Alkaloids from stems of Esenbeckia leiocarpa Engl. (Rutaceae) as potential treatment for Alzheimer disease.

Esenbeckia leiocarpa Engl. (Rutaceae), popularly known as guarantã, goiabeira, is a native tree from Brazil. Bioactivity-guided fractionation of the ethanol stems extract afforded the isolation of six alkaloids: leiokinine A, leptomerine, kokusaginine, skimmianine, maculine and flindersiamine.

Trypanosoma cruzi surface molecule gp90 downregulates invasion of gastric mucosal epithelium in orally infected mice.

Experiments were performed to elucidate why Trypanosoma cruzi isolates 573 and 587 differ widely in their efficiency to infect gastric mucosal epithelium when administered orally to mice. These isolates have the same surface profile and a similar capacity to enter host cells in vitro. Metacyclic forms of isolates 573 and 587 and the control CL isolate expressed similar levels of gp82, which is a cell invasion-promoting molecule.