Chemical studies on monoterpenoid indole alkaloids from medicinal plant resources Gelsemium and Ophiorrhiza

A polyhedral approach for understanding flavonoid biosynthesis in Arabidopsis

The sequencing of the entire genome of model plants has made it possible to use these plants for producing metabolites that are beneficial to humans. Plants produce a large number of metabolites, which are potentially valuable sources of novel pharmaceutically active agents that benefit human health. The industrial use of these beneficial metabolites from plants, known as secondary metabolites or specialized metabolites, necessitates the systematic understanding of the biosynthetic mechanisms from the genetic to the metabolic level. Here, we review the recent developments on flavonoid biosynthesis in Arabidopsis thaliana (Arabidopsis) as a model plant. These developments have been made in the fields of metabolomics, transcriptomics, natural products chemistry, genetics and biochemistry. We focused on natural products chemistry in this polyhedral approach, which proved to be indispensable for elucidating the secondary metabolism in not only Arabidopsis but also other model-like and crop plants.

Poisoning in goats by Aspidosperma pyrifolium Mart.: biological and cytotoxic effects

Spontaneous cases of poisoning by Aspidosperma pyrifolium, the toxicity to rats and in vitro cytotoxicity were evaluated. On all spontaneous cases studied, ingestion of the plant and cases of abortion occurred exclusively in goats. The majority of the cases of abortion occurred during the early dry season and the early rainy season, and experienced goats were less likely to be affected than naïve goats. Pregnant Wistar rats dosed with A. pyrifolium extract on the 15th gestational day or from the 15th to the 17th gestational day presented reduction of fetal weight and strong evidence of maternal toxicity was found. Female rats injected A. pyrifolium extract intraperitoneally presented motor disturbances and death; male rats were more resistant than females. Xylazine, atropine and diazepam administration did not prevent the effects of toxicity. Evaluation of the osmotic fragility of red blood cells was performed with the plant extract at different concentrations. In addition, 1-day-old larvae of Artemia salina were incubated with different concentrations of the extract. It was found that the extract of A. pyrifolium promoted hemolysis and was lethal to A. salina. These in vivo and in vitro assays may be useful as adjunct tests for further studies with this plant.

Rhazinilam and quebrachamine derivatives from Yunnan Kopsia arborea

Three new rhazinilam-derived alkaloids, kopsiyunnanines C1, C2, and C3, and a new quebrachamine-type alkaloid, kopsiyunnanine D, which possess an unusual methoxymethyl or ethoxymethyl function, were isolated from the aerial parts of Yunnan Kopsia arborea. This is the first report of the presence of these functions in natural alkaloids. The structures and absolute configurations of the alkaloids were determined by spectroscopic methods and confirmed by semisynthesis.