Blood-pressure lowering, positive chronotropy and inotropy by the Veratrum alkaloids germidine and germerine but negative chronotropy by veratridine in mice

Germidine and germerine, the Veratrum alkaloids lowered blood pressure accompanied with positive chronotropy and inotropy in mice. Germerine was more potent than germidine in both blood-pressure lowering and positive inotropy, whereas veratridine produced negative chronotropy and positive inotropy. An acyl group (an acetyl or a 2-methylbutyroyl group) at 3-O-R¹ position and a 2-methylbutyroyl group at 15-O-R² position in germine were important to produce the positive inotropy and chronotropy. The presence of a veratroyl group at 3-O-R¹ position and a free hydroxyl group at 15-O-R² position may be essential to produce the negative chronotropy by veratridine. The positive inotropy by germidine and veratridine may be due to TTX-resistant Na⁺ channel activation.     

Immunohistochemical and functional studies for M3 muscarinic receptors and cyclo‐oxygenase‐2 expressed in the mouse atrium

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N6-苯甲酰基-2'-叔丁基二甲基硅氧基腺苷-3'-H-膦酸的合成工艺研究

目的 研究N~6-苯甲酰基-2′-叔丁基二甲基硅氧基腺苷-3′-H-膦酸的合成工艺。方法 以腺苷为起始原料,先对腺苷的嘌呤氨基进行苯甲酰基保护,再分别向腺苷的5′位和2′位引入二甲氧基三苯甲基(DMT)和叔丁基二甲基硅基(TBDMS)保护基,制备得到关键中间体N~6-苯甲酰基-5′-二甲氧基三苯甲氧基-2′-叔丁基二甲基硅氧基腺苷(3)。中间体3与磷试剂2-氯-4H-1,3,2-苯并二氧磷杂环己烷-4-酮反应引入膦酸基团,最后使用二氯乙酸脱除DMT保护基得到目标产物。结果 经过5步反应得到了目标化合物N~6-苯甲酰基-2′-叔丁基二甲基硅氧基腺苷-3′-H-膦酸,并利用~1H-NMR、~(31)P-NMR、质谱等方法确证了其结构。本合成工艺的总收率为35.7%,目标化合物的质量分数为98.5%。结论 该合成工艺与原有方法相比步骤短,操作简单,具有良好的应用前景。     

Isolation and characterization of cytotoxic compounds from Euphorbia cornigera Boiss.

Methanolic extract of Euphorbia cornigera shoots was separated using HPLC, affording compounds 1–4. Their structures and relative stereochemistry were established after obtaining their spectroscopic (IR, ¹H, ¹³C NMR COSY-45°, HOHAHA, HSQC, HMBC, NOESY, and mass measurement) data. On the basis of these data, the compounds were characterized as 3-O-(2,3-dimethylbutanoyl)-13-O-dodecanoyl-20-O-tetradecanoylingenol (1), 3-O-decanoyl-20-O-hexanoylingenol (2), 3-O-(2,3-dimethylbutanoyl)-13-O-dodecanoyl-20-O-hexadecanoylingenol (3), and 13-O-dodecanoyl-20-O-hexanoylingenol (4); among these compounds, two (1 and 2) were new metabolites while the rest (3 and 4) were known. The MTT cytotoxicity assay was carried out using amrubicin hydrochloride as a positive control. Compound 1 displayed IC₅₀ as 5.0 and 2.9 μM against RAW and HT-29 cell lines, respectively, which is 5- and 1.5-folds stronger than the control with IC₅₀ values of 25 and 4.36 μM, respectively.     

Biotransformation of oleanolic acid by Alternaria longipes and Penicillium adametzi

Microbial transformation of oleanolic acid (1) was carried out. Six transformed products (2–7) from 1 by Alternaria longipes and three transformed products (8–10) from 1 by Penicillium adametzi were isolated. Their structures were elucidated as 2α,3α,19α-trihydroxy-ursolic acid-28-O-β-d-glucopyranoside (2), 2α,3β,19α-trihydroxy-ursolic acid-28-O-β-d-glucopyranoside (3), oleanolic acid 28-O-β-d-glucopyranosyl ester (4), oleanolic acid-3-O-β-d-glucopyranoside (5), 3-O-(β-d-glucopyranosyl)-oleanolic acid-28-O-β-d-glucopyranoside (6), 2α,3β,19a-trihydroxy-oleanolic acid-28-O-β-d-glucopyranoside (7), 21β-hydroxyl oleanolic acid-28-O-β-d-glucopyranoside (8), 21β-hydroxyl oleanolic acid (9), and 7α,21β-dihydroxyl oleanolic acid (10) based on the extensive NMR studies. Among them, 10 was a new compound and compounds 5 and 8–10 had stronger cytotoxic activities against Hela cell lines than the substrate. At the same time, it was reported for the first time in this paper that the skeletons of compounds 2 and 3 were changed from oleanane to uranane and seven glycosidation products were obtained by biotransformation.     

Kaempferol glycosides with antioxidant activity from <Emphasis Type="Italic">Brassica juncea</Emphasis>

From the leaves of Brassica juncea, three kaempferol glycosides, kaempferol-3-O-(2-O-sinapoyl)-β-d-glucopyranosyl-(1→2)-β-d-glucopyranoside-7-O-β-d-glucopyranoside (1), kaempferol-3-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranoside-7-O-β-d-glucopyranosyl-(1→6)-β-d-glucopyranoside (2), and kaempferol-3-O-(2-O-sinapoyl)-β-d-glucopyranosyl-(1→2)-β-d-glucopyranoside-7-O-β-d-glucopyranosyl-(1→6)-β-d-glucopyranoside (3) were isolated and the structures elucidated on the basis of spectral and chemical evidences. Antioxidant activities were determined by measuring the scavenging activities on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and peroxynitrite (ONOO⁻). Compounds 1 and 3 showed good antioxidant activities with respective IC₅₀ values of 28.61 and 36.93 μM toward DPPH; respective IC₅₀ values of 9.79 and 11.40 μM toward ONOO⁻. However, compound 2 showed no DPPH scavenging activity and weak ONOO⁻ scavenging activity with an IC₅₀ value of 32.00 μM.     

Influence of eicosanoids on serotonin release in the rat brain: inhibition by prostaglandins E1 and E2

Summary Cardiac alpha- and beta-adrenoceptor sensitivities were examined after chronic pretreatment of rats with reserpine. Increases in sensitivity would indicate that the receptor is under the influence of the sympathetic innervation, removal by catecholamine depletion with reserpine of the tonic effect of neurotransmitter release would permit receptor upregulation. The positive inotropic responses of paced left atria and papillary muscles and the positive chronotropic responses of spontaneously beating right atria were recorded. A concentration-response curve to isoprenaline (beta-adrenoceptor-mediated) was followed, in the presence of beta-blockade, by one to methoxamine (alpha-adrenoceptor-mediated). Methoxamine exerted positive inotropy of left atria and papillary muscles, the maxima being 43.2 ± 2.7 and 26.8 ± 4.4% of the isoprenaline maxima. A small positive chronotropy (16.5 ± 5.6% maximum) of right atria occurred. After pretreatment with reserpine (1.0 mg kg^–1 i.p. daily) for 7 days, the three preparations displayed supersensitivity to isoprenaline, revealed as a significant displacement (P < 0.05) of the concentration-response curves to the left of those for control rats. Reserpine pretreatment, however, had no effect on the sensitivity to methoxamine. The increase in beta-adrenoceptor sensitivity to isoprenaline after reserpine pretreatment was accompanied by a significant 41.3% increase (P < 0.05) in the number of [³H]-dihydroalprenolol ([³H]-DHA) binding sites (B _max) in ventricular membranes, although the dissociation constant (_{K D}) was unaffected. There were more alpha-adrenoceptor [³H]-prazosin binding sites in ventricular than atrial membranes. However, there was no difference in K _D or B _max between reserpine-pretreated and control tissues. It is proposed that the increase in beta-adrenoceptor sensitivity and binding sites arises from the depletion-induced loss of neuronal noradrenaline release onto the beta-adrenoceptors which are therefore directly under the influence of the neurotransmitter. The failure of cardiac alpha-adrenoceptors to exhibit supersensitivity and increased numbers suggests that they are not directly affected by the sympathetic innervation. Send offprint requests to K. J. Broadley at the above address     

Calcium Channel Blockade: Central Hemodynamic Effects

Abstract: Despite differences in vasodilatation, inotropy and chronotropy between verapamil, nifedipine and diltiazem when tested in vitro, these drugs will produce similar central hemodynamic effects in healthy young or middle-aged individuals, provided they are given in equipotent doses. The individual profiles of hemodynamic action of these calcium channel blockers are briefly reviewed and discussed.     

A potential inhibitor of rat aortic vascular smooth muscle cell proliferation from the pollen of <Emphasis Type="Italic">Typha angustata</Emphasis>

By various chromatographic methods, three flavonoids, (2S)-naringenin (1), isorhamnetin 3-O-(2-O-α-l-rhamnopyranosyl) β-d-glucopyranoside (2), typhaneoside (3), and two sterol glycosides, β-sitosterol-3-O-(6-octadecanoyl) β-d-glucopyranoside (4) and β-sitosterol-3-O-(6-octadeca-9Z,12Z-dienoyl) β-d-glucopyranoside (5), were isolated from the pollen of Typha angustata. Their structures were determined on the basis of spectroscopic analyses. The flavonoids (1–3) were evaluated for their effects on the viability and proliferation of rat aortic smooth muscle cells. (2S)-naringenin (1) significantly inhibited cell proliferation in a dose-dependent manner without cytotoxic at concentrations of 30, and 50 μM; it reduced the number of cells following PDGF-BB treatment to 1.83 ± 0.30 × 10⁴ and 2.20 ± 0.60 × 10⁴ cells/well, respectively. These findings suggest that (2S)-naringenin has antiproliferative effects on aortic smooth muscle cells.     

Intracellular mechanisms and receptor types for endothelin-1-induced positive and negative inotropy in mouse ventricular myocardium

We examined the intracellular mechanisms for endothelin-1-induced positive and negative inotropic components that coexist in the mouse ventricular myocardium using isolated ventricular tissue and myocytes from 4-week-old mice. In the presence of SEA0400, a specific inhibitor of the Na⁺–Ca²⁺ exchanger, endothelin-1 produced positive inotropy. Endothelin-1, when applied to cardiomyocytes in the presence of SEA0400, did not change the peak amplitude of the Ca²⁺ transient but increased intracellular pH and Ca²⁺ sensitivity of contractile proteins. On the other hand, in the presence of dimethylamiloride (DMA), a specific inhibitor of the Na⁺–H⁺ exchanger, endothelin-1 produced negative inotropy. In cardiomyocytes, in the presence of DMA, endothelin-1 produced a decrease in peak amplitude of the Ca²⁺ transient. In the presence of both DMA and SEA0400, endothelin-1 produced neither positive nor negative inotropy. Positive inotropy was blocked by BQ-123 and negative inotropy by BQ-788. These results suggested that endothelin-1-induced positive inotropy is mediated by ET_A receptors, activation of the Na⁺–H⁺ exchanger and an increase in intracellular pH and Ca²⁺ sensitivity and that the negative inotropy is mediated by ET_B receptors, activation of the Na⁺–Ca²⁺ exchanger and decrease in Ca²⁺ transient amplitude.     

Water-soluble constituents from the leaves of Ilex oblonga

Four new water-soluble constituents, oblongaroside A (1), oblongar ester A (2), oblongaroside B (3), and oblongaroside C (4), were isolated along with four known compounds: 4-O-β-d-glucopyranosyl-3-hydroxybenzalcohol (5), 7-methoxyl-4-O-β-d-glucopyranosyl-3-hydroxybenzalcohol (6), 4-O-β-d-glucopyranosyl-3-hydroxybenzoic acid (7), and 3,4-dihydroxybenzoic acid (8) from the leaves of Ilex oblonga. Identification of their structures was achieved by 1D and 2D NMR experiments, including ¹H–¹H COSY, NOESY, HMQC, and HMBC methods and FAB mass spectral data.     

Chemical constituents from the leaves of Boehmeria rugulosa with antidiabetic and antimicrobial activities

Three new flavonoid glycosides, named chalcone-6′-hydroxy-2′,3,4-trimethoxy-4′-O-β-d-glucopyranoside (1), isoflavone-3′,4′,5,6-tetrahydroxy-7-O-{β-d-glucopyranosyl-(1 → 3)-α-l-rhamnopyranoside} (2), and isoflavone-3′,4′,5,6-tetrahydroxy-7-O-{β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranosyl-(1 → 3)-α-l-rhamnopyranoside} (3), were isolated from the leaves of Boehmeria rugulosa, together with five known compounds, β-sitosterol, quercetin, 3,4-dimethoxy-ω-(2′-piperidyl)-acetophenone (4), boehmeriasin A (5), and quercetin-7-O-β-d-glucopyranoside. The structures of the isolated compounds were determined by means of chemical and spectral data including 2D NMR experiments. The ethanolic extract of leaves showed significant hypoglycemic activity on alloxan-induced diabetic mice. Glibenclamide, an oral hypoglycemic agent (5 mg/kg, p.o.), was used as a positive control. The ethanolic extract of the plant as well as the isolated compounds 1–3 (25 μg/ml) showed potent antimicrobial activity against two bacterial species (Staphylococcus aureus and Streptococcus mutans) and three fungus pathogens (Microsporum gypseum, Microsporum canis, and Trichophyton rubrum). The activities of the isolated compounds 1–3 have been compared with positive controls, novobiocin, and erythromycin (15 μg/ml).     

Substituted adamantylphthalimides: Synthesis,antiviral and antiproliferative activity

In this study, three groups of adamantylphthalimides, bearing different substituents at the phthalimide moiety, N-(4′-R²)phthalimidoadamantanes ( 1 – 7 ), 3-[N-(4′-R²)phthalimido]-1-adamantanols ( 8 – 10 ), and 3-[N-(4′-R²)phthalimido]adamantane-1-carboxylic acids ( 11 – 15 ), were synthesized and screened against tumor cells and viruses. The most potent compounds are not substituted at the adamantane and bear an OH or NH₂ substituent at the phthalimide (compounds 3 and 5 ). The antiproliferative activities of compounds 3 and 5 are in the micromolar range, much higher than the one of thalidomide. A minor antiviral activity against cytomegalovirus and varicella-zoster virus was found for compounds 3 and 5 , but these compounds lacked selectivity. The results presented are important for the rational design of the next-generation compounds with anticancer and antiviral activities.     

Investigation of 6-O-methyl-scutellarein metabolites in rats by ultra-flow liquid chromatography/quadrupole-time-of-flight mass spectrometry

Context Scutellarin (1) has been widely used in China to treat acute cerebral infarction and paralysis induced by cerebrovascular diseases. However, scutellarin (1) has unstable metabolic characteristics.

Objective The metabolic profile of 6-O-scutellarein was studied to determine its metabolic stability in vivo.

Materials and methods In this study, a method of UFLC/Q-TOF MS was used to study the 6-O-methyl-scutellarein metabolites in rat plasma, urine, bile and faeces after oral administration of 6-O-methyl-scutellarein (3). One hour after oral administration of 6-O-methyl-scutellarein (3) (34?mg/kg), approximately 1?mL blood samples were collected in EP tubes from all groups. Bile, urine and faeces samples were collected from eight SD rats during 0–24?h after oral administration. The mass defect filtering, dynamic background subtraction and information dependent acquisition techniques were also used to identify the 6-O-methyl-scutellarein metabolites.

Results The parent compound 6-O-methyl-scutellarein (3) was found in rat urine, plasma, bile and faeces. The glucuronide conjugate of 6-O-methyl-scutellarein (M1, M2), diglucuronide conjugate of 6-O-methyl-scutellarein (M3), sulphate conjugate of 6-O-methyl-scutellarein (M4), glucuronide and sulphate conjugate of 6-O-methyl-scutellarein (M5), methylated conjugate of 6-O-methyl-scutellarein (M6) were detected in rat urine. M1, M2 and M3 were detected in rat bile. M1 was found in rat plasma and M7 was detected in faeces.

Discussion and conclusion Because the parent compound 6-O-methyl-scutellarein (3) was found in rat urine, plasma, bile and faeces, we speculate that 6-O-methyl-scutellarein (3) had good metabolic stability in vivo. This warrants further study to develop it as a promising candidate for the treatment of ischemic cerebrovascular disease.     

Novel furostanol saponins from the bulbs of Allium macrostemon B. and their bioactivity on [Ca2+]i increase induced by KCl

Chemical reinvestigation of the ethanol extract of the dried bulbs of Allium macrostemon B. led to the isolation of two novel furostanol saponins, named macrostemonoside M (1) and macrostemonoside N (2), together with six known saponins. The structures of new compounds were elucidated on the basis of extensive spectroscopic analysis including 1D and 2D NMR as (25R)-22-hydroxy-5β-furostane-1β,2β,3β,6α-tetraol-26-O-β-d -glucopyranoside and 22-hydroxy-5β-furost-25-(27)-ene-1β,2β,3β,6α-tetraol-26-O-β-d -glucopyranoside, respectively. The pharmacological activities of all the saponins on [Ca²⁺]_i increase induced by KCl were evaluated.     

Two new acetylated flavonoid glycosides from Centaurium spicatum L

Two new acetylated flavonol glycosides, quercetin 3-O-[(2,4-diacetyl-α-l-rhamnopyranosyl)-(1→6)]-2,4-diacetyl-β-d-galactopyranoside (1) and quercetin 3-O-[(2,4-diacetyl-α-l-rhamnopyranosyl)-(1→6)]-3,4-diacetyl-β-d-galactopyranoside (2), in addition to two known acetylated quercetin glycosides quercetin 3-O-[(2,3,4-triacetyl-α-l-rhamnopyranosyl)-(1→6)-β-d-galactopyranoside (3) and quercetin 3-O-[(2,3,4-triacetyl-α-l-rhamnopyranosyl)-(1→6)-3-acetyl-β-d-galactopyranoside (4), were isolated from the aerial part of Centaurium spicatum (L.) Fritsch (Gentianaceae). Structure elucidation, especially the localization of the acetyl groups, and complete ¹H and ¹³C NMR assignments of these biologically active compounds were carried out using one- and two-dimensional NMR measurements, including ¹H- and ¹³C-NMR, DEPT-135, H–H COSY, HMQC and HMBC, in addition to HR-FAB/MS experiments.     

款冬花多糖抗氧化能力测定

目的用流动注射化学发光法探讨中药款冬花多糖的体外抗氧化作用。方法将款冬花多糖提取液加入3种化学发光体系,测量其发光强度,根据系统化学发光被抑制的程度评价款冬花对活性氧自由基的清除能力,并以抗坏血酸（Vc）为阳性对照。结果款冬花多糖对.OH有很好的清除作用,对O2.、H2O2也有一定的清除作用,且在0.25～4.4 mg.L 1内清除作用随浓度的增加而增强;对自由基的清除能力大小：.OH〉H2O2〉O2.。结论在一定浓度范围内,款冬花多糖具有一定的抗氧化活性。     

Stilbenoids isolated from the roots of Rheum lhasaense under the guidance of the acetylcholinesterase inhibition activity

Four unknown stilbenoids, including one dimer, namely 4′-methoxy-scirpusin A (5) and three monomeric stilbene glycosides, namely piceatannol-3′-O-[2′′-(3,5-dihydroxy-4-methoxybenzoyl)]-β-d-glucopyranoside (13), piceatannol-3′-O-(2′′-galloyl)-β-d-glucopyranoside (14) and piceatannol-3′-O-(6″-p-coumaroyl)-β-d-glucopyranoside (16) together with 15 described compounds, were isolated from the ethyl acetate fraction of the ethanol extract of roots of Rheum lhasaense based on the guidance of the inhibitory effect on acetylcholinesterase. The structures of the unknown compounds were established by combined spectroscopic analysis and comparing their spectral data with compounds with similar structures. Some selected components were also investigated for their inhibitory abilities on acetylcholinesterase (AChE), indicating that compound 13 may be responsible for higher inhibitory activity of the ethyl acetate fraction on AChE.

     

Simultaneous quantitative analysis of 11 flavonoid derivatives with a single marker in persimmon leaf extraction and evaluation of their myocardium protection activity

An improved, reliable and comprehensive method for assessing the quality of the ethyl acetate extract from persimmon leaves (EAPL) and its commercial preparation, Naoxinqing (Brain and Heart Clear capsules), has been developed and validated. Based on HPLC–DAD-ESI-Q-TOF–MS analysis, myricetin-3-O-β-d-galactoside (1), myricetin-3-O-glucoside (2), quercetin-3-O-β-d-galactoside (3), quercetin-3-O-β-d-glucoside (4), quercetin-3-O-(2″-O-galloyl-β-d-galactoside) (5), quercetin-3-O-(2″-O-galloyl-β-d-glucoside) (6), kaempferol-3-O-β-d-galactoside (7), kaempferol-3-O-β-d-glucoside (8), kaempferol-3-O-(2″-O-galloyl-β-d-galactoside) (9), kaempferol-3-O-(2″-O-galloyl-β-d-glucoside) (10), quercetin (11) and kaempferol (12) were identified from 15 batch samples. A HPLC fingerprint analytical method was established. All compounds, with the exception of compound 2, were simultaneously quantified by the single standard to determine multi-components (SSDMC) method, using kaempferol-3-O-β-d-glucoside as the internal standard. The rate of analysis was found to be faster with the SSDMC method than with current acid hydrolysis method (Pharmacopoeia of the People's Republic of China 2015 edition) and the results were more intuitive and reliable. Three-dimensional principal component analysis revealed that there were similar characteristics in persimmon leaf from same district. Analysis of the myocardial cell protection activity of 11 monomeric compounds showed that compounds 12, 11 and 10 were the main active ingredients that produce pharmacologic functions in EAPL. Among these compounds, the bioactive constituent of myricetin-3-O-β-d-galactoside was determined for the first time in Diospyros khaki. Thus, we have established an effective assessment method that can be applied to the comprehensive quality evaluation of EAPL extract and Naoxinqing capsule.

     

Synthesis and bioassay of LHRH-antagonists with N-Ac-d-O-phenyltyrosine and N-Ac-d-3-(2-dibenzofuranyl)alanine in position 1

N-Ac-d -O-phenyltyrosine was synthesized via the corresponding azlactone. Resolution of the dl methyl esters was achieved by Subtilisin Carlsberg. Treatment with palladium(II) acetate in trifluoroacetic acid converted N-Ac-d -O-phenyltyrosine into N-Ac-d -3-(2-dibenzofuranyl)alanine. These two amino acids were incorporated instead of N-Ac-d -2-Nal into position 1 of the LHRH-antagonist (N-Ac-d -2-Nal¹, d -pClPhe², d -3-Pal³, c-PzACAla⁵, d -PiCLyS⁶, ILys⁸,d -Ala¹⁰)-LHRH. The more rigid N-Ac-d -3-(2-dibenzofuranyl)alanine was structurally more effective than N-Ac-d -O-phenyltyrosine; the AOAs for the corresponding analogs were 82 and 38%, respectively, at 0.5 μg. Replacement of c-PzACAla in position 5 by O-phenyltyrosine significantly decreased potency.