Novel Pyridyl-Oxazole Carboxamides: Toxicity Assay Determination in Fungi and Zebrafish Embryos.

Eight novel pyridyl-oxazole carboxamides were evaluated against fungi and displayed good fungicidal activities against Botrytis cinereal and Rhizoctonia solani. Preliminary bioassay results indicated that at 100 mg/L, compounds 6a-6e, 6g and 6h exhibited 100% fungicidal activities against Botrytis cinerea, and the compound 6b to Rhizoctonia solani at 100%. Then, the zebrafish embryo acute toxicity test was performed to assess the toxicity of 6b and 6c. A series of malformations appeared, when the zebrafish embryos were exposed to 6b and 6c, such as delayed yolk sac resorption, significant shortening of body length, pericardial edema, bending spine, lack of melanin, heart hemorrhage, head hemorrhage, delayed swim sac development, yolk malformation and head malformation. In addition, the acute toxicity of 6b to zebrafish embryo is 4.878 mg/L, and 6c is 6.257 mg/L.

1,2,4-Oxadiazole-Based Bio-Isosteres of Benzamides: Synthesis, Biological Activity and Toxicity to Zebrafish Embryo.

To discover new compounds with broad spectrum and high activity, we designed a series of novel benzamides containing 1,2,4-oxadiazole moiety by bioisosterism, and 28 benzamides derivatives with antifungal activity were synthesized. These compounds were evaluated against four fungi: Botrytis cinereal, FusaHum graminearum, Marssonina mali, and Thanatephorus cucumeris. The results indicated that most of the compounds displayed good fungicidal activities, especially against Botrytis cinereal. For example, 10a (84.4%), 10d (83.6%), 10e (83.3%), 10f (83.1%), 10i (83.3%), and 10l (83.6%) were better than pyraclostrobin (81.4%) at 100 mg/L. In addition, the acute toxicity of 10f to zebrafish embryo was 20.58 mg/L, which was classified as a low-toxicity compound.

Synthesis and Biological Activity of Benzamides Substituted with Pyridine-Linked 1,2,4-Oxadiazole.

To find pesticidal lead compounds with high activity, a series of novel benzamides substituted with pyridine-linked 1,2,4-oxadiazole were designed by bioisosterism, and synthesized easily via esterification, cyanation, cyclization and aminolysis reactions. The structures of the target compounds were confirmed by 1H-NMR, 13C-NMR and HRMS. The preliminary bioassay showed that most compounds had good larvicidal activities against mosquito larvae at 10 mg/L, especially compound 7a, with a larvicidal activity as high as 100%, and even at 1 mg/L was still 40%; at 50 mg/L, all the target compounds showed good fungicidal activities against the eight tested fungi. Moreover, compound 7h exhibited better inhibitory activity (90.5%) than fluxapyroxad (63.6%) against Botrytis cinereal. Therefore, this type of compound can be further studied.

Studies on quality standard of Yifu ointment / 中国中药杂志

<p><b>OBJECTIVE</b>To develop a method for the determination of Chonglou saponin I and Chonglou saponin II in Yifu ointment.</p><p><b>METHOD</b>The chromatographic separation was performed on Hypersil ODS2 C18 column (4.6 mm x 150 mm, 5 microm) and IBBM-612111 ODS C18 guard column. Acetonitrile-0.02% phosphoric (43:57) as mobile phase. The flow rate was 1 mL min(-1) and column temperature was set at 40 degrees C. The UV detection wavelength was set 203 nm.</p><p><b>RESULT</b>Chonglou saponin I showed a good linear relationship at a range of 0.1024-3.2 microg, r =0.9998, the average recovery was 97.4%, and RSD was 1.8% (n = 6); Chonglou saponin II showed a good linear relationship at a range of 0.064-2.0 microg, r = 0.9999, the average recovery was 101.4%, and RSD was 1.0% (n =6).</p><p><b>CONCLUSION</b>The method is accurate with the good reproducibility and can be used for the quality control of Yifu Ointment.</p>