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In vitro GABA‐transaminase inhibitory compounds from the root of Angelica dahurica
Author(s) -
Choi Soo Young,
Ahn EunMi,
Song MyoungChong,
Kim Dae Won,
Kang Jeong Han,
Kwon OhShin,
Kang TaeCheon,
Baek NamIn
Publication year - 2005
Publication title -
phytotherapy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.019
H-Index - 129
eISSN - 1099-1573
pISSN - 0951-418X
DOI - 10.1002/ptr.1424
Subject(s) - imperatorin , chemistry , gaba transaminase , transaminase , aminobutyric acid , chromatography , phthalide , enzyme , biochemistry , high performance liquid chromatography , organic chemistry , receptor , glutamate decarboxylase
Abstract The 80% aqueous MeOH extracts from the root of Angelica dahurica , found to inhibit the activities of GABA degradative enzymes GABA transaminase (GABA‐T) and succinic semialdehyde dehydrogenase (SSADH), were fractionated using EtOAc, n ‐BuOH and H 2 O. Repeated column chromatography for the EtOAc and n ‐BuOH fractions led to the isolation of two new coumarins, oxypeucedanin hydrate‐3″‐butyl ether and isopraeroside IV along with six known coumarins, isoimperatorin, imperatorin, phellopterin, oxypeucedanin hydrate, nodakenin and 3′‐hydroxymarmesinin, and two polyacetylenes, falcarindiol and octadeca‐1,9‐dien‐4,6‐diyn‐3,8,18‐triol. Of the isolated pure compounds, imperatorin and falcarindiol inactivated the GABA‐T activities in both time‐ and concentration‐dependent manners. The kinetic studies showed that imperatorin and falcarindiol reacted with the GABA‐T with a second‐order rate constant of 2.3 ± 0.2 m m −1 min −1 and 1.5 ± 0.1 m m −1 min −1 , respectively. It is postulated that imperatorin and falcarindiol are able to elevate the neurotransmitter GABA levels in the central nervous system by an inhibitory action on the GABA degradative enzyme GABA‐T. Copyright © 2005 John Wiley & Sons, Ltd.