Scoparic Acid A, a β-Glucuronidase Inhibitor from Scoparia dulcis

Abstract

The 70% EtOH extract of Scoparia dulcis showed inhibitory activity against beta-glucuronidase from bovine liver. Bioassay-directed fractionation of the active extract led to the isolation of three labdane-type diterpene acids, scoparic acid A [1] [6-benzoyl-12-hydroxy-labda-8(17), 13-dien-18-oic acid], scoparic acid B [2] [6-benzoyl-14,15-dinor-13-oxo-8(17)-labden-18-oic acid], and scoparic acid C [3] [6-benzoyl-15-nor-14-oxo-8(17)-labden-18-oic acid], the structures of which were established by spectral means, including X-ray analysis. Scoparic acid A was found to be a potent beta-glucuronidase inhibitor.

Structure Revision of Caesalpinistas A and B and Isolation of a New Furanoditerpenoid from the Cotyledons of Caesalpinia decapetala var. japonica

“…(Table), were in good agreement with those previously reported for caesalpinista B( 1' ') [ 5].T hese findings indicated that 1 is identical to caesalpinista B. However, the (18 -20) [4] [6] and not for an a-oriented one (28 -29) [7 -9]. These findings suggested that it is necessary to re-examine the configurational assignment as reported for 1' ' [5].A s the 1 H-NMR spectrum of 1 recordedi nC DCl 3 showed partiallyo verlapped signals,1 D-difference NOE experiments were performed in C 6 D 6 .I rradiation of H a ÀC(20) enhanced Me(19)( 6.5%),i ndicating that Me(19)i sa xial and b-oriented.…”

“…Thes pecific optical rotation, UV,e lectronic circular dichroism( ECD), IR, 1 H-and 13 C-NMR,a nd HR-ESI-FT-MS data of the product were identical to those of 3.T hese results suggested 2 to be an acetyl analog of 1.T his assumption was supported by the NMR data of 2 (Table), which were very similar to those of caesalpinista B(1), exceptfor the presence of an additional Ac group in 2.T he significant downfield shift (þ 1.0) of HÀC(6)i n2 indicatedt hat the additional Ac group is linked to the O-atom at C(6). As the 1 H-NMR spectrum of 2 recordedi nC DCl 3 showed partially overlapped signals, extensive NMR recordings were also performed in C 6 D 6 . The 1 H, 1 H-COSY and HMB correlationss hown in Fig.…”

.BETA.-N-Cyanoethyl Acyl Hydrazide Derivatives: A New Class of .BETA.-Glucuronidase Inhibitors.

“…The plates were read on a multiplate reader (spectra MAX-340) at 405 nm. The inhibitory activities were determined as described previously, 7) except that 5 ml each of test compound was dissolved in DMSO, mixed with enzyme, and incubated at 37°C for 15 min before the addition of substrate to start the reaction. The percentage inhibitory activity was calculated as follows: (EϪS)/Eϫ100, where E is the activity of enzyme without test material and S is the activity of enzyme with test material.…”

“…Endogenous biliary bglucuronidase deconjugates the glucuronides of bilirubin and causes the development of cholelithiasis in human bile. 4) Many b-glucuronidase inhibitors such as 8-hydroxytricetin-7-glucuronide and isovitexin, 5) trihydroxy pipecolic acid, 6) and scoparic acid A and C 7) have already been isolated from different plants and some are used clinically.…”

In vivo inhibition of gastric acid secretion by the aqueous extract of Scoparia dulcis L. in rodents

“…Amelin, a compound with anti-diabetic properties (Nath, 1943) and 6-metoxibenzoxazolinone, a depressor of arterial blood pressure (Chen and Chen, 1976;Kawasaki et al, 1987) have also been identified in this species. Inhibition of ␤-glucuronidase by scoparic acid A (Hayashi et al, 1992) and by 8-hydroxytricetin-7-glucuronide (Kawasaki et al, 1988), antiviral activity by scopadulin (Hayashi et al, 1990a) and scopaducilic acid B Hayashi et al, 1992) have been also reported. Previous studies from our laboratory demonstrated analgesic (Freire et al, 1991) and anti-inflammatory (Freire et al, 1993) activities due to the presence of the triterpene glutinol isolated from its ethanolic crude extract.…”