meng X, Wu Q, Wang C, Wang Z. Solid phase extraction of carbamate pesticides with porous organic polymer as adsorbent followed by high performance liquid chromatography-diode array detection. J Chromatogr A. 2019;1600:9–16.
Benhamou RI, Bibi M, Steinbuch KB, Engel H, Levin M, Roichman Y, et al. Real-time imaging of the azole class of antifungal drugs in live candida cells. ACS Chem Biol. 2017;12:1769–77.
Robbertse B, Rijst M, Aarde I, Lennox C, Crous PW. DMI sensitivity and cross-resistance of Rhynchosporium secalis isolates from South Africa. Crop Prot. 2001;20:97–102.
Wang XX, Zhang TY, Dao GH, Hu HY. Interaction between 1,2-benzisothiazol-3(2H)-one and microalgae: Growth inhibition and detoxification mechanism. Aquat Toxicol. 2018;205:66–75.
Castelli R, Scalvini L, Vacondio F, Lodola A, Anselmi M, Vezzosi S, et al. Benzisothiazolinone derivatives as potent allosteric monoacylglycerol lipase inhibitors that functionally mimic sulfenylation of regulatory cysteines. J Med Chem. 2020;63:1261–80.
Liang L, Haltli BA, Marchbank DH, Fischer M, Kerr RG. Discovery of an isothiazolinone-containing antitubercular natural product Levesquamide. J Org Chem. 2020;85:6450–62.
Aastha M, Tanya P, Tripti S. Pyrimidine: a review on anticancer activity with key emphasis on SAR. Future J Pharm Sci. 2021;7:123.
Chen MH, Wu WN, Chen LJ. Progresses on the pyrimidine derivatives as agrochemical fungicides. Agrochemicals. 2017;56:474–77.
Bakhite EA, Abd-Ella AA, El-Sayed MEA, Abdel-Raheem SAA. Pyridine derivatives as insecticides. Part 2: Synthesis of some piperidinium and morpholinium cyanopyridinethiolates and their insecticidal activity. J Saudi Chem Soc. 2017;21:95–104.
Salmanpour M, Tamaddon A, Yousefi G, Mohammadi-Samani S. "Grafting-from" synthesis and characterization of poly (2-ethyl-2-oxazoline)-b-poly (benzyl L-glutamate) micellar nanoparticles for potential biomedical applications. Bioimpact. 2017;7:155–66.
Huang JJ, Zhang ZH, He F, Liu XW, Xu XJ, Dai LJ, et al. Novel naftopidil derivatives containing methyl phenylacetate and their blocking effects on α1D/1A-adrenoreceptor subtypes. Bioorg Med Chem Lett. 2018;28:547–51.
Ma H, Lu W, Sun Z, Luo L, Geng D, Yang Z, et al. Design, synthesis, and structure-activity-relationship of tetrahydrothiazolopyridine derivatives as potent smoothened antagonists. Eur J Med Chem. 2015;89:721–32.
Li DK, Wei W. Synthesis and antitumor activity of Tetrahydroimidazo[2',1': 2,3]thiazolo[5,4-c]piperdine derivatives. Chin J Appl Chem. 2017;34:905–11.
Chen YT, Xiao MP, Cui QL. Progress in the application of ionic liquids in the extraction of natural products. Guid J Tradit Chin Med Pharm. 2019;25:67–71.
Lebedeva O, Kultin D, Zakharov A, Кustov L. Advances in application of ionic liquids: fabrication of surface nanoscale oxide structures by anodization of metals and alloys. Surf Interfaces. 2022;34:102345.
Sun P, Cabrera ML, Huang CH, Pavlostathis SG. Biodegradation of veterinary ionophore antibiotics in broiler litter and soil microcosms. Technology. 2014;48:2724–31.
Panyod S, Wu WK, Ho CT, Lu KH, Liu CT, Chu YL, et al. Diet supplementation with allicin protects against alcoholic fatty liver disease in mice by improving anti-inflammation and antioxidative functions. J Agric Food Chem. 2016;64:7104–13.
Chen G-Q, Lu F-P, Du L-X. Natamycin production by Streptomyces gilvosporeus based on statistical optimization. J Agric Food Chem. 2008;56:5057–61.
Kassem MA, Esmat S, Bendas ER, El-Komy MH. Efficacy of topical griseofulvin in treatment of tinea corporis. Mycoses. 2006;49:232–35.
Täuber A, Müller-Goymann CC. Comparison of the antifungal efficacy of terbinafine hydrochloride and ciclopirox olamine-containing formulations against the dermatophyte trichophyton rubrum in an infected nail plate model. Mol Pharm. 2014;11:1991–6.
Song L, Jiang X, Fau -, Wang L, Wang L. Determination of butenafine hydrochloride in human plasma by liquid chromatography electrospray ionization-mass spectrometry following its topical administration in human subjects. J Chromatogr B Anal Technol Biomed Life Sci. 2011;879:3658–62.
Rana A, Roohi N, Khan MA. Fascioliasis in cattle-a review. J Anim Plant Sci. 2014;24:668–75.
Kwon D, Park E, Sesaki H, Kang SJ. Carbonyl cyanide 3-chlorophenylhydrazone (CCCP) suppresses STING-mediated DNA sensing pathway through inducing mitochondrial fission. Biochem Biophys Res Commun. 2017;493:737–43.
Moroney J, Fu S, Moulder S, Falchook G, Helgason T, Levenback C, et al. Phase I study of the antiangiogenic antibody Bevacizumab and the mTOR/Hypoxia-inducible factor inhibitor temsirolimus combined with liposomal doxorubicin: tolerance and biological activity. Clin Cancer Res: Off J Am Assoc Cancer Res. 2012;18:5796–805.
Moroney J, Schlumbrecht M, Helgason T, Coleman R, Moulder S, Naing A, et al. A Phase I trial of Liposomal Doxorubicin, Bevacizumab, and Temsirolimus in patients with advanced gynecologic and breast malignancies. Clin Cancer Res: Off J Am Assoc Cancer Res. 2011;17:6840–6.
Ferreira D, Martins L, Fernandes A, Martins M. A tale of two ends: repurposing metallic compounds from anti-tumour agents to effective antibacterial activity. Antibiotics. 2020;9:321.
Gur D, Chitlaru T, Mamroud E, Zauberman A. Screening of an FDA-approved library for novel drugs against Y. pestis. Antibiotics. 2021;10:40.
Hanane Y, Ranque S, Cassagne C, Rolain J-M, Bittar F. Identification of repositionable drugs with novel antimycotic activity by screening Prestwick Chemical Library against emerging invasive molds. J Glob Antimicrob Resist 2020;21:314–7.
Serafin M, Hörner R. Drug repositioning, a new alternative in infectious diseases. Braz J Infect Dis. 2018;22:252–56.
Yan Y-F, Yang C-J, Shang X-F, Zhao Z-M, Liu Y-Q, Zhou R, et al. Bioassay-guided isolation of two antifungal compounds from Magnolia officinalis, and the mechanism of action of honokiol. Pesticide Biochem Physiol. 2020;170:104705.
Zhao W, An J-X, Hu Y-M, Li A-P, Zhang S-Y, Zhang B-Q, et al. Tavaborole-induced inhibition of the Aminoacyl-tRNA biosynthesis pathway against botrytis cinerea contributes to disease control and fruit quality preservation. J Agric Food Chem. 2022;70:12297–309.
Li A-P, He Y-H, Zhang S-Y, Shi Y-P. Antibacterial activity and action mechanism of flavonoids against phytopathogenic bacteria. Pesticide Biochem Physiol. 2022;188:105221.
Zhang S, Cai J, Xie Y, Zhang X, Yang X, Lin S, et al. Anti-Phytophthora activity of halofuginone and the corresponding mode of action. J Agric Food Chem. 2022;70:12364–71.
Chang C-W, Fosso Yatchang M, Kawasaki Y, Shrestha S, Bensaci M, Wang J, et al. Antibacterial to antifungal conversion of neamine aminoglycosides through alkyl modification. Strategy for reviving old drugs into agrofungicides. J Antibiot. 2010;63:667–72.
Garcia M, Chua S, Low Y-S, Lee Y-T, Agnew-Francis K, Wang J-G, et al. Commercial AHAS-inhibiting herbicides are promising drug leads for the treatment of human fungal pathogenic infections. Proc Natl Acad Sci. 2018;115:E9649–58.
Acknowledgements
This work was supported financially by the National Natural Science Foundation of China (22177043, 21877056) and The Natural Science Foundation of Gansu Province (20JR5RA311); Support was also supplied by the Key Program for international S&T cooperation projects of China Gansu Province (18YF1WA115).
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An, JX., Ma, Y., Zhao, WB. et al. Drug repurposing strategy II: from approved drugs to agri-fungicide leads. J Antibiot 76, 131–182 (2023). https://doi.org/10.1038/s41429-023-00594-2
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DOI: https://doi.org/10.1038/s41429-023-00594-2
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