A new β-hydroxy-γ-methyl-γ-lactone bistetrahydrofuranic acetogenin, tucumanin, with the infrequent symmetrical threo/trans/threo/trans/ threo relative configuration at the tetrahydrofuran rings was isolated from Annona ...

The drimane sesquiterpenoids drimenin, cinnamolide, dendocarbin A, and polygodial were purified from the Canelo tree (Drimys winteri) and chemically characterized by spectroscopic methods. The pharmacological activity of ...

Accidents with poisonous snakes are a major health hazard in tropical countries. Bothrops genus is responsible for more than 70 % of snakebites in Brazil. Immunotherapy is the only recommended specific treatment against ...

The analgesic effects of (+)- and (-)-amphetamine (AMPH), (+/-)-p-methoxyamphetamine (MA), (+/-)-N-methyl-p-methoxyamphetamine (MMA) and (+/-)-N-ethyl-p-methoxyamphetamine (EMA) were compared using two different algesimetric ...

The effect of various natural and synthetic steroids on the function of the nicotinic acetylcholine receptor (AChR) was studied at the single-channel level. AChR channel kinetics was affected by some substitutions in the ...

The enzyme 4-hydroxyphenylpyruvate dioxygenase catalyzes the second step in the tyrosine degradation pathway. In mammals, this enzyme is the molecular target of drugs used for the treatment of metabolic disorders associated ...

Although in vitro transport/inhibition studies are commonly performed on impure drug candidates to screen for pharmacokinetic properties in early development, quantitative guidelines concerning acceptable impurity levels ...

Two microcystins, MC-LR and [D-Leu1]MC-LR, present in La Plata Basin blooms, are differentiated by substitution of D-Alanine for D-Leucine at position 1. Our objective was to evaluate acute toxicity of [D-Leu1]MC-LR and ...

The in vitra and ex viva monoamine oxidase (MAO) inhibitory effects of (±)4-dimethylaminoa- methyl-phenethylamine (4-DMAA) and (± )4-methylamino-a-methyl-phenethylamine (4-MAA) were reassessed, in comparison with the ...