Monoamine oxidase inhibitory coumarins from the aerial parts of Dictamnus albus.
The methanol extract from the aerial parts of Dictamnus albus was active in inhibiting monoamine oxidase (MAO) from the mouse brain. Activity-guided fractionation led to the isolation of four known coumarins, 7-(6'R-hydroxy-3', 7'-dimethyl-2'E, 7'-octadienyloxy) coumarin (1), auraptene (2), umbelliferone (3), and xanthotoxin (4), as active compounds along with an inactive alkaloid, skimmianine (5). Compounds 1 and 2 inhibited MAO activity in a concentration-dependent manner with IC50 values of 0.7 and 1.7 microM, respectively. Compounds 1 and 2 showed a slight and potently selective inhibitory effect against MAO-B (IC50 0.5 and 0.6 microM, respectively) compared to MAO-A (IC50 1.3 and 34.6 microM, respectively). According to kinetic analyses derived by Lineweaver-Burk reciprocal plots, compounds 1 and 2 exhibited a competitive inhibition to MAO-B.
Jeong
Seon Hwa
SH
College of Pharmacy, Chungbuk National University, Cheongju 361-763, Korea.
Han
Xiang Hua
XH
Hong
Seong Su
SS
Hwang
Ji Sang
JS
Hwang
Ji Hye
JH
Lee
Dongho
D
Lee
Myung Koo
MK
Ro
Jai Seup
JS
Hwang
Bang Yeon
BY
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology; D003010:Clorgyline / Q000494:pharmacology; D003374:Coumarins / Q000494:pharmacology*; D036905:Dictamnus / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology; D008995:Monoamine Oxidase / Q000378:metabolism; D008996:Monoamine Oxidase Inhibitors; D012642:Selegiline / Q000494:pharmacology; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet
D003374:Coumarins; D008996:Monoamine Oxidase Inhibitors; D012642:Selegiline; D008995:Monoamine Oxidase; D003010:Clorgyline