Antimicrobial triterpenoids from Licania heteromorpha.

Six triterpenoids having a lupane and oleane skeleton were isolated from the leaves and young branches of Licania heteromorpha Bentham var. heteromorpha and were identified as: betulinic acid 1, alphitolic acid 2, 3 beta-O-trans-p-coumaroyl alphitolic acid 3, 3 beta-O-cis-p-coumaroyl alphitolic acid 4, 3 beta-O-trans-p-coumaroyl maslinic acid 5, 3 beta-O-cis-p-coumaroyl maslinic acid 6. The antimicrobial activity of these compounds was evaluated in vitro on clinically isolated microorganisms employing a microdilution method. Compounds 2, 3, 5, and 6 showed antimicrobial activity on Gram-positive bacteria and yeasts, whereas none of the six triterpenoids were active against Gram-negative organisms.

A sensitive assay for studying dopaminergic activity in cultures of rat pituitary cells.

The dopaminergic and antidopaminergic activity of drugs is frequently assayed in pituitary cell cultures. Here we describe a modified version of the assay based on the use of pituitary cells from prepubertal female rats. Under our experimental conditions (50,000 cells well-1, 2-day culture and 2-h drug-exposure) the assay yielded high selectivity and sensitivity for drug dopaminergic activity. D2 agonistic activity of bromocriptine could be observed at a concentration as low as 10(-15) M, the antagonistic activity of haloperidol at 10(-16) M. The assay also proved reproducible and simple enough for routine screening of dopaminergic activity. The assay enabled dopaminergic agonist and antagonist activity to be revealed at very low drug concentrations. The high sensitivity of the assay could be of advantage in studying dopaminergic activity in samples containing active substances present at low concentrations or for disclosing the activity of substances with low dopaminergic potency.

[The biological and electrophysiological parameters in the rat chronically treated with Lobelia inflata L]. / Parametri biologici ed elettrofisiologici nel ratto trattato cronicamente con Lobelia inflata L.

In this paper we have studied the rat under chronic treatment with Lobeline sulphate ip. For a three week period we have recorded, once a week, weight, rectal temperature, tail-flick, motor coordination and general activity in a one-arm radial maze and in a Boissier-Simon table. At the end of the third week surface (SEEG) and deep (DEEG) EEG were recorded both from treated and control animals. The findings are: 1) no changes was observed in weight, rectal temperature, tail-flick and motor coordination; 2) the treated rats showed an increased general activity both in a one-arm radial maze and in the Boissier-Simon table; 3) the EEG effects were analyzed and quantified, by means of Fast Fourier transform, as total power and as power in preselected bands of frequency. The lobeline sulphate seems to produce both in SEEG and hippocampus a shift toward low frequencies and in amygdala a drift toward high frequencies.