a-Glucosidase Inhibitors from a Xylaria feejeensis Associated with Hintonia latiflora

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Mario Figueroa Saldivar, Adjunct Faculty (Creator)
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/

Abstract: Two new compounds, pestalotin 4'-O-methyl-ß-mannopyranoside (1) and 3S,4R-(+)-4-hydroxymellein (2), were isolated from an organic extract of a Xylaria feejeensis, which was isolated as an endophytic fungus from Hintonia latiflora. In addition, the known compounds 3S,4S-(+)-4-hydroxymellein (3), 3S-(+)-8-methoxymellein (4), and the quinone derivatives 2-hydroxy-5-methoxy-3-methylcyclohexa-2,5-diene-1,4-dione (5), 4S,5S,6S-4-hydroxy-3-methoxy-5-methyl-5,6-epoxycyclohex-2-en-1-one (6), and 4R,5R-dihydroxy-3-methoxy-5-methylcyclohexen-2-en-1-one (7) were obtained. The structures of 1 and 2 were elucidated using a set of spectroscopic and spectrometric techniques. The absolute configuration of the stereogenic centers of 1 and 2 was determined using ECD spectroscopy combined with time-dependent density functional theory calculations. In the case of 1, comparison of the experimental and theoretical 3J6–7 coupling constants provided further evidence for the stereochemical assignments. Compounds 2 and 3 inhibited Saccharomyces cerevisiae a-glucosidase (aGHY), with IC50 values of 441 ± 23 and 549 ± 2.5 µM, respectively. Their activity was comparable to that of acarbose (IC50 = 545 ± 19 µM), used as positive control. Molecular docking predicted that both compounds bind to aGHY in a site different from the catalytic domain, which could imply an allosteric type of inhibition.

Additional Information

Journal of Natural Products, 78 (4), pp. 730-735
Language: English
Date: 2015
Xylaria feejeensis, Hintonia latiflora, type II diabetes mellitus treatments

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