Bioactivity and structure-activity relationship of cinnamic acid esters and their derivatives as potential antifungal agents for plant protection

Abstract

A series of cinnamic acid esters and their derivatives were synthesized and evaluated for antifungal activities in vitro against four plant pathogenic fungi by using the mycelium growth rate method. Structure−activity relationship was derived also. Almost all of the compounds showed some inhibition activity on each of the fungi at 0.5 mM. Eight compounds showed the higher average activity with average EC50 values of 17.4–28.6 μg/mL for the fungi than kresoxim-methyl, a commercial fungicide standard, and ten compounds were much more active than commercial fungicide standards carbendazim against P. grisea or kresoxim-methyl against both P. grisea and Valsa mali. Compounds C1 and C2 showed the higher activity with average EC50 values of 17.4 and 18.5 μg/mL and great potential for development of new plant antifungal agents. The structure−activity relationship analysis showed that both the substitution pattern of the phenyl ring and the alkyl group in the alcohol moiety significantly influences the activity. There exists complexly comprehensive effect between the substituents on the phenyl ring and the alkyl group in the alcohol moiety on the activity. Thus, cinnamic acid esters showed great potential the development of new antifungal agents for plant protection due to high activity, natural compounds or natural compound framework, simple structure, easy preparation, low-cost and environmentally friendly.

<i>m</i>-Coumaric acid attenuates non-catalytic protein glycosylation in the retinas of diabetic rats

“…Moreover, previous studies have shown the role of HCA derivatives as antifungal agents that can be used for plant protection. 14) Since HCA is present in cereals and many other plants, it is beneficial for human consumption in addition to being toxic to pathogens. Recent investigations have revealed that cinnamic acid derivatives such as ferulic acid (3-methoxy-4-hydroxycinnamic acid) and isoferulic acid (3-hydroxy-4-methoxycinnamic acid) are the most bioactive components present in the rhizomes of Cimicifuga heracleifolia.…”

Cinnamic Acid Analogs as Intervention Catalysts for Overcoming Antifungal Tolerance

“…With regard to electron-donating groups, our results from cinnamic acid analogs were not well aligned with that of “ethyl” cinnamic acid derivatives [ 39 ]. For example, in our study, 4-methoxycinnamic acid ( p -substitution) belongs to the Group 1, possessing the highest antifungal activity ( Table 1 ), while 2- and 3-methoxycinnamic acids ( o - and m -substitution, respectively) belong to Group 3, showing no antifungal activity ( Table 1 ).…”

“…Antifungal activities of various cinnamic acid derivatives have been documented elsewhere [ 37 , 38 , 39 ]. Structure-activity relationship revealed that the substitution design of cinnamic phenyl ring significantly affected antifungal activity [ 39 ].…”

“…Antifungal activities of various cinnamic acid derivatives have been documented elsewhere [ 37 , 38 , 39 ]. Structure-activity relationship revealed that the substitution design of cinnamic phenyl ring significantly affected antifungal activity [ 39 ]. For instance, introducing substituents to the ring structure of “ethyl” cinnamic acid derivatives generally resulted in enhancement of antifungal activity as follows: (1) w/electron-donating groups (hydroxyl, methoxyl): Order of antifungal activity was o -substitution > p -substitution > m -substitution, (2) w/electron-withdrawing groups (halogen atoms, such as chlorine): Highest activity was observed with p -substitution [ 39 ].…”

Natural and Synthetic Derivatives of Hydroxycinnamic Acid Modulating the Pathological Transformation of Amyloidogenic Proteins

“…As previously described, esters and amides of coumaric, ferulic and caffeic acid possess numerous biological activities, e.g., antioxidant [ 82 , 83 , 86 , 89 , 94 , 95 , 96 ], anticancer [ 78 , 87 , 92 ], antibacterial [ 82 , 97 , 98 , 99 ], antifungal [ 100 , 101 , 102 ], antiviral [ 82 , 90 , 103 ], anti-inflammatory [ 104 , 105 , 106 ], and many other activities [ 84 , 107 , 108 ]. The most commonly described health beneficial properties of HCAs and their derivatives is antioxidant activity due to the phenolic hydroxyl group(s) on the main aromatic ring, which possess(es) the ability to react with free radicals and reactive oxygen species forming a resonance-stabilized phenoxyl radical.…”