Flavonoids from Acalypha indica.
Four known kaempferol glycosides, mauritianin, clitorin, nicotiflorin and biorobin, have been isolated from the flowers and leaves of Acalypha indica. Some formerly published NMR data were corrected.
Euphorbiaceae↗
Biomedical subjects
A Nahrstedt
Publications and source records attributed to A Nahrstedt.
5-HT3 receptor blocking activity of arylalkanes isolated from the rhizome of Zingiber officinale.
Different extracts (ethanolic, hexane, aqueous) of ginger (rhizomes of Zingiber officinale) and the essential oil were tested using [14C]guanidinium influx into N1E-115 cells and the isolated rat ileum in order to identify their activity in inhibiting 5-HT3 receptor function. The hexane extract proved to be the most active and yielded upon bioassay-guided fractionation nine constituents: [6]-, [8]-, [10]-gingerols, [6]- and [8]-shogaols which were previously shown as active in vivo against cytotoxic drug-induced emesis; [4]-gingerol, [6]-gingerdiol, diacetyl-[6]-gingerdiol and [6]-dehydrogingerdione have not been previously tested for anti-emetic or 5-HT3 receptor antagonistic effects. Even though the latter four compounds are only minor constituents, their identification contributed towards the characterisation of a structure-activity relationship of this class of compounds. The order of potency for the nine constituents in the N1E-115 cell system was [6]-gingerdiol approximately diacetyl-[6]-gingerdiol approximately [6]-dehydrogingerdione approximately [6]-shogaol > or = [8]-shogaol approximately [8]-gingerol > [10]-gingerol > or = [6]-gingerol > [4]-gingerol.
Animals↗
Plasma levels of hypericin in presence of procyanidin B2 and hyperoside: a pharmacokinetic study in rats.
The biological evaluation of hypericin in various test models is hampered by its poor water solubility. In former studies we have shown that the water solubility of hypericin was remarkably enhanced in the presence of the procyanidins or flavonol glycosides of Hypericum extract. The present pharmacokinetic study was designed to find out whether the improved water solubility in the presence of procyanidin B2 or hyperoside is correlated to increased plasma levels of hypericin. Plasma levels of hypericin in rats in the presence and absence of procyanidin B2 or hyperoside were determined by reversed phase HPLC using fluorimetric detection. Both compounds increased the oral bioavailability of hypericin by ca. 58 % (B2) and 34 % (hyperoside). Procyanidin B2 and hyperoside had a different influence on the plasma kinetics of hypericin; median maximal plasma levels of hypericin were detected after 360 min (C max : 8.6 ng/mL) for B2, and after 150 min (C max : 8.8 ng/mL) for hyperoside. It can be speculated that, when administered together with these compounds, a significant accumulation of hypericin in rat plasma in the presence of both polyphenols might be responsible for the observed increased in vivo activity.
Administration, Oral↗
Dissolution, solubility and cooperativity of phenolic compounds from Hypericum perforatum L. in aqueous systems.
The dissolution in water of phenolic constituents of St. John's wort (Hypericum perforatum L.) from a medicinal tea and a coated tablet formulation showed different dissolution profiles. In general, the flavonoid glycosides were well dissolved, followed by flavonoid aglycones and hypericin while hyperforin was only detectable at a very low level. Interestingly, hypericin exhibited much better extraction and dissolution rates than the similarly lipophilic hyperforin. When determining the octanol/water partition coefficient it became obvious that the solubility of pure hypericin in water increased upon addition of some phenolic constituents typical for Hypericum extracts. Most effective in solubilizing hypericin was hyperoside (hyperin, quercetin 3-O-beta-D-galactoside) which increased the concentration of hypericin in the water phase up to 400 fold in this model.
Anthracenes↗
Prodelphinidin trimers and characterization of a proanthocyanidin oligomer from Cistus albidus.
Two new natural prodelphinidin trimers have been isolated from the air-dried herb of Cistus albidus, epigallocatechin-(4beta --> 8)-gallocatechin-(4alpha --> 8)-catechin and epigallocatechin-(4beta --> 8)-gallocatechin-(4alpha --> 8)-gallocatechin in addition to catechin, gallocatechin and thirteen known proanthocyanidins. The structures were determined on the basis of 1D- and reverse 2D-NMR (HSQC, HMBC) experiments of their peracetylated derivatives, MALDI-TOF-MS and by acid-catalysed degradation with phloroglucinol. A more abundant higher oligomeric proanthocyanidins fraction was also isolated and its chemical constitution studied by 13C-NMR. The mean molecular weight of the higher oligomeric fraction was estimated to be 6-7 flavan-3-ol-units.
Anthocyanins↗
[Piper methysticum (kava) under discussion: observations on quality, effectiveness and safety].
Worldwide the application for a drug registration follows three basic principles: the proof of quality, efficacy and safety. In the following the applicability of these three principles on extracts from roots of the medicinal plant Kava (Piper methysticum) will be examined in the light of the current discussion of possible hepatic side effects ratio.
Adverse Drug Reaction Reporting Systems↗
Gynocardin and cyclopentenylglycine in Rawsonia lucida.
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Journal Article↗
Procyanidins from the herb of Hypericum perforatum.
From the aqueous acetone extract of the herb of Hypericum perforatum the flavanols catechin (1) and epicatechin (2), and the procyanidins A2 (9), B1 (3), B2 (4), B3 (5), B5 (6), B7 (7) and C1 (8) were isolated. Their structures were established as their peracetate derivatives, on the basis of chemical and spectral evidence. The 13C NMR spectrum of the higher molecular weight polymer fraction revealed a 3',4'-dihydroxylated B-ring oxidation pattern and the 2,3-cis relative stereochemistry of the constituent flavan-3-ol units. The mean average molecular size of the polymers was estimated to be 4 to 5 flavan-3-ol units. The procyanidin pattern in comparison to that of Crataegus spec. is briefly discussed.
Antioxidants↗
Flavonoids from Hypericum perforatum show antidepressant activity in the forced swimming test.
It has been shown recently that a flavonoid fraction (fraction II) obtained from a crude extract of Hypericum perforatum (St. John's Wort) was remarkably active in the forced swimming test (FST). Fraction II was further separated using MLCCC to give fractions IIa and IIb. Both fractions proved to be active in the FST at different dosages. Further separation of fraction IIa by preparative HPLC yielded fraction IIa1 which mainly was composed of hyperoside, isoquercitrin, miquelianin and quercitrin, and fraction IIa2 which contained small amounts of hyperoside and astilbin, while most compounds were not known. Both fractions were active after acute treatment in the FST. Isolates obtained from these fractions including hyperoside, isoquercitrin, quercitrin, miquelianin, the aglycone quercetin and astilbin, were tested for activity in the FST. Except for quercetin, quercitrin and astilbin all compounds were active. To exclude false positive results in the FST the validity was checked in open field experiments and in the FST after 12 days of daily treatment.
Animals↗
Inhibition of neutrophil elastase activity by cinnamic acid derivatives from Cimicifuga racemosa.
Caffeic acid, fukinolic acid as well as cimicifugic acids A, B, E and F isolated from the rhizomes of Cimicifuga racemosa (Ranunculaceae) inhibited the activity of neutrophil elastase (EC 3.4.21.37) in a dose-dependent manner. An IC50 of 93 mumol/L was determined for caffeic acid and 0.23 mumol/L for fukinolic acid. Cimicifugic acid A inhibited the enzyme with an IC50 of 2.2 mumol/L, cimicifugic acid B with 11.4 mumol/L, and cimicifugic acid F with 18 mumol/L. Cimicifugic acid E was only a very weak inhibitor.
Cinnamates↗
Fukiic and piscidic acid esters from the rhizome of Cimicifuga racemosa and the in vitro estrogenic activity of fukinolic acid.
Hydroxycinnamic acid esters of fukiic acid and piscidic acid were isolated from a 50% ethanolic extract obtained from the rhizomes of Cimicifuga racemosa (Ranunculaceae). Besides 2-E-caffeoylfukiic acid (fukinolic acid), 2-E-feruloylfukiic acid (cimicifugic acid A), 2-E-isoferuloylfukiic acid (cimicifugic acid B), 2-E-feruloylpiscidic acid (cimicifugic acid E) and 2-E-isoferuloylpiscidic acid (cimicifugic acid F), free caffeic, ferulic and isoferulic acids were isolated. The estrogenic activity of fukinolic acid was shown by increased proliferation (126% at 5 x 10(-8) M) of an estrogen dependent MCF-7 cell system with reference to estradiol (120% at 10(-10) M).
Esters↗
New pyrazole alkaloids from the root bark of Newbouldia laevis.
The root bark of Newbouldia laevis afforded withasomnine, 4'-hydroxywithasomnine, 4'-methoxywithasomnine, newbouldine, 4'-hydroxynewbouldine, and 4'-methoxynewbouldine. 4'-Methoxywithasomnine and 4'-methoxynewbouldine are new natural products.
Alkaloids↗
Solubilized hypericin and pseudohypericin from Hypericum perforatum exert antidepressant activity in the forced swimming test.
It has been shown recently that the fraction IIIc of a crude extract of Hypericum perforatum, (St. John's wort) that contained both hypericin (1) and pseudohypericin (2), was remarkably active in the rats forced swimming test (FST) after Porsolt. However, neither of the naphthodianthrones isolated from this fraction were sufficiently effective when administered suspended in water. The solubility of 1 and 2 is remarkably increased in the presence of a fraction containing procyanidins, especially procyanidin B2, which is present also in the active Hypericum fraction IIIc. The cooperative effect of procyanidins significantly increased the in vivo effects of 1 and 2, which exhibited inverted U-shaped dose response curves, in the FST. The anti-immobility effect of solubilized 1 and 2 was antagonized by the dopamine antagonist sulpiride. These data indicate that naphthodianthrones are antidepressant constituents of H. perforatum and suggest that the dopaminergic system is involved in their action.
Animals↗
In vitro antispasmodic compounds of the dry extract obtained from Hedera helix.
Commercial dry extract of Hedera helix L. is used for the treatment of disorders of the respiratory tract; it is standardized towards papaverine (papaverine equivalent value, PE, activity of 1 g test substance equivalent to the activity of x mg papaverine) by in vitro antispasmodic activity on isolated guinea-pig ileum with acetylcholine as spasmogen. In order to determine the phytochemical basis for the antispasmodic activity, bioassay guided fractionation and subsequent isolation of phenolic compounds (flavonols, caffeoylquinic acids) and saponins (hederacoside C, alpha-hederin, hederagenin) was carried out. Fractions and isolates obtained were investigated for antispasmodic activity and their contribution to the activity of the extract was calculated. Significant activity was found for both saponins and phenolic compounds, the PE values being approx. 55 and 49 for alpha-hederin and hederagenin, 54 and 143 for quercetin and kaempferol, and 22 for 3,5-dicaffeoylquinic acid, respectively. In view of their relative high concentration the saponins contribute most to the anti-spasmodic activity, followed by dicaffeoylquinic acids and the flavonol derivatives. The results indicate that the summed PE value of the compounds mentioned is an acceptable agreement with the PE value of the whole extract determined biologically.
Animals↗
Effects of the total extract and fractions of Hypericum perforatum in animal assays for antidepressant activity.
A commercially available extract of the aerial parts of Hypericum perforatum, LI 160, showed pronounced activity in selected animal bioassays. These include the forced swimming test (FST) and the tail suspension test, used to determine antidepressant activity, and tests indicating activity on the central nervous system, such as body temperature and ketamine induced sleeping time. The counteracting effects of drugs known to interfere with the central dopaminergic system strongly suggested that dopamine mediated activity is important for the activity of the extract. Dose-response experiments of the total extract and of fractions rich in flavonoids and napthodianthrones produced inverted U-shaped dose response curves.
Animals↗
Biologically active and other chemical constituents of the herb of Hypericum perforatum L.
Phenylpropanes, flavonol derivatives, biflavones, proanthocyanidins, xanthones, phloroglucinols, some amino acids, naphthodianthrones and essential oil constituents are the natural plant products known from the crude drug of Hypericum perforatum, Hyperici herba. These compounds are discussed with respect to structural features, their concentration, biological activities and their possible contribution to the clinically demonstrated antidepressant efficacy of extracts obtained from Hyperici herba.
Animals↗
Nai habarala (Alocasia cucullata) fruits; analysed for potential hydrogen cyanide.
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Foodborne Diseases↗
Reduction of ACh-induced contraction of rat isolated ileum by coptisine, (+)-caffeoylmalic acid, Chelidonium majus, and Corydalis lutea extracts.
The crude extracts of Chelidonium majus and Corydalis lutea were examined for antispasmodic activity against acetylcholine (ACh)-induced contraction on isolated rat ileal smooth muscle. Further, coptisine and caffeolmalic acid as components of the alkaloid and the hydroxycinnamic acid ester fraction of both plants were similarly investigated. The ACh-induced contraction was found to be antagonized weakly by caffeolymalic acid (6.9%; 2.5 x 10(-5) g/ml/organ bath), C. majus extract (12.7%; 2.0 x 10(-4) g/ml), and a higher concentration of coptisine (16.5%; 1.0 x 10(-5) g/ml) whereas the antispasmodic activity of C.lutea extract reached 45% (2.0 x 10(-4) g/ml). Antagonism by papaverine as a positive control amounted to 83.2%.
Acetylcholine↗