Chemical Constituents of Muehlenbeckia tamnifolia (Kunth) Meisn (Polygonaceae) and Its In Vitro α-Amilase and α-Glucosidase Inhibitory Activities.
The phytochemical investigation ofMuehlenbeckia tamnifolia, collected in Loja-Ecuador, led to the isolation of nine known compounds identified as: lupeol acetate (1);cis-p-coumaric acid (2); lupeol (3); β-sitosterol (4)trans-p-coumaric acid (5); linoleic acid (6) (+)-catechin (7); afzelin (8) and quercitrin (9). The structures of the isolated compounds were determined based on analysis of NMR and MS data, as well as comparison with the literature. The hypoglycemic activity of crude extracts and isolated compounds was assessed by the ability to inhibit α-amylase and α-glucosidase enzymes. The hexane extract showed weak inhibitory activity on α-amylase, with an IC50value of 625 µg·mL-1, while the other extracts and isolated compounds were inactive at the maximum dose tested. The results on α-glucosidase showed more favorable effects; the hexanic and methanolic extracts exhibited a strong inhibitory activity with IC50values of 48.22 µg·mL-1and 19.22 µg·mL-1, respectively. Four of the nine isolated compounds exhibited strong inhibitory activity with IC50values below 8 µM, much higher than acarbose (377 uM). Linoleic acid was the most potent compound (IC50= 0.42 µM) followed by afzelin, (+)-catechin and quercitrin.
Departamento de Química, Universidad Técnica Particular de Loja, Loja 1101608, Ecuador. mbeltorres15@hotmail.com.
María
M
Torres-Naranjo
Facultad de Farmacia, Universidad Central de Venezuela, Caracas 1040, Venezuela. alirica1@yahoo.es.|Prometeo Project Researcher, SENESCYT, Quito 170516, Ecuador. alirica1@yahoo.es.
Alirica
A
Suárez
Departamento de Química, Universidad Técnica Particular de Loja, Loja 1101608, Ecuador. gianluca.gilardoni@gmail.com.
Gianluca
G
Gilardoni
Departamento de Química, Universidad Técnica Particular de Loja, Loja 1101608, Ecuador. lecartuche@utpl.edu.ec.
Luis
L
Cartuche
Departamento de Química, Universidad Técnica Particular de Loja, Loja 1101608, Ecuador. pkflores@utpl.edu.ec.
Paola
P
Flores
Departamento de Química, Universidad Técnica Particular de Loja, Loja 1101608, Ecuador. svmorocho@utpl.edu.ec.
Vladimir
V
Morocho
D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000494:pharmacology*; D065089:Glycoside Hydrolase Inhibitors / Q000737:chemistry / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D064209:Phytochemicals / Q000737:chemistry / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology*; D019664:Polygonaceae / Q000737:chemistry*; D000516:alpha-Amylases / Q000037:antagonists & inhibitors*; D000520:alpha-Glucosidases
D004791:Enzyme Inhibitors; D065089:Glycoside Hydrolase Inhibitors; D064209:Phytochemicals; D010936:Plant Extracts; D000516:alpha-Amylases; D000520:alpha-Glucosidases
Muehlenbeckia tamnifolia; linoleic acid; α-amilase inhibition; α-glucosidase inhibition