Search results for "Complementary"

Flavonoids and Others Constituents from Onopordon macracanthum.

1987

10-Oximeguanacone, the First Nitrogenated Acetogenin Derivative Found To Be a Potent Inhibitor of Mitochondrial Complex I

1998

A new 10-keto bis-tetrahydrofuran acetogenin, guanacone (1), has been isolated from a cytotoxic extract of Annona aff. spraguei seeds. The 10-oximeguanacone derivative 1f is the first bioactive nitrogenated acetogenin found to be a very potent inhibitor of complex I. In addition, a SAR study of guanacone analogues is reported based on the titration of the NADH oxidase and NADH:ubiquinone oxidoreductase activities.

Antiasthmatic acetophenones - an in vivo study on structure activity relationship.

1994

The recently isolated acetophenone glucoside androsin, as the major antiasthmatic principle of Picrorhiza kurroa Royle ex Benth. (Scrophulariaceae), was used as a lead compound for detailed structure-activity relationship studies. More than 25 synthesized or commercially available acetophenones with modified substitution patterns were screened in the Plethysmographic guinea pig model using PAF and/or ovalbumin as challenging agents for the generation of bronchial constriction. Whereas the aglycones in most cases were more effective than the corresponding glycosides, substitution patterns in position 3 and 4 of the phenyl ring and the keto function attached to the phenyl ring were found to b…

Triterpene Saponins from the Roots of Achyranthes bidentata

2001

Three saponins, oleanolic acid-28- O -s-D-glucopyranoside (1), chikusetsusaponin V (2), and 3- O -s-D-glucopyranosyl-oleanolic acid-28- O -s-D-glucopyranoside (3) were isolated from the roots of Achyranthes bidentata Blume (Amaranthaceae). No activity was shown in the granulocyte phagocytosis test nor in the test of the potentiation of the cytotoxicity of cisplatin in human colon cancer cells. This is the first report of compounds 1, 2 and 3 isolated from Achyranthes species. Furthermore, the NMR data of 2 completed the partially published data.

Triterpene Saponins from Wisteria floribunda “macrobotrys” and “rosea”

2017

Five oleanane-type saponins were isolated from two cultivars of Wisteria floribunda (Willd.) DC. (Fabaceae): From the roots of Wisteria floribunda “macrobotrys”, one new oleanane derivative elucidated as 3- O-β-D-xylopyranosyl-(1→2)-β-D-glucuronopyranosyl-22- O-acetyl-3p,22p,24-trihydroxyolean-12-en-30-oic acid, and two known glycosides, and from the roots of Wisteria floribunda “rosea”, two known ones. Their structures were elucidated by a detailed 600 MHz NMR analysis including 1D and 2D NMR (1H, 13C, COSY, TOCSY, ROESY, HSQC, HMBC) experiments and mass spectrometry. Chemotaxonomic conclusions were proposed.

Cycloartane-type Glycosides from Two Species of Astragalus (Fabaceae)

2009

Three known cycloartane-type glycosides were isolated from the roots of two different species of Astragalus, A. glycyphyllos, A. sempervirens. The identification of these compounds were mainly achieved by 2D NMR spectroscopic techniques and FAB-MS. The results of our studies confirm that triterpene saponins from the cycloartane-type skeleton might be chemotaxonomically significant to the genus Astragalus.

Phytochemistry of Weigela x “kosteriana variegata” (Caprifoliaceae)

2018

One new triterpene glycoside 3- O-β-D-xylopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→3)]-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyloleanolic acid, was isolated from Weigela x “kosteriana variegata” (Caprifoliaceae), with three known ones. Their structures were characterized by a combination of mass spectrometry and 1D and 2D NMR spectrocopic techniques including 1H- and 13C NMR, COSY, TOCSY, NOESY, HSQC, and HMBC experiments. The toxicological properties of some glycosides were determined with a zebrafish-based assay. The results show that the most active compounds were toxic to the larvae in the range of 1 μM.

Enzymatic formation of the sarpagan-bridge: a key step in the biosynthesis of sarpagine- and ajmaline-type alkaloids.

1995

The glucoalkaloid strictosidine has been converted under cell-free conditions into 10-deoxysarpagine (= normacusine B) in the presence of a crude soluble enzyme extract and microsomal protein isolated from cell suspensions of Rauwolfia serpentina. The enzymatic formation of this alkaloid bearing the C-5/C-16 bond (sarpagan-bridge), which is characteristic for all sarpagine- and ajmaline-type alkaloids, is dependent on NADPH and oxygen. Inhibition studies indicate that for the synthesis of 10-deoxysarpagine a cytochrome P450 dependent monoxygenase is necessary.

Analysis of Essential Oil from Teucrium maghrebinum Greuter et Burdet Growing Wild in Algeria

2009

The chemical composition of the essential oil obtained from aerial parts of Teucrium maghrebinum growing wild in Algeria was analyzed by GC and GC-MS. Among the 66 identified compounds, δ-cadinene (12.7%), germacrene D (11.4%), γ-cadinene (9.5%) and 4-vinyl guaiacol (4.0%) were the most abundant. The oil is strongly characterized by the presence of sesquiterpenes (61.5%), particularly hydrocarbon sesquiterpenes (49.6%).

Steroidal saponins from Chlorophytum deistelianum

2016

Abstract Phytochemical investigation of the aerial parts of Chlorophytum deistelianum led to the isolation of four previously undescribed steroidal saponins called chlorodeistelianosides A–D with five known ones. Their structures were established mainly by extensive 1D and 2D NMR spectroscopic techniques and mass spectrometry as (25R)-3β-[(β- d -glucopyranosyl-(1 → 3)-[α- l -rhamnopyranosyl-(1 → 4)]-β- d -xylopyranosyl-(1 → 3)-[β- d -glucopyranosyl-(1 → 2)]-β- d -glucopyranosyl-(1 → 4)-β- d -galactopyranosyl)oxy]-5α-spirostan-12-one, (24S,25S)-24-[(β- d -glucopyranosyl)oxy]-3β-[(β- d -glucopyranosyl-(1 → 2)-[β- d -xylopyranosyl-(1 → 3)]-β- d -glucopyranosyl-(1 → 4)-β- d -galactopyranosyl)ox…