Design, synthesis, and fungicidal activities of novel piperazine thiazole derivatives containing oxime ether or oxime ester moieties

Abstract

BACKGROUND: To study the effect of changing the piperidine ring of oxathiapiprolin on the fungicidal activity, we designed and synthesized novel piperazine thiazole derivatives containing oxime ether or oxime ester moieties, and studied their fungicidal activities against Phytophthora capsici in vitro.RESULTS: These derivatives showed moderate to good fungicidal activities against Phytophthora capsici, two oxime ether derivatives showed higher fungicidal activity in vitro than dimethomorph (EC 50 = 0.1331 ∼g mL −1 ) and comparable to oxathiapiprolin (EC 50 = 0.0042 ∼g mL −1 ). Oxime ester derivatives showed significantly reduced activities compared with oxime ether derivatives. Most of these derivatives showed broad-spectrum fungicidal activity against the other eight kinds of fungi. Moreover, four derivatives exhibited good antifungal activities in vivo against Phytophthora capsici, Pseudoperonospora cubensis, and Phytophthora infestans. The hyphae morphology study showed that compound 10d might cause mycelial abnormalities of Phytophthora capsici. CONCLUSION:The activity of 10b against Phytophthora infestans was better than that of mandipropamid, and compound 10d exhibited higher fungicidal activities against Pseudoperonospora cubensis and Phytophthora infestans than mandipropamid. These two derivatives emerged as promising candidates for antifungal drugs.

Oxime Derivatives: A Valid Pharmacophore in Medicinal Chemistry

“…Oximes are attractive functional frameworks with widespread applications not only in synthesis but also in medicine and materials chemistry. [4] These compounds have been effectively converted into amides [5] and amines, [6] including nitroalkanes, 1,3-oxazoles, [7] -thiazoles and -diazoles, hydroxylamines, [8] and hydroxylamine O-ethers, nitroalkanes. [9] Typically, oxime anions in solution behave amorphously, but they can function as weak bases (pK b = 12) and weak acids (pK a = 11).…”

Design, Synthesis, and Biological Evaluation of Novel Derivatives of the Marine Natural Product Laurene

“…23 Fungicidal Mechanism Research. Scanning electron microscopy (SEM) observations on the hyphae of Physalospora piricola were conducted according to the reported method; 24 the detailed methods can be seen in the Supporting Information.…”

Flavonol Derivatives Containing a Quinazolinone Moiety: Design, Synthesis, and Antiviral Activity

“…[23][24] Flavonols and quinazolinones have a wide range of biological activities, the active splicing method has been widely used in the development of new pesticides. [25][26][27] Therefore, 20 flavonol derivatives containing quinazolinone were designed, synthesized and evaluated for their antiviral activity by using the natural product flavonol as a lead compound and introducing quinazolinone moiety (Figure 1). Bioassays demonstrated that K5 exhibited the better antiviral activity compared with that of NNM.…”