7 research outputs found
Nicotinohydrazide
The title molÂecule (alternative name: pyridine-3-carbohydrazide; C6H7N3O) was obtained from the reaction of ethyl nicotinate with hydrazine hydrate in methanol. In the amide group, the C—N bond is relatively short, suggesting some degree of electronic delocalization in the molÂecule. The stabilized conformation may be compared with those of isomeric compounds picolinohydrazide (pyridine-2-carbohydrazide) and isonicotinohydrazide (pyridine-4-carbohydrazide). In the title isomer, the pyridine ring forms an angle of 33.79 (9)° with the plane of the non-H atoms of the hydrazide group. This lack of coplanarity between the hydrazide functionality and the pyridine ring is considerably greater than that observed in isonicotinohydrazide (dihedral angle = 17.14°), while picolinohydrazide is almost fully planar. The title isomer forms interÂmolecular N—H⋯O and N—H⋯N hydrogen bonds, which stabilize the crystal structure
Pharmacological and Phytochemical Evaluation of Adiantum cuneatum Growing in Brazil
This work describes the phytochemical analysis and analgesic activity of a non polar fraction obtained from Adiantum cuneatum grown in Brazil. The results showed that the hexane fraction as well as two pure compounds, identified as filicene (1) and filicenal (2), given intraperitoneally, exhibited potent analgesic activity when evaluated in two models of pain in mice, writhing test and formalin-induced pain. Compound 1 presented a calculated ID50 value of 19.5 μmol/kg body weight, when evaluated in writhing test, being about 7-fold more active than some reference drugs, like as acetyl salicylic acid and acetaminophen. It also inhibited both phases (neurogenic and inflammatory) of the formalin test at 10 mg/kg (24 μmol/kg). The chemical composition of the plant grown in Brazil is similar to that grown in other countries. The results confirm and justify the popular use of this plant for the treatment of dolorous processes
Generation of a chiral giant micelle
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq)Over the past few years, chiral supramolecular assemblies have been successfully used for recognition, sensing and enantioselective transformations. Several approaches are available to control chirality of discrete assemblies (e.g., cages and capsules), but few are efficient in assuring chirality for micellar aggregates. Optically active amino acid-derived surfactants are commonly used to generate chiral spherical micelles. To circumvent this limitation, we benefited from the uniaxial growth of spherical micelles into long cylindrical micelles usually called wormlike or giant micelles, upon the addition of cosolutes. This paper describes the unprecedented formation of chiral giant micelles in aqueous solutions of cetyltrimethylammonium bromide (CTAB) upon increasing addition of enantiopure sodium salt of 1,1'-bi-2-naphthol (Nabinaphtholate) as a cosolute. Depending on the concentrations of CTAB and Na-binaphtholate, chiral gel-like systems are obtained. The transition from spherical to giant micellar structures was probed using theology, cryo-transmission electron microscopy, polarimetry, and electronic circular dichroism (CD). CD can be effectively used to monitor the incorporation of Nabinaphtholate into the micelle palisade as well as to determine its transition to giant micellar structures. Our approach expands the scope for chirality induction in micellar aggregates bringing the possibility to generate "smart" chiral systems and an alternative asymmetric chiral environment to perform enantioselective transformations.Over the past few years, chiral supramolecular assemblies have been successfully used for recognition, sensing and enantioselective transformations. Several approaches are available to control chirality of discrete assemblies (e.g., cages and capsules), b323384618466Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP, Sao Paulo, Brazil)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq, Brazil)ISF [741/11]Russell Berrie Nanotechnology Institute (RBNI)CNPq [301016/2015-1]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq
The Chameleon-Like Nature of Zwitterionic Micelles: Effect of Cation Binding
Addition of salts, especially perchlorates, to zwitterionic micelles of SB3-14, C(14)H(29)NMe(2)(+)(CH(2))(3)SO(3)(-), induces anionic character and uptake of H(3)O(+) by SB3-14 micelles. Thus, the addition of alkali metal perchlorates accelerates the acid hydrolysis of 2-(p-heptoxypheny1)-1,3-dioxolane, HPD, in the presence of SB3-14 micelles, which depends on the local proton concentration at the micelle surface. The addition of metal chlorides to solutions of such perchlorate-modified SB3-14 micelles decreases both the negative zeta potential of the micelles and the observed rate constant for acid hydrolysis of HPD. The effect of the monovalent cations Li(+), Na(+), and K(+) is smaller than that of the divalent cations Be(2+), Mg(2+), and Ca(2+), and much smaller than that of the trivalent cations Al(3+), La(3+), and Er(3+). The major factor responsible for this cation valence dependence of these effects is shown to be electrostatic in nature, reflecting the strong dependence of the micellar surface potential on the cation valence. The fact that the salt effects are not identical after correction for the electrostatic effects indicates that additional secondary nonelectrostatic effects may contribute as well.Conselho Nacional do Desenvolvimento Cientifico e Tecnologico (CNPq, Brazil)Conselho Nacional do Desenvolvimento Cientifico e Tecnologico (CNPq, Brazil)Fundacao de Amparo a Pesquisa e Inovacao do Estado de Santa Catarina (FAPESC)Fundacao de Amparo a Pesquisa e Inovacao do Estado de Santa Catarina (FAPESC)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES, Brazil)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES), Brazi
Ammonia oxide makes up some 20% of an aqueous solution of hydroxylamine
Three independent indirect estimates based on structure-reactivity correlations indicate that ca. 20% of hydroxylamine exists in aqueous solution as ammonia oxide, NH3+-O-