Synthesis and Antibacterial Evaluation of New Sulfone Derivatives Containing 2-Aroxymethyl-1,3,4-Oxadiazole/Thiadiazole Moiety

Abstract

Sulfones are one of the most important classes of agricultural fungicides. To discover new lead compounds with high antibacterial activity, a series of new sulfone derivatives were designed and synthesized by introducing the aroxymethyl moiety into the scaffold of 1,3,4-oxadiazole/thiadiazole sulfones. Antibacterial activities against three phytopathogens (Xanthomonas oryzae pv. oryzae, Ralstonia solanacearum, Xanthomonas axonopodis pv. citri.) were assayed in vitro. As compared to the control of commercial fungicides and some reported sulfone fungicides, seven compounds 5I-1–5I-7 exerted remarkably higher activities with EC50 values ranging from 0.45–1.86 μg/mL against X. oryzae and 1.97–20.15 μg/mL against R. solanacearum. Exhilaratingly, 5I-1, 5I-2 and 5I-4 displayed significant in vivo activity against X. oryzae with protective effect of 90.4%, 77.7%, and 81.1% at 200 μg/mL, respectively, much higher than that exhibited by Bismerthiazol (25.6%) and Thiadiazole-copper (32.0%). And the differential phytotoxicity of active derivatives was preliminarily checked. The results demonstrated that derivative of 2-aroxymethyl-1,3,4-oxadiazole/thiadiazole sulfone can serve as potential alternative bactericides for the management of plant bacterial diseases.

Novel bisthioether derivatives containing a 1,3,4‐oxadiazole moiety: design, synthesis, antibacterial and nematocidal activities

“…51 When the thioether group at the 2-position of 1,3,4-oxadiazole ring was replaced with sulfone group, and when the thioether group at the 5-position of 1,3,4-oxadiazole ring was replaced with oxygen ether, phenyl or benzyl group, the in vitro antibacterial activities of the corresponding compounds were lower (phenyl group) or better (oxygen ether and benzyl group) than those of the target compounds. 9,[11][12][13] Therefore, the SAR analysis demonstrated that both thioether groups at the 2,5-positions of 1,3,4-oxadiazole ring play a significant role in the design of the target compounds.…”

“…It has recently been shown that the 1,3,4-oxadiazole ring, one of the most important and well-known heterocyclic nuclei, exhibits a wide variety of pesticidal biological activities, including antibacterial, [7][8][9][10][11][12][13] antifungal, [14][15][16][17][18][19][20][21] antiviral, [21][22][23] insecticidal, [24][25][26][27] and herbicidal. 28,29 In addition, in 2005, Guimarães et al demonstrated that introduction of a 1,3,4-oxadiazole ring into target compounds could change their polarity, flexibility and metabolic stability, effectively enhancing their bioactivity.…”

“…1a,b) that had greater antibacterial activity against tomato and tobacco bacterial wilts, rice bacterial leaf blight and leaf streak, and citrus canker compared with traditional commercial bactericides, such as kocide 3000, thiodiazole copper and bismerthiazol. [7][8][9][10][11][12][13][14][15][16][17] Thioether groups are known to be associated with a broad spectrum of pesticidal bioactivities, for example antiviral, 21,[31][32][33][34][35] antibacterial, [36][37][38][39][40][41] antifungal, 21,39,40 insecticidal 41,42 and nematocidal. 43 Over the past few years, study of the synthesis and pesticidal bioactivity of thioether derivatives has attracted considerable attention and some representative examples of thioether derivatives commercialized as pesticides (e.g.…”

In Situ IR‐ATR Study of the Interaction of Nitrogen Heteroaromatic Compounds with HY Zeolites: Experimental and Theoretical Approaches

“…Otherwise, N‐heteroaromatic compounds such as indole are also valorized in the synthesis of fine chemical (pharmaceuticals, agrochemicals, and dyes) . These reactions are conventionally performed over both liquid phase Brønsted acids and Lewis acids .…”

New 1,3,4‐Thiadiazole Derivatives: Synthesis, Characterization, and Antimicrobial Activity

“…Several studies have shown that two or three heterogeneous atoms such as nitrogen and sulfur are expected to have antimicrobial activities . In addition, many 1,3,4‐thiadiazoles are used as fungicides, bactericides, and herbicides in the agricultural field . Acid hydrazides are reactive substances and have been used as useful synthons of various heterocyclic rings with one or several heteroatoms.…”