Design, synthesis and antifungal evaluation of phenylthiazole‐1,3,4‐oxadiazole thione (ketone) derivatives inspired by natural thiasporine A

Abstract

BACKGROUNDPlant pathogenic fungal infections have become a severe threat to the yield and quality of agricultural products, and new green antifungal agents with high efficiency and low toxicity are needed. In this study, a series of thiasporine A derivatives containing phenylthiazole‐1,3,4‐oxadiazole thione (ketone) structures were designed and synthesized, and their antifungal activities against six invasive and highly destructive phytopathogenic fungi were evaluated.RESULTSThe results found that all compounds showed moderate to potent antifungal activity against six phytopathogenic fungi, and most of the E series compounds showed remarkable antifungal activity against Sclerotinia sclerotiorum and Colletotrichum camelliaet. In particular, compounds E1–E5, E7, E8, E13, E14, E17, and E22 showed more significant antifungal activity against S. sclerotiorum, with half‐maximal effective concentration (EC50) values of 0.22, 0.48, 0.56, 0.65, 0.51, 0.39, 0.60, 0.56, 0.60, 0.63, and 0.45 μg mL−1, respectively, which were superior to that of carbendazim (0.70 μg mL−1). Further activity studies showed that compound E1 possessed superior curative activities against S. sclerotiorum in vivo and better inhibitory effects on sclerotia germination and the formation of S. sclerotiorum compared with those of carbendazim.CONCLUSIONSThis study indicates that these thiasporine A derivatives containing phenylthiazole‐1,3,4‐oxadiazole thione structures might be used as antifungal agents against S. sclerotiorum. © 2023 Society of Chemical Industry.

Design, Synthesis, and Antifungal Activity of Some Novel Phenylthiazole Derivatives Containing an Acylhydrazone Moiety

“…Some derivatives showed potent antifungal activities against some phytopathogenic fungi. For example, derivatives e and f showed significant antifungal activities against Sclerotinia sclerotiorum, with EC 50 values of 0.22 µg/mL and 0.39 µg/mL, respectively, which were superior to that of the commercial fungicide carbendazim (0.70 µg/mL) [18]. The above results demonstrated that phenylthiazole is a promising antifungal skeleton for discovering new fungicides.…”

“…Satisfactorily, some novel compounds with potent antifungal activity against M. oryzae and the SAR results were obtained in this study. In our previous study, most phenylthiazole derivatives mainly showed excellent antifungal activities against S. sclerotiorum and S. rolfsii [15,16,18]. Only phenylthiazole derivatives bearing amide moiety showed good antifungal activity against M. oryzae.…”

“…Some pharmacologists have focused on exploring the pharmacological activity of thiasporine A [14]. As part of our ongoing research on structural modification and bioactivity in the agricultural field of heterocyclic compounds found in natural products, a series of thiasporine A derivatives were synthesized, and their biological activities were systematically evaluated [15][16][17][18]. The results indicated that thiasporine A and its derivatives showed a wide range of bioactivities in the agricultural field, such as antifungal, insecticidal, and herbicidal activities [15].…”

Design, Synthesis, Antibacterial, and Antifungal Evaluation of Phenylthiazole Derivatives Containing a 1,3,4-Thiadiazole Thione Moiety

“…In our previous work, we synthesized several series of thiasporine A derivatives with potent antifungal activity and demonstrated that phenylthiazole was a promising antifungal activity skeleton [ 16 ]. Notably, Shi [ 17 ] introduced an 1,3,4-oxadiazole thione into phenylthiazole to synthesize compound E1 ( Figure 1 ), exhibiting the most excellent antifungal activity against S. sclerotiorum with an EC50 value of 0.22 μg/mL, which was superior to that of the commercial fungicide Carbendazim (EC 50 = 0.70 μg/mL). Regrettably, compound E1 did not perform excellent antibacterial activity, but this result provides valuable guidance for carrying out subsequent molecular design.…”

Antifungal Activity and Mechanism of Camphor Derivatives against Rhizoctonia solani: A Promising Alternative Antifungal Agent for Rice Sheath Blight

“…Many methods have been applied to control rice sheath blight, with chemical control such as fungicides being widely utilized as an effective control measure. , Unfortunately, the intensive and continuous utilization of common fungicides increases the risk of resistance development of the pathogen, which severely restricts the application of these fungicides. , Thus, there is an urgent need for high-efficiency, environmentally friendly, and low-toxic fungicides against R. solani. − …”