Design, synthesis and biological evaluation of novel evodiamine and rutaecarpine derivatives against phytopathogenic fungi.

Evodiamine and rutaecarpine are two alkaloids isolated from traditional Chinese herbal medicine Evodia rutaecarpa, which have been reported to have various biological activities in past decades. To explore the potential applications for evodiamine and rutaecarpine alkaloids and their derivatives, various kinds of evodiamine and rutaecarpine derivatives were designed and synthesized. Their antifungal profile against six phytopathogenic fungi Rhizoctonia solani, Botrytis cinerea, Fusarium graminearum, Fusarium oxysporum, Sclerotinia sclerotiorum, and Magnaporthe oryzae were evaluated for the first time. Furthermore, a series of modified imidazole derivatives of rutaecarpine were synthesized to investigate the structure-activity relationship. The results of antifungal activities in vitro showed that imidazole derivative of rutaecarpine A1 exhibited broad-spectrum inhibitory activities against R. solani, B. cinerea, F. oxysporum, S. sclerotiorum, M. oryzae and F. graminearum with EC50 values of 1.97, 5.97, 12.72, 2.87 and 16.58 µg/mL, respectively. Preliminary mechanistic studies showed that compound A1 might cause mycelial abnormalities of S. sclerotiorum, mitochondrial distortion and swelling, and inhibition of sclerotia formation and germination. Moreover, the curative effects of compound A1 were 94.7%, 81.5%, 80.8%, 65.0% at 400, 200, 100, 50 µg/mL in vivo experiments, which was far more effective than the positive control azoxystrobin. Significantly, no phytotoxicity of compound A1 on oilseed rape leaves was observed obviously even at a high concentration of 400 µg/mL. Therefore, compound A1 is expected to be a novel leading structure for the development of new antifungal agents.

Effects of different concentrations of amino acids in the culture medium on preimplantation mouse embryo development in vitro.

OBJECTIVE: To evaluate the effects of amino acids (AA) on the development of in vitro cultured preimplantation embryos of Kunming mice, and define the optimal AA concentration for embryo culture. METHODS: Totally 630 zygotes were collected from the oviducts of superovulated female Kunming mice, which were cultured in protein-free potassium simplex optimized medium (mKSOM) supplemented with Eagle's essential amino acids and Eagle's non-essential amino acids of different concentrations (mKSOM, mKSOM+1/16AA, mKSOM+1/8AA, mKSOM+1/4AA, mKSOM+1/2AA, mKSOM+AA, and mKSOM+2AA). RESULTS: The embryos cultured with the amino acids showed higher development rate to both 8-cell embryo stage and blastocyst stage than those cultured without amino acids. The correlation of amino acid concentration with 8-cell and blastocyst development rates conformed to the cubic model, with the highest development rate to both of the two stages observed at half of the amino acid concentration. CONCLUSION: Amino acids can promote the development of preimplantation Kunming mouse embryos, but excessively high concentration of amino acids impair embryo development possibly because of metabolic and osmotic pressure changes of the embryos as well as toxicity of ammonium resulting from the metabolism of amino acids.