Search results for "derivati"
showing 10 items of 1360 documents
Mechanistic investigation of food effect on disintegration and dissolution of BCS class III compound solid formulations: the importance of viscosity
2012
A negative food effect, i.e. a decrease in bioavailability upon the co-administration of compounds together with food, has been attributed particularly with high solubility/low permeability compounds (BCS class III). Different mechanisms have been proposed including intestinal dilution leading to a lower concentration gradient across the intestinal wall as well as binding of the active pharmaceutical ingredient to food components in the intestine and thereby decreasing the fraction of the dose available for absorption. These mechanisms refer primarily to the compound and not to the dosage form. An increase in viscosity of the dissolution fluid will in particular affect the absorption of BCS…
Biological activity of flucycloxuron, a novel benzoylphenylurea derivative, onTenebrio molitor: comparison with diflubenzuron and triflumuron
1993
Flucycloxuron, a novel benzoylphenylurea (BPU) derivative, exhibited insecticidal activity when injected into newly ecdysed pupae ofTenebrio molitor. Mortality occurs because of defective adult ecdysis. Treatment caused a reduction in both cuticle thickness and incorporation of14C-labelled precursor into chitin, although it had no significant effect on the protein synthesis. The potencies of other BPU compounds as inhibitors of chitin biosynthesis have been examined and results showed that diflubenzuron was less effective than either flucycloxuron or triflumuron.
Comparative Structural Studies of 4-Diazopyrazole Derivatives by X-Ray Diffraction and Theoretical Investigation
2005
The X-Ray crystal and molecular structures of the 4-pyrazol derivatives 3-methyl-4-diazo-5-benzamido-1H-pyrazole (4) and 3-benzamido-5-methyl-1H-pyrazole (3) have been determined. A dimeric structure has been found for the first and polymeric for the second. A comparison of 4 with 1,3-dimethyl-4-diazo-5-benzamido-lH-pyrazole (2) shows differences in the geometrical parameters of the pyrazole ring due to electron delocalization in 2 consequent to the nitrogen negative charge in the latter. Theoretical investigation at the density functional theory (DFT) level shows difference in the molecular electronic distribution of 2 and 4, in agreement with the structural parameters and the IR stretchin…
Designing fluorous domains. Synthesis of a series of pyridinium salts bearing a perfluoroalkylated azole moiety
2006
The synthesis of a series of N-methylpyridinium salts bearing a perfluoroalkylated 1,2,4-oxadiazole or 1,2,4-triazole moiety is reported. X-Ray structures of representative perfluoroalkyl-triazolylpyridine (15) and methyl- pyridinium iodide salt (5a) are reported. Their crystal packing clearly shows segregation between the aromatic and parallel double layer fluorinated regions.
The Cytotoxic Properties of Natural Coumarins Isolated from Roots ofFerulago campestris(Apiaceae) and of Synthetic Ester Derivatives of Aegelinol
2009
Grandivittin (1), agasyllin (2), aegelinol benzoate (3) and felamidin (20), four natural coumarins isolated from Ferulago campestris, and several synthetic ester derivatives of aegelinol (4) were tested against four tumor cell lines. Some of them were shown to be marginally cytotoxic against the A549 lung cancer cell line.
Fluorinated Heterocyclic Compounds. A Photochemical Approach to a Synthesis of Polyfluoroaryl-1,2,4-triazoles.
2005
The reaction of some fluorinated 1,2,4-oxadiazoles in the presence of methylamine or propylamine has been investigated. The irradiation in methanol or acetonitrile leads with acceptable yields to the corresponding fluorinated 1- methyl- or 1-propyl-1,2,4-triazole.
�ber die Wirkung von Strophanthidin-3-bromacetat am Papillarmuskel des Meerschweinchens
1971
In experiments on isolated, electrically stimulated papillary muscles or auricles of guinea pig hearts some characteristics of the inotropic action of strophanthidin-3-bromaocetate (SBA), a derivative of k-strophanthidin which is supposed to be an irreversible inhibitor of the (Na+-K+)-activated ATPase, were studied and compared with the behaviour of k-strophanthidin and digitoxin.
Posaconazole concentrations in the central nervous system
2008
more susceptible to the killing activity of caspofungin. This study is the first comparing caspofungin killing activity against the closely related species C. parapsilosis, C. orthopsilosis and C. metapsilosis. Killing curves, regardless of the medium used, showed a decreasing order of susceptibility to caspofungin: C. metapsilosis . C. orthopsilosis . C. parapsilosis. Based on high echinocandin MICs for C. parapsilosis sensu stricto, in the case of isolates identified as C. parapsilosis sensu lato low MICs of echinocandins may be regarded as an indicator that an isolate is in fact C. orthopsilosis or C. metapsilosis; in the case of isolates with low echinocandin MICs, DNA-based identificat…
Synthetic derivatives of aromatic abietane diterpenoids and their biological activities
2014
Naturally occurring aromatic abietane diterpenoids (dehydroabietanes) exhibit a wide range of biological activities. A number of synthetic studies aimed at modifying the abietane skeleton in order to obtain new potential chemotherapeutic agents have been reported. In this study, the biological activities of synthetic derivatives of aromatic abietane diterpenoids are reviewed.
Ircinal E, a New Manzamine Derivative from the Indonesian Marine Sponge Acanthostrongylophora ingens
2015
Chemical investigation of the MeOH extract of the sponge Acanthostrongylophora ingens afforded the new manzamine derivative ircinal E (1), in addition to six known metabolites (2–7). The structure of the new compound was unequivocally elucidated using one- and two-dimensional NMR spectroscopy, as well as high-resolution mass spectrometry. Compounds 1–6 exhibited strong to moderate cytotoxicity against the murine lymphoma L5178Y cell line with IC50 values ranging from 2.8 to 21.7 μM.