RESUMO
The phytochemical study of the whole plant of Derris scandens (Leguminosae) has resulted in the isolation of a new isoflavone derivative, scandinone A (11), together with 11 known compounds (1-10, 12). Structural elucidations of these compounds were performed using spectroscopic methods especially 1D, 2D NMR, and mass spectral analyses. The alpha-glucosidase-inhibitory activity of the isolates was also evaluated.
Assuntos
Derris/química , Inibidores de Glicosídeo Hidrolases , Isoflavonas/isolamento & purificação , Plantas Medicinais/química , Índia , Isoflavonas/química , Isoflavonas/farmacologia , Estrutura Molecular , PrenilaçãoRESUMO
Phytochemical investigation of antihyperglycemic extract of rhizomes of Hedychium spicatum led to the isolation of two new labdane type diterpenes 2, 3 along with seven known compounds (1, 4-9). Their structures were established on the basis of NMR (1D and 2D) and mass spectroscopic analysis. The new compound 2 displayed strong intestinal alpha-glucosidase inhibitory activity. Other compounds also displayed varying degree of intestinal alpha-glucosidase inhibitory potential.
Assuntos
Química Farmacêutica/métodos , Inibidores Enzimáticos/farmacologia , Inibidores de Glicosídeo Hidrolases , Rizoma/química , Zingiberaceae/metabolismo , Animais , Desenho de Fármacos , Hipoglicemiantes/farmacologia , Espectroscopia de Ressonância Magnética , Masculino , Espectrometria de Massas/métodos , Fitoterapia/métodos , Extratos Vegetais/metabolismo , Ratos , Ratos WistarRESUMO
A bioassay-guided fractionation and chemical examination of antihyperglycemic root extract of Derris indica resulted in isolation and characterization of two new furanoflavanoids (1, 2) along with thirteen known compounds (3-15). Their structures were determined on the basis of extensive spectroscopic (IR, MS, 1D and 2D NMR) data analysis and by comparison with the literature data. All the compounds were tested in vitro for intestinal alpha-glucosidase inhibitory and DPPH radical activity. New compounds (1, 2) displayed moderate intestinal alpha-glucosidase inhibitory as well as free radical scavenging activity. Other compounds also displayed varying degrees of moderate intestinal alpha-glucosidase inhibitory activity. Pongamol (6) displayed potent intestinal alpha-glucosidase inhibition.
Assuntos
Derris/química , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Inibidores de Glicosídeo Hidrolases , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Raízes de Plantas/química , Animais , Compostos de Bifenilo/metabolismo , Flavonoides/química , Flavonoides/farmacologia , Furanos/química , Furanos/farmacologia , Intestinos/enzimologia , Estrutura Molecular , Picratos/metabolismo , Ratos , Ratos Wistar , alfa-Glucosidases/metabolismoRESUMO
A series of beta-acetamido carbonyl compounds (S(1)-S(7)) were prepared using Dakin-West reaction from different substituted aldehyde and acetophenone in the presence of lanthanum triflate as a solid catalyst. All the compounds were tested for their alpha-glucosidase inhibitory potential against rat intestinal alpha-glucosidase. The most potent rat intestinal alpha-glucosidase inhibitors S(5) and S(7) were tested for their antihyperglycemic activity following carbohydrate tolerance test. Both the compounds displayed antihyperglycemic activity equivalent to the standard drug acarbose.
Assuntos
Acetamidas/química , Carbono/química , Inibidores de Glicosídeo Hidrolases , Hiperglicemia/metabolismo , Hipoglicemiantes/síntese química , Intestinos/enzimologia , alfa-Glucosidases/química , Acarbose/química , Animais , Carboidratos/química , Diabetes Mellitus Experimental/tratamento farmacológico , Desenho de Fármacos , Hiperglicemia/tratamento farmacológico , Hipoglicemiantes/farmacologia , Modelos Químicos , Período Pós-Prandial , RatosRESUMO
A series of 8-aminomethylated derivatives (1a-1j) were prepared by Mannich reaction of oroxylin A (1) with appropriate primary or secondary amines and para-formaldehyde. All the compounds were tested for their alpha-glucosidase inhibition activity against both yeast and rat intestinal alpha-glucosidase. Some of the compounds demonstrated significantly better alpha-glucosidase inhibitory activity than the parent compound (oroxylin A).
Assuntos
Flavonoides/química , Flavonoides/farmacologia , Inibidores de Glicosídeo Hidrolases , Animais , Intestinos/enzimologia , Ratos , Saccharomyces cerevisiae/enzimologia , Relação Estrutura-AtividadeRESUMO
The methanolic extract of rhizome of Himalayan rhubarb Rheum emodi displayed mild yeast as well as mammalian intestinal alpha-glucosidase inhibitory activity. However, further fractionation of active extract led to the isolation of several potent molecules in excellent yields, displaying varying degrees of inhibition on two test models of alpha-glucosidase. Rhapontigenin, desoxyrhapontigenin, chrysophanol-8-O-beta-d-glucopyranoside, torachrysone-8-O-beta-d-glucopyranoside displayed potent yeast alpha-glucosidase inhibition. However chrysophanol-8-O-beta-d-glucopyranoside, desoxyrhaponticin and torachrysone-8-O-beta-d-glucopyranoside displayed potent to moderate mammalian alpha-glucosidase inhibitory activity. Other compounds displayed mild activity on both the tests. Except desoxyrhapontigenin and rhapontigenin that increased Vmax, other compounds including crude extract decreased the Vmax significantly (p<0.02) in yeast alpha-glucosidase test. Further kinetic analysis on mammalian alpha-glucosidase inhibition showed that chrysophanol-8-O-beta-d-glucopyranoside, desoxyrhaponticin and torachrysone-8-O-beta-d-glucopyranoside may be classified as mixed-noncompetitive inhibitors. However, desoxyrhapontigenin and rhapontigenin may be classified as modulators of enzyme activity. Presence and position of glycoside moiety in compounds appear important for better inhibition of mammalian alpha-glucosidase. This is the first report assigning particularly, mammalian intestinal alpha-glucosidase inhibitory activity to these compounds. Chrysophanol-8-O-beta-d-glucopyranoside, desoxyrhaponticin, desoxyrhapontigenin and rhapontigenin have been isolated in substantial yields from R. emodi for the first time. Therefore, these compounds may have value in the treatment and prevention of hyperglycemia associated diabetes mellitus.
Assuntos
Inibidores Enzimáticos/farmacologia , Inibidores de Glicosídeo Hidrolases , Rheum/química , Animais , Ligação Competitiva , Diabetes Mellitus/tratamento farmacológico , Diabetes Mellitus/prevenção & controle , Inibidores Enzimáticos/isolamento & purificação , Inibidores Enzimáticos/uso terapêutico , Hiperglicemia/tratamento farmacológico , Hiperglicemia/prevenção & controle , Mucosa Intestinal/metabolismo , Cinética , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ratos , Estilbenos/química , Estilbenos/farmacologia , Leveduras , alfa-Glucosidases/isolamento & purificação , alfa-Glucosidases/metabolismoRESUMO
A new isomer of mesquitol (2,3-trans-3',4',7,8-tetrahydroxyflavan-3-ol) was isolated from Dichrostachys cinerea in excellent yields. It has shown free-radical scavenging property and alpha-glucosidase inhibitory activities but, it could not display xanthine oxidase inhibitory property. However, it was observed that acylation of 3-OH group significantly enhanced the alpha-glucosidase inhibition and displayed xanthine oxidase inhibitory potential. The structure activity relationship revealed that the degree of lipophilicity played a major role in improving enzyme inhibitory activities. A positive correlation was observed between enzyme inhibitory potential and acyl chain length (upto C-16) of aliphatic esters.