Henriete S. Vieira
Universidade Federal de Minas Gerais
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Featured researches published by Henriete S. Vieira.
Journal of the Brazilian Chemical Society | 2002
Henriete S. Vieira; Jacqueline A. Takahashi; Alaíde Braga de Oliveira; Egler Chiari; Maria Amélia D. Boaventura
Kaurenoic acid, a kauranic diterpenoid, presents in vitro activity against trypomastigote forms of Trypanosoma cruzi, showing, however, lytic activity on blood erythrocytes, as a side effect. The syntheses of twelve new derivatives of kaurenoic acid, four amides, four amines (and three hydroclorides) and four oximes, was carried out aiming at the improvement of the therapeutic activity and without the side effect. Among the derivatives prepared, one compound showed enhanced trypanocidal activity in vitro towards Trypanosoma cruzi trypomastigote erythrocytic forms, when compared to kaurenoic acid, but continued to show discrete lytic activity on erythrocytes; another compound showed a level of activity similar to that of kaurenoic acid, but without lysis.
Fitoterapia | 2001
Henriete S. Vieira; Jacqueline A. Takahashi; Maria Amélia D. Boaventura
Tetrachyrin (1), 3alpha-tigloyloxykaur-16-en-19-oic acid (2) and 3alpha-cinnamoyloxykaur-16-en-19-oic acid (3) have been isolated from the ethanol extract of Wedelia paludosa aerial parts.
Química Nova | 2001
Jacqueline A. Takahashi; Henriete S. Vieira; Maria Amélia D. Boaventura; James R. Hanson; Peter B. Hitchcock; Alaíde Braga de Oliveira
A monoterpene, 3b,6b-dihydroxy-p-menth-1-ene has been isolated from the seeds of Xylopia sericea along with four kaurane, one beyerene, one atisene and four trachylobane diterpenoids, including the trachyloban-18- and 19-methyl esters. The X-ray crystal structure of methyl ent-trachyloban-18-oate was determined in order to make an unambiguous distinction between the 18- and 19-esters. The 13C NMR data for ent-15a-hydroxy-trachyloban-19-oic acid has been revised.
Zeitschrift für Naturforschung C | 2005
Henriete S. Vieira; Jacqueline A. Takahashi; Lúcia Pinheiro Santos Pimenta; Maria Amélia D. Boaventura
Kaurenoic and grandiflorenic acid, isolated from Wedelia paludosa (Asteraceae), some derivatives from these acids (alcohols, esters, amides, lactones, oximes) and other naturally occurring kaurane diterpenes were tested for their action on the growth of radical and shoot of Lactuca sativa. Gibberellic acid, GA3, a commercially available phytohormone, belonging to the same class of diterpenes, was also tested. Some of the tested substances showed a remarkable activity either in the inhibition or in stimulation of L. sativa growth. The activity, in some cases, was even higher than that of GA3.
Journal of Agricultural and Food Chemistry | 2008
Maria Amélia D. Boaventura; Rondinelle Gomes Pereira; Luiza Baptista de Oliveira Freitas; Leandro Alves Dos Reis; Henriete S. Vieira
Novel kaurane ditepene monoamides were synthesized in good yields directly from kaurenoic ( 1) and grandiflorenic ( 2) acids and unprotected symmetrical diamines, using a modified protocol for monoacylation. Amides from 1 and 2 and monoamines were also obtained and tested against seed germination and growth of radicle and shoot of Lactuca sativa (lettuce), at 10 (-3), 10 (-5), and 10 (-7) M. Amides from symmetrical diamines showed significant inhibitory activity at higher concentrations.
Applied Microbiology and Biotechnology | 2000
Henriete S. Vieira; Jacqueline A. Takahashi; Maria Amélia D. Boaventura
Abstract Methyl ent-17-hydroxy-16β-kauran-19-oate was fed to a 2-day-old culture of the fungus Rhizopus stolonifer, fermenting at room temperature (25 °C) in an orbital shaker (2 l). After 11 days, both broth and mycelia were extracted with ethyl acetate. Two novel compounds were isolated from this experiment: methyl ent-9α,17-dihydroxy-16β-kauran-19-oate and methyl ent-7α,17-dihydroxy-16β-kauran-19-oate. Their structures were fully confirmed by spectroscopic methods.
Journal of the Brazilian Chemical Society | 2018
Rosangela da Costa e Silva; Luciano Roni Silva Lara; Jorge López; Ângela Leão Andrade; Junnia Oliveira; Jacqueline A. Takahashi; Henriete S. Vieira; Tulio Matencio; Humberto O. Stumpf; Rosana Zacarias Domingues
A novel, fast, low-cost and scalable methodology to prepare stable magnetoliposomes (MGLs), without the use of organic solvents, is described. The concept of the work is based on the dual use of soy lecithin associated to a new liposome preparation methodology. Soy lecithin was used to coat the nanoparticles of magnetite (Fe3O4@lecithin) and for encapsulation of Fe3O4@lecithin (Lip-Fe3O4@lecithin). Liposomes with size less than 160 nm, polydispersity index of 0.25 and zeta potential of –41 mV, were prepared with the use of autoclave and sonication. The liposomal formulations containing magnetite and stigmasterol (Lip-Fe3O4@lecithin, Lip-Stigma and Lip-Stigma-Fe3O4@lecithin) were shown to be promising for the application as antibacterial. The liposomal formulation and magnetite were characterized by the following techniques: conventional and high-resolution transmission electron microscopy (TEM/HRTEM), energy-filtered transmission electron microscopy (EFTEM), proton nuclear magnetic resonance (H NMR), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRPD), dynamic light scattering (DLS) and zeta potential. The Lip-Fe3O4@lecithin had a minimum inhibitory concentration (MIC) of 8.4 μg mL in the presence of 200 Oe magnetic field against S. aureus.
Anais Da Academia Brasileira De Ciencias | 2018
Maria Amélia D. Boaventura; Laura F.W. Xavier; Henriete S. Vieira; Jacqueline A. Takahashi; Wilton J.D. Nascimento Junior; Tamires P. Araujo; Amanda Cristina Soares Coelho
Thirteen natural products derivatives of hydroxyl amide class, three described for the first time, were synthesized by reaction of three indole acids and 3,4,5-trimethoxybenzoic acid with six different amino alcohols in the presence of triphenylphosphine and N-bromosuccinimide. The derivatives were tested against the Gram (+) bacteria Staphylococcus aureus and Bacillus cereus, Gram (-) Pseudomonas aeruginosa and Escherichia coli, besides the yeast Candida albicans. One of the compounds (7) was selectively active against C. albicans (91.3 ± 0.49% inhibition) showing a great potential as a new drug lead, since it was more active than the positive control, miconazole (88.7 ± 2.41% inhibition). Regarding bacterial inhibition, compounds demonstrated mild activity, but inhibition of compounds 9, 10 and 13 towards E. coli is of interest since it is difficult to find drugs selectively active against Gram (-) bacteria. Most of the compounds were very active in the acetylcholinesterase inhibition assay. Compound 7 was again the most active (93.2 ± 4.47%), being more potent than the control galantamine (90.3 ± 0.45%). The most active gallic acid derivatives, compounds 3, 7 and 8 have in common, besides gallic acid skeleton, a (CH2)2OH group, which may be one of the structural requirements for AChE inhibition.
Archive | 2002
Henriete S. Vieira; Jacqueline A. Takahashi; Alaíde Braga de Oliveira; Egler Chiari; Maria Amélia; D. Boaventura; Departamento de Química
Journal of Agricultural and Food Chemistry | 2002
Henriete S. Vieira; Jacqueline A. Takahashi; Maria Amélia D. Boaventura