Monoamine oxidase inhibitory naphthoquinones from the roots of Lithospermum erythrorhizon.
Activity-guided fractionation of a hexane-soluble extract of the roots of Lithospermum erythrorhizon, using a mouse brain monoamine oxidase (MAO) inhibition assay, led to the isolation of two known naphthoquinones, acetylshikonin and shikonin, and a furylhydroquinone, shikonofuran E. These compounds were shown to inhibit MAO with IC50 values of 10.0, 13.3, and 59.1 microM, respectively. Although no specificity for MAO-A and MAO-B was shown by acetylshikonin and shikonin, a Lineweaver-Burk plot analysis indicated that the inhibition was competitive for both MAO-A and MAO-B activity.
Choi
Woo Hoi
WH
College of Pharmacy, Chungbuk National University, Cheongju 361-763, Korea and 2Research Center for Bioresource and Health, Chungbuk National University, Cheongju 361-763, Korea.
Hong
Seong Su
SS
Lee
Seon A
SA
Han
Xiang Hua
XH
Lee
Kyong Soon
KS
Lee
Myung Koo
MK
Hwang
Bang Yeon
BY
Ro
Jai Seup
JS
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology; D066298:In Vitro Techniques; D029684:Lithospermum / Q000737:chemistry*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D015394:Molecular Structure; D008995:Monoamine Oxidase / Q000378:metabolism; D008996:Monoamine Oxidase Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology; D009285:Naphthoquinones / Q000302:isolation & purification* / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry; D013379:Substrate Specificity
D008996:Monoamine Oxidase Inhibitors; D009285:Naphthoquinones; D008995:Monoamine Oxidase