| 1. |
|
|
| 2. |
- Weimann, C, et al.
(författare)
-
Spasmolytic effects of baccharis conferta and some of its constituents
- 2002
-
Ingår i: Journal of Pharmacy and Pharmacology (JPP). - : Oxford University Press (OUP). - 0022-3573 .- 2042-7158. ; 54:1, s. 99-104
-
Tidskriftsartikel (refereegranskat)abstract
- The Nahua of the Mexican state of Veracruz use Baccharis conferta in the treatment of a variety of gastrointestinal illnesses, especially diarrhoea associated with gastrointestinal cramps. The aerial parts of B. conferta were investigated phytochemically and pharmacologically using the guinea pig ileum assay as a model (histamine, KCI and electric stimulation). The crude ethanolic extract showed a dose-dependent antispasmodic effect that was particularly strong in flavonoid-rich fractions (e.g. IC50 value for fraction E.3.1 from the ethyl acetate fraction, in histamine-induced contraction, 10 microg mL(-1)). Several flavonoids (apigenin-4',7-dimethylether, naringenin-4',7-dimethylether, pectolinarigenin and cirsimaritin) were isolated, while others were identified in complex fractions by GC-MS. The flavonoids play an important role in the antispasmodic activity of this indigenous drug. Additionally, oleanolic acid and its methyl ester as well as erythrodiol were isolated. Oleanolic acid methyl ester shows weak antibacterial activity against M. luteusand E. coli (20 microg/spot in a TLC assay). The phytochemical as well as the pharmacological data provide some in-vitro evidence forthe use of B. conferta in thetreatment of gastrointestinal cramps.
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Broussalis, Adriana M., et al.
(författare)
-
First cyclotide from Hybanthus (Violaceae)
- 2001
-
Ingår i: Phytochemistry. - : Elsevier. - 0031-9422 .- 1873-3700. ; 58:1, s. 47-51
-
Tidskriftsartikel (refereegranskat)abstract
- Hypa A, a novel macrocyclic polypeptide containing 30 amino acid residues, has been isolated from the n-butanol extract of the Argentine plant Hybanthus parviflorus. The sequence, cyclo-(SCVYIPCTITALLGCSCKNKVCYNGIPCAE), was determined by automated Edman degradation, quantitative amino acid analysis and nanospray MS/MS2. Three intramolecular disulfide bridges stabilize the cyclic peptide backbone of hypa A. Using these structural features to classify the peptide as a cyclotide, we extended the distribution of that substance class to a new genus, and now propose a uniform nomenclature for cyclotides.
|
|
| 6. |
- Burman, Robert, 1979-, et al.
(författare)
-
Evaluation of toxicity and anti-tumour activity of cycloviolacin O2 in mice.
- 2010
-
Ingår i: Biopolymers. - : Wiley. - 0006-3525 .- 1097-0282. ; 94:5, s. 626-634
-
Tidskriftsartikel (refereegranskat)abstract
- Cycloviolacin O2 is a small cyclic cysteine-rich protein belonging to the group of plant proteins called cyclotides. This cyclotide has been previously shown to exert cytotoxic activity against a variety of human tumor cell lines as well as primary cultures of human tumor cells in vitro. This study is the first evaluation of its tolerability and antitumor activity in vivo. Maximal-tolerated doses were estimated to 1.5 mg/kg for single intravenous (i.v.) dosing and 0.5 mg/kg for daily repeated dosing, respectively. Two different in vivo methods were used: the hollow fiber method with single dosing (i.v. 1.0 mg/kg) and traditional xenografts with repeated dosing over 2 weeks (i.v. 0.5 mg/kg daily, 5 days a week). The human tumor cell lines used displayed dose-dependent in vitro sensitivity (including growth in hollow fibers to confirm passage of cycloviolacin O2 through the polyvinylidene fluoride fibers), with IC50 values in the micromolar range. Despite this sensitivity in vitro, no significant antitumor effects were detected in vivo, neither with single dosing in the hollow fiber method nor with repeated dosing in xenografts. In summary, the results indicate that antitumor effects are minor or absent at tolerable (sublethal) doses, and cycloviolacin O2 has a very abrupt in vivo toxicity profile, with lethality after single injection at 2 mg/kg, but no signs of discomfort to the animals at 1.5 mg/kg. Repeated dosing of 1 mg/kg gave a local-inflammatory reaction at the site of injection after 2–3 days; lower doses were without complications.
|
|
| 7. |
|
|
| 8. |
- Claeson, Dick
(författare)
-
U-Pb zircon age of metagranite with relict phenocryst texture at Linavare, map sheet 27K Nattavaara, Norbotten county
- 2018
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Norrbotten, Sweden is a key area of Europe for future exploration and mining. To establish age relations for magmatic activity and metamorphic overprinting in this area, the sampled rock was selected (Fig. 1, 2, 21). This rock occurs at Linavare as mega-xenoliths of strongly deformed, foliated, recrystallised and low-radiation metagranite in massive subvolcanic granite to rhyolite porphyry that was age determined to 1870 ± 6 Ma, giving a lower age of the high-grade metamorphic event (this issue). The age of the regional metamorphic event may be deduced from the age of these two rocks, occurring between their igneous crystallisation ages. Determine the magmatic age of the metagranite is the main aim and if the zircon display metamorphic rims or overgrowths, these should be studied too.
|
|
| 9. |
|
|
| 10. |
- Claeson, Per, et al.
(författare)
-
Calcium Antagonistic Properties of the Sesquiterpene T‐Cadinol : A Comparison with Nimodipine in the Isolated Rat Aorta
- 1991
-
Ingår i: Pharmacology and Toxicology. - : Wiley. - 0901-9928 .- 1600-0773. ; 69:3, s. 173-177
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract: (+)‐T‐Cadinol is a sesquiterpene with smooth muscle relaxing properties. In the isolated rat aorta, T‐cadinol relaxed contractions induced by 60 mM K+ in a concentration‐dependent fashion. The dihydropyridine calcium antagonist nimodipine was approximately 4,000 times more potent than T‐cadinol. While both drugs nearly abolished the K+‐induced contractions, they only partially relaxed contractions induced by phenylephrine. The relaxation induced by T‐cadinol and nimodipine in K+‐contracted aortic rings, was completely reversed by the calcium channel activator Bay K8644. In aortic preparations partially depolarized by 20 mM K+, Bay K8644 induced a concentration‐dependent contraction. Nimodipine shifted the Bay K8644 concentration‐response curve to the right in a parallel manner, consistent with a competitive mode of inhibition. T‐cadinol at concentrations less than 10−3.5 M also produced a right‐ward shift of the Bay K8644 concentration‐response curve with a maintained maximum response. However, the highest T‐cadinol concentration used (10−3.5 M) significantly reduced the maximum response. In conclusion, although T‐cadinol and nimodipine display marked structural differences, their pharmacological profiles of action have several features in common, suggesting that T‐cadinol is a calcium antagonist, possibly interacting with the dihydropyridine binding sites on the calcium channels. 1991 Nordic Pharmacological Society
|
|
