TY - JOUR
T1 - Antioxidant and Antidiabetic Activities of Flavonoid Derivatives from the Outer Skins of Allium cepa L.
AU - Vu, Ngoc Khanh
AU - Kim, Chung Sub
AU - Ha, Manh Tuan
AU - Ngo, Quynh Mai Thi
AU - Park, Se Eun
AU - Kwon, Haeun
AU - Lee, Dongho
AU - Choi, Jae Sue
AU - Kim, Jeong Ah
AU - Min, Byung Sun
N1 - Funding Information:
This research was supported by the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (2015M3A9A5031271 and 2020R1F1A1072001), Korea. We are thankful to the Korea Basic Science Institute (KBSI) for mass spectrometric measurements.
PY - 2020/8/19
Y1 - 2020/8/19
N2 - The onion, known as the bulb onion or common onion, is not only a key ingredient in many tasty and healthy vegetarian meals but also many traditional medicines. Nine new flavonoids [cepaflavas A, B (5, 6), cepadials A-D (7-9 and 14), and cepabiflas A-C (10-12)] and six known compounds (1-4, 13, 15) were obtained from the outer skins of Allium cepa L. Among them, compounds 5, 6, and 9 might be artificial products formed during extraction and isolation. New compounds were structurally elucidated using various spectroscopy/spectrometry techniques, including NMR and HRMS, and computational methods. Their absolute configurations were determined using time-dependent density functional theory calculations, combined with ECD spectroscopy, optical rotation calculation, and statistical procedures (CP3 and DP4 analysis). The free radical scavenging assays revealed that the new compounds 10-12 possessed considerable antioxidant activities with IC50 values of 4.25-8.88 and 7.12-8.14 μM against DPPH and ABTSâ +, respectively. Compounds 13-15 showed substantial inhibitory activities against both α-glucosidase and protein tyrosine phosphatase 1B (PTP1B), with IC50 values of 0.89-6.80 and 1.13-6.82 μM, respectively. On the basis of molecular docking studies, 13 and 15 were predicted to have high binding capacity and strong affinity toward the active site of PTP1B.
AB - The onion, known as the bulb onion or common onion, is not only a key ingredient in many tasty and healthy vegetarian meals but also many traditional medicines. Nine new flavonoids [cepaflavas A, B (5, 6), cepadials A-D (7-9 and 14), and cepabiflas A-C (10-12)] and six known compounds (1-4, 13, 15) were obtained from the outer skins of Allium cepa L. Among them, compounds 5, 6, and 9 might be artificial products formed during extraction and isolation. New compounds were structurally elucidated using various spectroscopy/spectrometry techniques, including NMR and HRMS, and computational methods. Their absolute configurations were determined using time-dependent density functional theory calculations, combined with ECD spectroscopy, optical rotation calculation, and statistical procedures (CP3 and DP4 analysis). The free radical scavenging assays revealed that the new compounds 10-12 possessed considerable antioxidant activities with IC50 values of 4.25-8.88 and 7.12-8.14 μM against DPPH and ABTSâ +, respectively. Compounds 13-15 showed substantial inhibitory activities against both α-glucosidase and protein tyrosine phosphatase 1B (PTP1B), with IC50 values of 0.89-6.80 and 1.13-6.82 μM, respectively. On the basis of molecular docking studies, 13 and 15 were predicted to have high binding capacity and strong affinity toward the active site of PTP1B.
KW - Allium cepa skins
KW - PTP1B
KW - antioxidant
KW - kinetic
KW - molecular docking
KW - α-glucosidase
UR - http://www.scopus.com/inward/record.url?scp=85089712432&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85089712432&partnerID=8YFLogxK
U2 - 10.1021/acs.jafc.0c02122
DO - 10.1021/acs.jafc.0c02122
M3 - Article
C2 - 32603104
AN - SCOPUS:85089712432
VL - 68
SP - 8797
EP - 8811
JO - Journal of Agricultural and Food Chemistry
JF - Journal of Agricultural and Food Chemistry
SN - 0021-8561
IS - 33
ER -