Self-condensation of n-(N-propyl)butanimine: NMR and mass spectral analyses and investigation by theoretical calculation

The stability of N-propylbutanimine (1) was investigated under different experimental conditions. The acid-catalyzed self-condensation that produced the E-enimine (4) and Z-inimine (5) was studied by experimental analyses and theoretical calculations. Since the calculations for the energy of 5 indicated that it had a lower energy than 4, yet 4 was the principal product, the self-condensation of 1 must be kinetically controlled

Síntese de derivados de n-acetilglicosamina e investigação de sua atividade antimicrobiana

Exportado OPUSMade available in DSpace on 2019-08-13T02:31:05Z (GMT). No. of bitstreams: 1 tese_pdf_rozangela.pdf: 9026417 bytes, checksum: a12235ecffec1848dfc3217a68787cd4 (MD5) Previous issue date: 6Na presente tese relata-se a síntese de glicosídeos de arila derivados da N-acetilglicosamina, unidade monomérica da quitina, componente polimérico importante da parede dos fungos, como potenciais agentes antifúngicos e antibacterianos. Inicialmente foi efetuada modificação na posição C-6 dos N-acetilglicosaminídeos de 4-metilfenila e 4-metoxicarbonilfenila, por grupos azido, amino e acetamido. Em seguida, relata-se a síntese de derivados 3,6- e 4,6-diazido pela reação de derivados 4,6-O-dimesilados de configuração e do N-acetilglicosaminídeo de 4-metilfenila, com azida de sódio. Quando a reação foi efetuada com o anômero di-O-mesilado o único produto isolado foi o derivado 3,6-diazido de configuração D-gulo, resultante da abertura de epóxido formado intermediariamente. A reação do anômero 4,6-di-O-mesilado ocorreu via formação e abertura de epóxido ou via reação de SN2 clássica, com a formação de produtos 4,6-glico e 3,6-gulo (via abertura de epóxido) e 4,6-galacto (reação SN2). Nenhuma das substâncias avaliadas até o momento apresentou atividade antifúngica para fungo filamentoso (Aspergillus niger) e leveduras (Saccharomyces cerevisiae, Candida albicans e Candida tropicalis) pelo método da difusão em ágar na concentração de 1 mg/mL. Em avaliação da atividade antibacteriana (Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Escherichia coli e Pseudomonas aeruginosa), pelo mesmo método, 2-acetamido-4,6-O-benzilideno-2-desoxi- -D-glicopiranosídeo de 4-metilfenila apresentou halo de inibição difuso de 24,31 1,63 mm contra a cepa de Bacillus subtilis, na concentração de 1 mg/ml. O cloranfenicol, utilizado como padrão, na concentração de 1 mg/mL, apresentou halo de inibição de 22,07 1,82 mm.In this work is described the synthesis of aryl glycosides derived from Nacetylglucosamine, monomeric unit of chitin polymer, essential component of the fungal cell wall, as potential antifungal and antimicrobial agents. Initially, modification at C-6 position of 4-methylphenyl and 4-methoxycarbonylphenyl N-acetylglucosaminides by azido, amino and acetamido groups was performed. Next is described the synthesis of 3,6- and 4,6-diazido derivatives by reacting the b and a anomers of 4,6-O-dimesylate of the 4- methylphenyl N-acetylglucosaminide with sodium azide. When the reaction was performed with the b anomer of the di-O-mesylated derivative, the sole compound isolated was the 3,6-diazido derivative with D-gulo configuration, arising from the opening of the epoxide formed during the reaction. The reaction of the a anomer of the di-O-mesylated derivative resulted in the isolation of three compounds: the 4,6-diazido derivative of the D-galacto series obtained by direct SN2 displacement of the mesylate groups, and the 3,6-diazido derivative of the D-gulo series and 4,6-diazido derivative of the D-gluco configuration, arising from the opening of the epoxide formed during the reaction. None of the compounds showed antifungal activity against filamentous fungi (Aspergillus niger) and yeast (Saccharomyces cerevisae, Cândida albicans and Cândida tropicallis), when evaluated using the agar diffusion method, in the concentration of 1 mg/mL. In the evaluation of the antibacterial activity against Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Escherichia coli e Pseudomonas aeruginosa, by the same procedure, 4-methylphenyl 2-acetamido-4,6-O-benzylidene-2-deoxy-a-D-glucopyranoside showed a diffuse inhibition halo of 24.31 ± 1.63 mm against Bacillus subtilis, in the concentration of 1 mg/mL. Chloranfenicol, used as standard in the concentration of 1 mg/mL, showed an inhibition halo of 22.07 ± 1.82 mm

Self-condensation of n-(N-propyl)butanimine: NMR and mass spectral analyses and investigation by theoretical calculation

Submitted by Nuzia Santos ([email protected]) on 2014-05-29T19:41:10Z No. of bitstreams: 1 Self-condensation of n-(N-propyl)butanimine.pdf: 1379707 bytes, checksum: 49ab766b53e5fd7e39797e711858ce07 (MD5)Made available in DSpace on 2014-05-29T19:41:10Z (GMT). No. of bitstreams: 1 Self-condensation of n-(N-propyl)butanimine.pdf: 1379707 bytes, checksum: 49ab766b53e5fd7e39797e711858ce07 (MD5) Previous issue date: 2012Universidade Federal de Minas Gerais. Instituto de Ciências Exatas. Departamento de Química. Belo Horizonte, MG, BrasilUniversidade Federal de Minas Gerais. Instituto de Ciências Exatas. Departamento de Química. Belo Horizonte, MG, BrasilUniversidade Federal de Minas Gerais. Instituto de Ciências Exatas. Departamento de Química. Belo Horizonte, MG, BrasilUniversidade Federal de Minas Gerais. Instituto de Ciências Exatas. Departamento de Química. Belo Horizonte, MG, BrasilUniversidade Federal de Minas Gerais. Faculdade de Farmácia. Departamento de Alimentos. Belo Horizonte, MG, BrasilFundação Oswaldo CruzCentro de Pesquisas René Rachou. Laboratório de Química de Produtos Naturais. Belo Horizonte, MG, BrasilThe stability of N-propylbutanimine (1) was investigated under different experimental conditions. The acid-catalyzed self-condensation that produced the E-enimine (4) and Z-inimine (5) was studied by experimental analyses and theoretical calculations. Since the calculations for the energy of 5 indicated that it had a lower energy than 4, yet 4 was the principal product, the self-condensation of 1 must be kinetically controlled

Síntese de beta-N-acetilglicosaminídeos de arila modificados em C-6 como potenciais agentes antimicrobianos

We report herein the synthesis of aryl beta-N-acetylglucosaminides containing azido, amino and acetamido groups at C-6 as potential antimicrobial agents. It was expected that these compounds could interfere with the biosynthesis and/or biotransformation of N-acetylglucosamine in fungi and bacteria. None of the compounds showed antimicrobial activity against bacteria (Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa), filamentous fungus (Aspergillus niger) and yeasts (Saccharomyces cerevisae, Candida albicans and Candida tropicallis), at the concentration of 1 mg/mL in agar diffusion assay

Chemical constituents from the stem of Brosimum potabile (Moraceae) Constituintes químicos do cerne de Brosimum potabile (Moraceae)

Three coumarins, 5-methoxypsoralene, xanthyletin, and (-)-marmesin, have been isolated from the ethanolic extract of the stem of the Amazonian plant Brosimum potabile. The structures were determined on the basis of NMR analyses and by comparison with spectroscopic data in the literature. The analysis of the hexane fractions by GC-MS in EIMS mode suggested the presence of (1-methylpentyl)-benzene; &#945;,&#945;-dimethyl-4-(1-methylethyl)-benzenemethanol; 1-methyl-3,5-bis(1-methylethyl)-benzene; urs-12-ene; chola-5,22-dien-3&#946;-ol; cholesta-4,6-dien-3&#946;-ol; sitosteryl 9(Z)-octadecenoate; cholesta-5,22-dien-3&#946;-ol; cholesta-4,6,22-trien-3-one; and cholesta-4,22-dien-3-one. NMR data of other hexane fractions indicated the presence of 3&#946;-acetoxy-lup-12,20(29)-diene; 3&#946;-acetoxy-olean-12-ene; 3&#946;-acetoxy-urs-12-ene; and adian-5-ene. All these compounds are first described in B. potabile.<br>Três cumarinas, 5-metoxipsoraleno, xantiletina e (-)-marmesina, foram isoladas no extrato etanólico do cerne da planta amazônica Brosimum potabile. Suas estruturas foram determinadas a partir das análises por RMN e por comparação com dados espectroscópicos da literatura. As análises das frações hexânicas por CG/EM sugeriram a presença de (1-metilpentil)-benzeno; &#945;,&#945;-dimetil-4-(1-metiletil)-benzenometanol; 1-metil-3,5-bis(1-metiletil)-benzeno; urs-12-eno; cola-5,22-dien-3&#946;-ol; colesta-4,6-dien-3&#946;-ol; (9Z)-octadecenoato de sitosterila; colesta-5,22-dien-3&#946;-ol; colesta-4,6,22-trien-3-ona e colesta-4,22-dien-3-ona. Dados de RMN de outras frações hexânicas indicaram a presença de 3&#946;-acetóxi-lup-12,20(29)-dieno; 3&#946;-acetóxi-olean-12-eno; 3&#946;-acetóxi-urs-12-eno e adian-5-eno. Todos esses compostos foram identificados pela primeira vez em B. potabile