@Article{phyton.2020.08328,
AUTHOR = {Swastika Paul, Xuemei Zhang, Yongping Yang, Changan Geng},
TITLE = {Chemical Constituents from Turnip and Their Effects on <i>α</i>-Glucosidase},
JOURNAL = {Phyton-International Journal of Experimental Botany},
VOLUME = {89},
YEAR = {2020},
NUMBER = {1},
PAGES = {131--136},
URL = {http://www.techscience.com/phyton/v89n1/38406},
ISSN = {1851-5657},
ABSTRACT = {<i>Brassica rapa</i> var. <i>rapa</i> (turnip) is an important crop in Qinghai-Tibet 
Plateau (QTP) with anti-hypoxic effect. Turnip is rich in glucosinolates, 
isothiocyanates and phenolic compounds with diverse biological activities, 
involving anti-oxidant, anti-tumor, anti-diabetic, anti-inflammatory, anti-microbial, 
hypolipidemic, cardioprotective, hepatoprotective, nephroprotective and analgesic 
properties. In this study, the ethyl acetate (EtOAc) and butanol parts of <i>Brassica 
rapa</i> were first revealed with inhibitory effects on <i>α</i>-glucosidase, whereas the water 
part was inactive. Subsequent bioassay-guided isolation on the EtOAc and butanol 
parts yielded 12 compounds, involving three indole derivatives, indole-3-
acetonitrile (1) 4-methoxyindole-3-acetonitrile (2) and indole-3-aldehyde (3) two 
flavonoids, liquiritin (4) and licochalcone A (5) two phenylpropanoids, sinapic acid 
(6) and caffeic acid (7) two phenylethanol glycosides, 2-phenylethyl <i>β</i>-
glucopyranoside (8) and salidroside (9) and three other compounds, syringic acid 
(10) adenosine (11) and (3<i>β</i>, 20<i>E</i>)-ergosta-5, 20 (22)-dien-3-ol (12) Licochalcone 
A (5) and caffeic acid (7) showed <i>α</i>-glucosidase inhibitory activity with IC<sub>50</sub> values 
of 62.4 ± 8.0 μM and 162.6 ± 3.2 μM, comparable to the positive control, acarbose 
(IC<sub>50</sub> = 142 ± 0.02 μM). Docking study suggested that licochalcone A (5) could 
well align in the active site of α-glucosidase (docking score = -52.88) by forming 
hydrogen bonds (Gln1372, Asp1420, Gln1372, Arg1510), hydrophobic effects 
(Tyr1251, Tyr1251, Trp1355, Phe1560, Ile1587, Trp1355, Phe1559, Phe1559) and 
π-π stacking interaction (Trp1355). This study provides valuable information for 
turnip as a new resource in searching anti-diabetic candidates.},
DOI = {10.32604/phyton.2020.08328}
}