In vitro antibacterial activity of some Iranian medicinal plant extracts against Helicobacter pylori

Helicobacter pylori infection causes lifelong chronic gastritis, which can lead to peptic ulcer, mucosa-associated lymphoid tissue (MALT) lymphoma and gastric cancer. The growing problem of antibiotic resistance by the organism demands the search for novel candidates from plant-based sources. In the present study, we evaluated the in vitro anti-H. pylori activity of some selected medicinal plants on clinical isolates of H. pylori. Gastric biopsy samples were obtained from patients presenting with gastroduodenal complications. Helicobacter pylori was isolated from the specimens following standard microbiology procedures. The disc-diffusion method was used to determine the susceptibility of three H. pylori isolates to methanol extracts of 23 Iranian plants. All tests were performed in triplicate. Among them, the extracts of Punica granatum and Juglans regia had remarkable anti-H. pylori activity with mean of inhibition zone diameter of 39 and 16?mm at 100?μg?disc?1, respectively. In view of the results obtained with P. granatum (pomegranate), the peel extracts of nine cultivars of pomegranate (Shirin-e-Pust Sefid, Agha Mohammad Ali-e-Shirin, Sefid-e-Shomal, Sefid-e-Torsh, Shirin-e-Malase, Tabestani-e-Torsh, Shirin-e-Saveh Malase, Alak-e-Shirin, Pust Siyah) were further assayed against the clinical isolates of H. pylori. The results revealed that all Iranian pomegranate cultivars, except for Alak-e-Shirin, showed significant in vitro anti-H. pylori activity against the clinical isolates of H. pylori (mean of inhibition zone diameter ranging from 16 to 40 mm at 50 μg disc?1).     

噻唑偶氮衍生物与铋的显色反应的研究

光度法是测定物料中微量铋的灵敏方法。经典的分光光度法灵敏度很低而不能满足需要。近期发展的铋与DBDTC、磺基萤光酮、邻苯二酚紫、甲基百里酚蓝、ДБФФ等三元配合物体系,灵敏度均属中等,其中只有ДБФФ在CPC存在下是高灵敏的(ε=1.1×10~5)。因此研究铋的新的高灵敏显色剂是有意义的。Саввин等曾合成以4,5-二甲基噻唑为母体的显色剂,但与金属离子反应的灵敏度不高。用我们首次合成的2-(4,5-二甲基噻唑-2-偶氮)-5-二乙氨基苯酚(DMTAE)为试剂(简称H_nR),可明显地提高试剂与金属离子铋(Ⅲ)、镓(Ⅲ)、镉(Ⅱ)等显色反应的灵敏度。在30％乙醇水溶液中或在表面活性剂的胶束增溶作用下,铋的摩尔吸光度达10~5数量级。本文详细     

Tracking bismuth antiulcer drug uptake in single Helicobacter pylori cells

Bismuth-based drugs have long been used for the treatment of Helicobacter pylori infection. In this work, the metal content in H. pylori was monitored at the single-cell level by time-resolved inductively coupled plasma mass spectrometry, and ～2.9 × 10(7) Mg atoms/cell was determined for the wild-type. Bacteria treated with a Bi antiulcer drug deposited nearly 1.0 × 10(6) Bi atoms/cell, whereas the uptake process took ～3 h to reach the half-maximum. Interference of ferric ions on bismuth uptake was demonstrated, suggesting that the metallodrug can utilize certain iron-transport pathways in the pathogen. The approach provides a general strategy for monitoring metals in single cells, facilitating exploration of metal-relevant bioprocesses.     

One-pot synthesis of a pentasaccharide with antibiotic activity against Helicobacter pylori

A pentasaccharide that contains the alpha-1,4-GlcNAc mucin core two-branched O-glycan has been synthesized by a one-pot, two-step glycosylation strategy; this particular carbohydrate motif may provide protection against H. pylonri induced pathologies since the synthetic pentasaccharide inhibits cholesterol alpha-glucosyltransferase (IC50 of 0.47 mM).     

Complexes of gold(iii) and titanium(iii) with 8-hydroxyquinoline

The preparation of an 8-hydroxyquinoline complex of trivalent gold by the action of oxine upon gold chloride and “monopyridine gold chloride” is described. The absorption spectrum of the complex, which approximated to the composition AuCl₂C₉H₆ON was plotted in the U.V. and visible regions of the spectrum.A partial separation between tri- and tetravalent titanium was obtained using paper chromatography. Absorption curves were obtained for oxine complexes of Ti(III) and Ti(IV) in the visible region of the spectrum.     

Synthesis and Characterisation of Bismuth(III) Aminoarenesulfonate Complexes and Their Powerful Bactericidal Activity against Helicobacter pylori

The synthesis and characterisation of nine new tris‐substituted bismuth(III) aminoarenesulfonates of the general formula [Bi(O₃S‐R^N)₃] (R^N=o‐aminophenyl 1 , m‐aminophenyl 2 , 6‐amino‐3‐methoxyphenyl 3 , p‐aminophenyl 4 , 2‐pyridyl 5 , o‐aminonaphthyl 6 , 5‐aminonaphthyl 7 , 4‐amino‐3‐hydroxynaphthyl 8 and 5‐isoquinolinyl 9 ) is described. Two synthetic strategies, using Ag₂O and [Bi(OtBu)₃], were explored and compared. The possibility to access heteroleptic bismuth(III) complexes with the new silver(I) metathesis reaction is demonstrated with the synthesis of the heteroleptic bismuth(III) aminoarenesulfonate complexes [PhBi(O₃S‐P2)₂(dmso)] 10 , [Ph₂Bi(O₃S‐P2)]_∞ 11 and [PhBi(O₃S‐P2)₂]_∞ 12 , of which the solid state structures 10 and 12 are presented (2P‐SO₃^?=2‐pyridinesulfonate). These complexes offer remarkable in‐vitro activity against three standard laboratory strains of Helicobacter pylori (H. pylori) as demonstrated by their exceptionally low minimum inhibitory concentration (MIC) values of 0.049 μg mL^?1 for the strains 251 and B128, which places most MIC values in the nano‐molar region. These results demonstrate the importance of the amino functionality in addition to the sulfonate group on the bactericidal properties against H. pylori.     

Synthesis of a natural oligosaccharide antibiotic active against Helicobacter pylori

An oligosaccharide active against Helicobacter pylori was synthesized in a highly efficient manner for the first time. The anti-H. pylori oligosaccharide structure is a core-2 branched-type oligosaccharide with a characteristic alpha-N-acetylglucosamine at the nonreducing end. The oligosaccharide was synthesized from the nonreducing end to the reducing end, with an N-benzyl-2,3-oxazolidinone-carrying glycosyl donor used to introduce an alpha-N-acetylglucosamine at the nonreducing end. Complete chemoselective activation of a bromo sugar in the presence of a thioglycoside acceptor was achieved, and the use of 2,6-dimethylphenyl thioglycoside prevented the aglycon transfer observed when the corresponding phenyl thioglycoside is used as an acceptor.     

Chemical analysis of the semipurified extract of Paullinia cupana and evaluation of in vitro inhibitory effects against Helicobacter pylori

Abstract

Paullinia cupana Kunth, commonly known as guarana, is a native Brazilian plant species from the Amazon area that presents various biological effects, including antimicrobial action. The aim of this study was to chemically analyse the semipurified aqueous extract (AqF) of the plant and to evaluate the activity of crude (CE), ethyl-acetate (EAF), and AqF extracts against Helicobacter pylori. The chemical profile of AqF was determined based on solid analysis ¹³C-NMR, direct infusion mass spectrometry (ESI-MS), and MALDI-TOF. The ¹³C-NMR spectrum showed characteristics of flavan-3-ol and oligomeric proanthocyanidins. ESI-MS revealed the presence of procyanidin, caffeic acid and its derivatives. MALDI-TOF analysis detected procyanidins of up to 6 units and profisetinidins of up to 5 units. Whereas CE and EAF showed inhibitory activity against H. pylori, CE, EAF, and AqF presented not high inhibitory activity against urease. The results demonstrate the potential of P. cupana to control and prevent H. pylori infection.     

Unusual nitro-coordination of europium(iii) and terbium(iii) with pyridinyl ligands

A new ligand family based on picoline, bipyridine and terpyridine containing a nitro moiety has been synthesized and its coordination and sensitization ability for lanthanide ions has been studied. Three new complexes were characterized by X-ray single crystal diffraction and all three show uncommon coordination of the nitro moiety to the lanthanide ion. , a terpyridine-nitro derivative with Tb(NO(3))(3), crystallizes in the orthorhombic space group Pbca with a = 15.125(3), b = 13.776(3), c = 18.716(4) ?, and V = 3899.8(13) ?(3) and is isostructural with its Eu(iii) analog () with cell parameters a = 15.1341(4), b = 13.7070(4), c = 18.8277(5) ?. , a tripodal amine with a nitro-derivatized pyridine with Eu(CF(3)SO(3))(3), crystallizes in the triclinic space group P1[combining macron] with a = 11.067(2), b = 11.633(2), c = 12.772(3) ?, α = 110.94(3), β = 97.49(3), γ = 91.42(3)° and V = 1518.1(5) ?(3). Finally, ligand , a bipyridine-nitro derivative, crystallizes in the orthorhombic space group P2(1)/n with a = 3.7128(3), b = 11.7806(8), c = 19.9856(14) ?, β = 92.925(2)° and V = 873.01(11) ?(3). All four ligands show sensitization of Eu(iii) and Tb(iii) luminescence.     

Sorption of bismuth(iii) and its chloride complexes with 2-aminopyrimidine cation on hydroxyapatite of various textures

Russian Chemical Bulletin - Specific features of the interaction between bismuth(iii) and hydroxyapatite (HAP) of various morphologies during its sorption and co-crystallization binding were...     

Mono- and binuclear chloride complexes of bismuth(iii) with 2-aminopyrimidine cations depending on specific synthetic route

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Synthesis, structure, and activity evaluation of two silver(I) complexes as Helicobacter pylori urease inhibitors

Two silver(I) compounds, [Ag(R,R-hxn)](C₇H₄BrO₂) · 2H₂O (I) (Chxn = 1,2-diaminocyclohexane) and [Ag(C₅H₆N₂)₂]₂(C₈H₄O₄) · 10H₂O (II), were synthesized and complex I was structurally characterized by X-ray crystallography. Compound I contains a catena-(trans-1,2-diaminocyclohexane) silver polycation ([Ag(Chxn)]_∞) in a roughly linear fashion, while II possesses a linear-type silver monocation. Compounds I and II were evaluated for their inhibitory activities against Helicobacter pylori urease in vitro. Both were found to have strong inhibitory activities against H. pylori urease comparable to that of acetohydroxamic acid.     

Spermine increases bactericidal activity of silver-nanoparticles against clinical methicillin-resistant Staphylococcus aureus

Spermine can effectively reinforce the antibacterial activity of AgNPs.     

Synthesis of ruthenium(iii) and rhodium(iii) tris-acetylacetonates and palladium(ii) bis-ketoiminate using microwave heating

Preparation of ruthenium(iii) and rhodium(iii) tris-acetylacetonates and palladium(ii) bisketoiminate (Pd(i-acac)₂) under microwave irradiation using different synthetic conditions, both in the solid-phase and in solution, was studied with precise control of parameters. In the solid-phase systems, the preparation of the target product was hindered. The efficiency of the microwave heating increased when liquid phases of the reagent mixtures were used. For Pd(i-acac)₂, the highest yield was achieved under elevated temperature of the process, with the reaction time decreasing to several minutes. A laboratory procedure for the microwave synthesis of ruthenium(iii) and rhodium(iii) tris-acetylacetonates and palladium(ii) bis-ketoiminate in aqueous solutions was developed, which allowed us to obtain them in 85, 55, and 80% yields, respectively. These yields are higher than those reported in the literature, with the process becoming considerably less time consuming and laborious.     

The solvent extraction of cobalt(iii) from a trisoxalatocobaltate(iii) solution into chloroform containing acetylacetone

The rate of the extraction of cobalt(III) from aqueous solutions containing trisoxalatocobaltate(lll) into chloroform containing acetylacetone has been investigated. The effects of pH, acetylacetone concentration, oxalate concentration, complex concentration, temperature, and possible change in oxidation state are reported.     

Reaction of erbium(iii) carbonate with thenoyltrifluoroacetone: The molecular structure of hydrate hydroxonium tetrakis(thenoyltrifluoroacetonato)erbate(iii)

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Catalytic activity of rhodium-indigo sulfonates in hydrogen-water isotope exchange

Rhodium indigo sulfonate complexes are effective catalysts of isotope exchange between hydrogen and water. A study has been made of the transformation of initial complexes into catalytically active forms. Kinetic regularities of isotope exchange and an equation for the reaction rate have been obtained.

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Spectrophotometric determination of chromium(iii) with complexans

Selective spectrophotometric determinations of milligrain amounts of chromium(III) with complexans are described, based on the fact that the chromium(IIl) complexes are formed rapidly at boiling temperatures, but very slowly at room temperature, while the formation of some interfering complexes takes place instantaneously. Determinations with EDTA are more sensitive, but the combined presence of cobalt and other metals still interferes; there is no interference with the less sensitive NTA. The combined presence of a l00-fold amount of copper, nickel, cobalt and iron generally has no effect on the results. The use of DCTA, DTPA and HEDTA is discussed.     

Screening and characterization of medicinal plants extracts with bactericidal activity against Streptococcus mutans

Abstract

The aim of the present study was to perform a screening of extracts obtained from 15 medicinal plants using water (at 25 and 90?°C) or ethanol (at 25?°C), to bactericidal activity against cariogenic S. mutans ATCC 25175, as well as to carry out the preliminary phytochemical characterization of the extracts and HPLC/MS assay for selected extracts. The extractions were carried out for 5?h at 400?rpm. Only five from 45 tested extracts were selected based on their antibacterial activity. The IC₅₀ varied from of 28?ppm for Quercus ilex up to 250?ppm for Jatropha dioica. Different polyphenolic and quinic acids, flavonoids, anthocyanin or tyrosol were identified by HPLC/MS in selected extracts from Rosa gallica L., Jatropha dioica Sessé, Mimosa tenuiflora (Willd.) Poir, Quercus ilex L., and Solanum nigrum. The obtained results confirm that selected extracts are good candidates to be used for cariogenic bacteria control.