Search results for "Biological activity"
showing 10 items of 465 documents
Analgesic Activity and Effects on Isolated Smooth Muscle of Different Fractions of Hexane Extract fromAraujia sericifera Brot
1996
The present study analyses the analgesic activity and action on in vitro motility of methanol soluble and methanol insoluble fractions obtained from the hexane extract of fruits from Araujia sericifera. The methanol fraction did not show any pharmacological activity on the different tests evaluated. However, the insoluble methanol fraction exhibited an interesting analgesic effect in models of chemical and thermal stimulus and it reduced the E max induced by histamine in vitro on guinea-pig ileum. This extract lacked any central depressor activity since it did not modify the number of mouse movements in the activity cage.
CNS depressant effects, anti-inflammatory activity and anti-cholinergic actions ofSantolina chamaecyparissus extracts
1988
The pharmacological activity of several extracts together with the lyophilized infusion of S. chamaecyparissus ssp. squarrosa were investigated. The lethal dose 50% (LD50), effect on animal metabolism, mechanical and thermic analgesia and spontaneous, anti-inflammatory, and anti-ulcer activity have been determined. Studies on isolated organs (rat duodenum and rat uterus) were also carried out. The hexanic and chloroformic extracts were potent antagonists of the thermic analgesia test; the former extract was also active in the mechanical analgesia test. The chloroformic extract and, to a lesser extent, the ethyl acetate extract and lyophilized infusion demonstrated noteworthy activity as ant…
Nostotrebin 6 Related Cyclopentenediones and δ-Lactones with Broad Activity Spectrum Isolated from the Cultivation Medium of the Cyanobacterium Nosto…
2020
Cyanobacteria are an interesting source of biologically active natural products, especially chemically diverse and potent protease inhibitors. On our search for inhibitors of the trypanosomal cysteine protease rhodesain, we identified the homodimeric cyclopentenedione (CPD) nostotrebin 6 (1) and new related monomeric, dimeric, and higher oligomeric compounds as the active substances in the medium extract of Nostoc sp. CBT1153. The oligomeric compounds are composed of two core monomeric structures, a trisubstituted CPD or a trisubstituted unsaturated δ-lactone. Nostotrebin 6 thus far has been the only known cyanobacterial CPD. It has been found to be active in a broad variety of assays, indi…
Gas chromatography/mass spectrometry of catechol estrogens
1992
Abstract Catecholestrogens (CCEs), namely 2- or 4-hydroxyestradiol and hydroxyestrone, are highly polar, reactive, and extremely labile estrogen metabolites in many experimental conditions. For these reasons, indirect assay methods mainly have been used. Some experimental evidence suggests that CCEs are synthesized and biologically active mostly in target cells. At this level, unfortunately, the indirect assays cannot be used. We present a method of gas Chromatographic/mass spectral (GC/MS) analysis for the identification of individual CCEs; the major fragmentation ions of authentic estrogen standards as trimethylsilylether derivatives, and the MS patterns of the major CCEs, namely, 2-hydro…
Discovery of new antimalarial compounds by use of molecular connectivity techniques.
1999
Abstract Molecular connectivity has been applied to the search for new compounds with antimalarial activity. Linear discriminant analysis and connectivity functions were used to select several potentially suitable drugs which were tested for antimalarial properties by use of an in-vitro micro test which estimates parasite growth by measurement of incorporation of [3H]hypoxanthine. Hexetidine stands out among the compounds selected. Activity assays were performed with Plasmodium falciparum passou and 3CD7 strains, for which the IC50 values (doses resulting in 50% inhibition) were 320 and 400 ng mL−1 respectively. These results are comparable with those obtained for quinine chlorhydrate (IC50…
Structure and Biological Activity of the Furan-Diterpenoids from the Genera Leonotis and Leonurus
2007
The present review, covering the literature up to 2006, reports the chemistry and the biological activities of the diterpenoids occurring in the aerial parts of species belonging to the genera Leonotis and Leonurus, family Lamiaceae.
A density functional study of flavonoid compounds with anti-HIV activity.
2005
Abstract Quantum chemical calculations at the DFT/B3LYP theory level, with the 6-31G* basis set, was employed to calculate a set of molecular properties of 26 flavonoid compounds with anti-HIV activity. The correlation between biological activity and structural properties was obtained by using the multiple linear regression method. The model obtained showed not only statistical significance but also predictive ability. We demonstrate in this paper that the anti-HIV activity of compounds can be related with the molecular hydrophobicity (ClogP), the electronegativity ( χ ) and the charges on some key atoms, while that the toxicity can be related with the electronic affinities (EA), ClogP and …
In vitro studies of methanol and dichloromethanol extracts ofJuniperus oxycedrus L.
1997
The present study evaluated the effect of methanol and dichloromethanol extracts obtained from the leaves and stems of Juniperus oxycedrus against neurotransmitter-induced contraction in different isolated tissues of rats and guinea-pigs. Diverse concentrations of these extracts inhibit the concentration curve response to histamine, serotonin and acetylcholine. These results contribute to explaining the use of this plant in folk medicine. © 1997 John Wiley & Sons, Ltd.
A review of the pharmacology and toxicology ofAstragalus
1997
Some Astragalus species are used as forage for livestock and wild animals. Many species are used in folk medicine for their hepatoprotective, antioxidative, immunostimulant, and antiviral properties, whereas others are toxic, and in many cases the toxic principles can pass to humans through milk and meat. Three groups of chemicals have been described as pharmacologically active principles: polysaccharides, saponins and phenolics. In addition, three kinds of toxic principles have been reported: indolizidine alkaloids, aliphatic nitro compounds and selenium. © 1997 John Wiley & Sons, Ltd.
Study of the antioedema activity of some seaweed and sponge extracts from the mediterranean coast in mice
1993
Chloroform and methanol extracts of ten marine species, seven seaweeds and three sponges, have been studied for possible, antioedema activities. The extracts were administered either topically or orally on TPA-induced mouse ear oedema and on carrageenan mouse paw oedema, respectively. The most interesting seaweed extracts were found to be from Corallina elongata, Galaxaura oblongata, Laurencia obtusa and Udotea petiolata, where both extracts of each species induced a large antioedema effect in both models employed. None of the sponges assayed demonstrated antiinflammatory effects on carrageenan mouse paw oedema, however, some extracts elicited an inhibition of the oedema developed by TPA.