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1.
Jean Guillon Anita Cohen Nassima Meriem Gueddouda Rabindra Nath Das Stéphane Moreau Luisa Ronga 《Journal of enzyme inhibition and medicinal chemistry》2017,32(1):547-563
Novel series of bis- and tris-pyrrolo[1,2-a]quinoxaline derivatives 1 were synthesized and tested for in vitro activity upon the intraerythrocytic stage of W2 and 3D7 Plasmodium falciparum strains. Biological results showed good antimalarial activity with IC50 in the μM range. In attempting to investigate the large broad-spectrum antiprotozoal activities of these new derivatives, their properties toward Leishmania donovani were also investigated and revealed their selective antiplasmodial profile. In parallel, the in vitro cytotoxicity of these molecules was assessed on the human HepG2 cell line. Structure–activity relationships of these new synthetic compounds are discussed here. The bis-pyrrolo[1,2-a]quinoxalines 1n and 1p were identified as the most potent antimalarial candidates with selectivity index (SI) of 40.6 on W2 strain, and 39.25 on 3D7 strain, respectively. As the telomeres of the parasite could constitute an attractive target, we investigated the possibility of targeting Plasmodium telomeres by stabilizing the Plasmodium telomeric G-quadruplexes through a FRET melting assay by our new compounds. 相似文献
2.
Sahil Kumar Rajesh K. Singh Babita Patial Sachin Goyal 《Journal of enzyme inhibition and medicinal chemistry》2016,31(2):173-186
Malaria is a major public health problem all over the world, particularly in tropical and subtropical countries due to the development of resistance and most deadly infection is caused by Plasmodium falciparum. There is a direct need for the discovery of new drugs with unique structures and mechanism of action to treat sensitive and drug-resistant strains of various plasmodia for radical cure of this disease. Traditional compounds such as quinine and related derivatives represent a major source for the development of new drugs. This review presents recent modifications of 4-aminoquinoline and 8-aminoquinolone rings as leads to novel active molecules which are under clinical trials. The review also encompasses the other heterocyclic compounds emerged as potential antimalarial agents with promising results such as acridinediones and acridinone analogues, pyridines and quinolones as antimalarials. Miscellaneous heterocyclics such as tetroxane derivatives, indole derivatives, imidazolopiperazine derivatives, biscationic choline-based compounds and polymer-linked combined antimalarial drugs are also discussed. At last brief introduction to heterocyclics in natural products is also reviewed. Most of them have been under clinical trials and found to be promising in the treatment of drug-resistant strains of Plasmodium and others can be explored for the same purpose. 相似文献
3.
Antifouling Potential of Some Marine Organisms from India Against Species of Bacillus and Pseudomonas 总被引:2,自引:0,他引:2
Crude methanolic extracts of 37 marine organisms (16 species of flora, 21 species of fauna) were screened for antibacterial
properties against 5 strains of bacteria isolated from marine environments. Of these, 10 plant and 9 animal extracts exhibited
antibacterial activity against at least one bacterial strain. The extracts of 6 species were active against all the strains:
i.e., Stoechospermum marginatum (brown algae), Cymodocea rotundata (seagrass), Petrosia sp. and Psammaplysilla purpurea (sponges), Sinularia compressa (soft coral), and Cassiopeia sp. (jellyfish). Among the plants, Padina tetrastromatica (brown algae) extract exhibited significant activity (9–11-mm inhibition zone at 500 μg per 6-mm disc) against Bacillus pumilus and Pseudomonas vesicularis, while the extracts of Petrosia, Psammaplysilla, and Cassiopeia were strongly active (11–13-mm inhibition zone at 500 μg per 6-mm disc) against B. circulans and P. putida. It was further confirmed that the attachment of bacterial strains on glass slides was inhibited remarkably with increasing
concentrations of bioextracts of Petrosia sp. and Psammaplysilla purpurea. The present findings could form the basis for exploring the antibacterial potential of bioactive molecules from some of
the marine organisms that exhibited moderate to strong antibacterial properties. 相似文献
4.
Eukaryotic initiation factor 5A (eIF5A) has recently been identified as a biomarker of prognostic significance and therapeutic
potential for the treatment in hepatocellular carcinoma. This prompted us to establish a rapid and robust assay to determine
deoxyhypusine and hypusine formed with the purified enzymes deoxyhypusine synthase (DHS) and deoxyhypusine hydroxylase (DOHH)
from Plasmodium to develop a rapid screening assay for antimalarial drugs. The peptide hydrolysate obtained from hypusinylated eIF5A was
analyzed by ultra performance liquid chromatography (UPLC) with retention times for deoxyhypusine of 7.44 min and for hypusine
of 7.30 min, respectively. The limit of detection for both compounds was 0.144 ng/μl. Determination of the specific activity
of Plasmodium DOHH resulted in a twofold higher specific activity than its human counterpart. Following the iron-complexing strategy of
the ferrous iron which is present in the active site of Plasmodium DOHH, a series of iron chelating compounds was tested. 2,2′-Dipyridyl and mimosine abolished DOHH activity completely while
4-oxo-piperidine-carboxylates i.e. the nitrophenylether JK8-2 and EHW 437, the oxime ether of the piperidine aldehyde, showed
no inhibition although they were highly active in in vitro cultures of Plasmodium and in vivo in a rodent mouse model. The method allows a high-throughput screening (HPTS) of antimalarial drugs and the evaluation
of eIF5A as a biomarker. 相似文献
5.
Pharmacophore modeling studies were undertaken for a series of compounds belonging several groups of phosphoinositide 3-kinase
(PI3K) p110α inhibitors: 4-morpholino-2-phenylquinazolines derivatives, pyrido[3′,2′:4,5]furo-[3,2-d]pyrimidine derivatives,
imidazo[1,2-a]pyridine derivatives, sulfonylhydrazone substituted imidazo[1,2-a]pyridines, and LY294002. A five-point pharmacophore
with three hydrogen bond acceptors (A), one hydrophobic group (H), and one aromatic ring (R) as pharmacophore features was
developed. The pharmacophore hypothesis yielded a statistically significant 3D-QSAR model, with a correlation coefficient
of R
2 = 0.95 for training set compounds. The model generated showed excellent predictive power, with a correlation coefficient
of Q
2 = 0.88 and r
pret2 = 0.95 for a test set of 14 compounds. Furthermore, the structure–activity relationships of PI3K p110α inhibitors were elucidated
and the activity differences between them discussed. Docking studies were also carried out wherein active and inactive compounds
were docked into the active site of the PI3K p110α crystal structure to analyze PI3K p110α–inhibitor interactions. The results
provide insights that will aid optimization of these classes of PI3K p110α inhibitors for better activity, and may prove helpful
for further lead optimization and virtual screening. 相似文献
6.
Deniz Tasdemir 《Phytochemistry Reviews》2006,5(1):99-108
Malaria, one of the most problematic infectious diseases worldwide, is on the rise. The absence of an effective vaccine and the spread of drug-resistant strains of Plasmodium clearly indicate the necessity for the development of new chemotherapeutic agents and the identification of novel targets. The recent discovery of a relict, non-photosynthetic plastid-like organelle, the so-called apicoplast, in Plasmodium has opened up new avenues in malaria research. It also initiated the Plasmodium falciparum genome sequencing project, which revealed a number of biochemical pathways previously unknown to Plasmodium, i.e. cytosolic shikimate pathway, apicoplastic type II fatty acid, non-mevalonate isoprene and haem biosyntheses. Since these vital biosynthetic processes are absent in humans or fundamentally different from those found in humans, they represent excellent targets for pharmaceutical interventions. We are interested in the type II fatty acid synthase (FAS II) system of malaria parasite and focus on the FabI enzyme, the only known enoyl-ACP reductase in Plasmodium involved in the final reduction step of the fatty acid chain elongation cycle. Here we describe the general aspects of fatty acid biosynthesis, its essentiality to the malaria parasite and our continuing efforts to discover in Turkish medicinal plants natural antimalarial agents, which specifically target the plasmodial FabI enzyme.Phytochemical Society of Europe (PSE)-Pierre Fabre Prize 2004 Lecture 相似文献
7.
Markus Hartmann Anne Robert Victor Duarte Bernhard K. Keppler B. Meunier 《Journal of biological inorganic chemistry》1997,2(4):427-432
Three new water-soluble ruthenium porphyrin complexes have been prepared and characterized, one with a cationic ligand, Ru(TMPyP),
and two others with anionic ligands, Ru(p–COOH-PP) and Ru(TPPS). These different complexes and their manganese and iron analogues were tested in vivo as potential
antitumor agents with mice bearing P388 leukemia cells, but these complexes have no significant antitumor activity. The nuclease
activity of Ru(TMPyP) and Ru(p–COOH-PP) was evaluated on supercoiled plasmid DNA after activation by a reducing agent (ascorbate) in the presence of air
or by potassium monopersulfate. No significant activity was evidenced for these ruthenium complexes, in contrast with the
already known nuclease activity of the manganese and iron derivatives of TMPyP.
Received: 15 November 1996 / Accepted: 7 April 1997 相似文献
8.
I. Tzovenis E. Fountoulaki N. Dolapsakis I. Kotzamanis I. Nengas I. Bitis Y. Cladas A. Economou-Amilli 《Journal of applied phycology》2009,21(4):457-469
Mediterranean mariculture uses imported strains of marine phytoplankton, raising questions of ecological risk and ability
to adapt to local conditions for mass culture outdoors. In this context, we report here on the mass-culture potential and
chemical composition of six strains of Prasinophyceae (five strains of Tetraselmis sp. and one Pyramimonas sp.) isolated from a Greek coastal lagoon. Proximate composition had a pattern of 10–20% ash, 35–65% protein, 6–10% lipids,
and 25–45% other organics including carbohydrates. The amino acid profiles were typical for the marine representatives of
the class. All strains had a high PUFA content with dominant the ω3 fraction in four of them. The fatty acid profiles indicated
a Tetraselmis strain with high EPA (14%) and a Pyramimonas strain with high DHA (6%). These strains might be a good alternative for the common commercial strains used in Mediterranean
aquaculture. 相似文献
9.
Many fungi harbor double-stranded (ds) RNA molecules, which can have phenotypic effects such as hypovirulence, altered colony
morphology, and pigmentation. In some species of Fusarium, dsRNA molecules are found in every strain examined. We examined 100 F. proliferatum strains collected primarily from maize and sorghum in the United States, but found only four that carried dsRNAs. Each strain
harbored a distinct set of dsRNAs, which ranged in size from approximately 0.7–3.1 kb. A single dsRNA band was observed from
one strain, but multiple bands were observed from the other three. The strains with multiple dsRNAs transmitted these dsRNAs
as sets at a high frequency (≥ 97 %) to vegetatively produced microconidia, but the single dsRNA of the fourth strain was
only rarely (≤ 3 %) transmitted in this manner. None of these dsRNAs could be transmitted through sexual crosses in which
the dsRNA-containing strain served as the male parent. Transmission through the female parent could not be tested as the field
strains and dsRNA-free derivatives of these strains were female sterile. The dsRNAs from the strains with multiple dsRNAs
were present in and protected against ribonuclease A digestion in crude mitochondrial preparations. The high transmission
rate to single-conidiospore cultures, the lack of transmission through the male parent of sexual crosses, and the protection
against ribonuclease A digestion are all consistent with a mitochondrial localization of the dsRNAs from the strains carrying
multiple dsRNAs. dsRNAs often function as viruses in fungi, and the three F. proliferatum strains reported here join strains of Ophiostoma novo-ulmi, Rhizoctonia solani, and Cryphonectria parasitica as the only fungi known to carry dsRNAs associated with the mitochondria.
Contribution number 02-495-J from the Kansas Agricultural Experiment Station (Manhattan). 相似文献
10.
【目的】研究深圳大鹏半岛海域石磺海牛中可培养的共附生细菌的数量和种类,并对分离获得菌株的代谢产物进行活性筛选。【方法】通过R2A平板培养、分离纯化和16SrRNA测序,分析鉴定石磺海牛中5个部位可培养细菌;使用分离菌株的菌液及发酵液上清,测定对群体感应信号分子降解的活性和抗生物膜活性。【结果】从石磺海牛中共分离到215株细菌,归属于87个种,54个属,有16株菌疑似为新菌。分离获得的菌株分布于变形菌门(Proteobacteria,126株),拟杆菌门(Bacteroidetes,44株),厚壁菌门(Firmicutes,34株),放线菌门(Actinobacteria,10株)和浮霉菌门(Planctomycetes,1株)。石磺海牛卵中的细菌数量和种类最为多样。从分离的菌株中筛选出28株菌能够降解群体感应信号分子,8株菌具有抗生物膜活性。【结论】首次报道了海洋无脊椎动物石磺海牛中具有丰富多样的可培养细菌,包含潜在的新微生物和天然产物资源,为今后研究石磺海牛共附生微生物提供了研究基础和参考。 相似文献
11.
E. V. Lavrenteva A. P. Shagzhina O. B. Babasanova Y. E. Dunaevsky Z. B. Namsaraev D. D. Barkhutova 《Applied Biochemistry and Microbiology》2009,45(5):484-488
Two strains of alkaliphilic thermophile bacteria of the genus Anoxybacillus from hydrothermal vents of Lake Baikal were detected and characterized. It was demonstrated that proteinases secreted by
these bacteria had wide substrate specificity, hydrolyzed proteins and n-nitroanilide substrates, and showed maximal activity at pyroglutamyl-alanine-alanine-leucine n-nitroanilide hydrolysis. We determined maximal activity of the proteinases at alkaline pH values (10.0–10.5), the enzymes
were thermostable and were characterized by a wide thermal optimum (55–70°C). The results of inhibitor analysis and substrate
specifity examination of extracellular enzymes demonstrated their belonging to the subtilisin-like serine proteinases. 相似文献
12.
This report surveys the commercial in vitro plant production in Germany from 1985–2004. From twelve commercial tissue culture laboratories starting in 1984, the number increased to 27–30 companies in Germany at the present time. Eight out of them produced more than one million plants per year, and altogether these eight companies account for 92% of total production. Smaller laboratories cloning pathogen-free stock plants for traditional vegetative propagation or breeding purposes are often associated with plant breeding companies or nurseries. Between 1985 and 1992, the total production increased from 5 to nearly 20 million plants per year. Followed by five years of stagnation, in the last seven years (1998–2004) a drastic rise in total production to more than 48 million plants in 2004 was recorded. This steep increase was entirely due to the increasing in vitro production of Phalaenopsis, which now occupies the leading position in flowering pot plants in the Netherlands (Anonymous 2003, Vakblad voor de Bloemisterij 21a: 136). In 2004, German in vitro laboratories produced more than 31 million plants of this orchid. Other important plant genera are Fragaria (3.9 million), Rhododendron (1.0 million), and Gentiana (1.9 million). Plant groups of increasing importance are aquarium plants and garden perennials. 相似文献
13.
The Roseobacter clade, belonging to the family Rhodobacteraceae of the class Alphaproteobacteria, is one of the major bacterial groups in marine environments. A remarkable wealth of diverse large plasmids has been detected
in members of this lineage. Here, we analysed the genome structure and extrachromosomal DNA content of four strains of the
roseobacter species Marinovum
algicola by pulsed-field gel electrophoresis. They were originally isolated from toxic dinoflagellates and possess multireplicon genomes
with sizes between 5.20 and 5.35 Mb. In addition to the single circular chromosomes (3.60–3.74 Mb), whose organisation seem
to be conserved, 9 to 12 extrachromosomal replicons have been detected for each strain. This number is unprecedented for roseobacters
and proposes a sophisticated regulation of replication and partitioning to ensure stable maintenance. The plasmid lengths
range from 7 to 477 kb and our analyses document a circular conformation for all but one of them, which might represent a
linear plasmid-like prophage. In striking contrast to other roseobacters, up to one-third of the genomic information (1.75 Mb)
is plasmid borne in Marinovum
algicola. The plasmid patterns of some strains are conspicuously different, indicating that recombination and conjugative gene transfer
are dominant mechanisms for microevolution within the Roseobacter clade. 相似文献
14.
Ning Sun Ruo-Lan Du Yuan-Yuan Zheng Qi Guo Sen-Yuan Cai Zhi-Hua Liu 《Journal of enzyme inhibition and medicinal chemistry》2018,33(1):879-889
The increasing incidence of multidrug resistant bacterial infection renders an urgent need for the development of new antibiotics. To develop small molecules disturbing FtsZ activity has been recognized as promising approach to search for antibacterial of high potency systematically. Herein, a series of novel quinolinium derivatives were synthesized and their antibacterial activities were investigated. The compounds show strong antibacterial activities against different bacteria strains including MRSA, VRE and NDM-1 Escherichia coli. Among these derivatives, a compound bearing a 4-fluorophenyl group (A2) exhibited a superior antibacterial activity and its MICs to the drug-resistant strains are found lower than those of methicillin and vancomycin. The biological results suggest that these quinolinium derivatives can disrupt the GTPase activity and dynamic assembly of FtsZ, and thus inhibit bacterial cell division and then cause bacterial cell death. These compounds deserve further evaluation for the development of new antibacterial agents targeting FtsZ. 相似文献
15.
Many microbes associated with marine organisms have antimicrobial activity. We report the isolation of bacteria associated
with Amphipholis gracillima that have broad-spectrum antibacterial activity against a number of common bacterial strains. Fifty-eight isolates of bacilli
obtained from A. gracillima arm homogenates, from excised wound tissue, or from swabs of arm stumps exhibited 20–100% inhibition of one or more of 16
test bacteria at 35% salinity. Forty-one of the isolates were capable of 20–100% inhibition of one or more of 19 subject bacteria
at 10% salinity at 37°C. Three isolates, BE37, BE52, and BE53, exhibited the greatest range of antibacterial activity at both
10% and 35% salinity. Our results suggest that some of the bacteria associated with A. gracillima may provide the animal with chemical defenses against adverse bacterial infection. The water-soluble inhibitory chemicals
produced by the bacteria could potentially function as antimicrobial compounds against human pathogenic bacteria.
Received: 30 July 2001 / Accepted: 15 October 2001 相似文献
16.
Antioxidants are important defenders of the human body against nocive free radicals, which are the causative agents of most
life-threatening diseases. The immense biomedicinal utility of antioxidants necessitates the development and design of new
synthetic antioxidant molecules. The present report deals with the modeling of a series of chromone derivatives, which was
done to provide detailed insight into the main structural fragments that impart antioxidant activity to these molecules. Four
different quantitative structure–property relationship (QSAR) techniques, namely 3D pharmacophore mapping, comparative molecular
similarity indices analysis (CoMSIA 3D-QSAR), hologram QSAR (HQSAR), and group-based QSAR (G-QSAR) techniques, were employed
to obtain statistically significant models with encouraging external predictive potentials. Moreover, the visual contribution
maps obtained for the different models signify the importance of different structural features in specific regions of the
chromone nucleus. Additionally, the G-QSAR models determine the composite influence of pairs of substituent fragments on the
overall antioxidant activity profiles of the molecules. Multiple models with different strategies for assessing structure–activity
relationships were applied to reach a unified conclusion regarding the antioxidant mechanism and to provide consensus predictions,
which are more reliable than values derived from a single model. The structural information obtained from the various QSAR
models developed in the present work can thus be effectively utilized to design and predict the activities of new molecules
belonging to the class of chromone derivatives. 相似文献
17.
Mithun Rudrapal Dipak Chetia Vineeta Singh 《Journal of enzyme inhibition and medicinal chemistry》2017,32(1):1159-1173
Among three series of 1,2,4-trioxane derivatives, five compounds showed good in vitro antimalarial activity, three compounds of which exhibited better activity against P. falciparum resistant (RKL9) strain than the sensitive (3D7) one. Two best compounds were one from aryl series and the other from heteroaryl series with IC50 values of 1.24 µM and 1.24 µM and 1.06 µM and 1.17 µM, against sensitive and resistant strains, respectively. Further, trioxane derivatives exhibited good binding affinity for the P. falciparum cysteine protease falcipain 2 receptor (PDB id: 3BPF) with well defined drug-like and pharmacokinetic properties based on Lipinski’s rule of five with additional physicochemical and ADMET parameters. In view of having antimalarial potential, 1,2,4-trioxane derivative(s) reported herein may be useful as novel antimalarial lead(s) in the discovery and development of future antimalarial drug candidates as P. falciparum falcipain 2 inhibitors against resistant malaria. 相似文献
18.
Tara C. Smith Pamela J. Weathers Ronald D. Cheetham 《In vitro cellular & developmental biology. Plant》1997,33(1):75-79
Summary Artemisinin (AN), a potent antimalarial drug that has been used for centuries as a folk remedy in China, is an effective treatment
against quinine-resistant strains of Plasmodium. It can be produced through the in vitro culture of genetically transformed (hairy) roots. The effect of gibberellic acid (GA3) on the growth and secondary metabolite production of hairy roots of Artemisia annua was investigated. Six different concentrations of GA3 were tested in shaker flasks to determine the optimum concentration. GA3 levels of 0.01–0.001 mg/l (28.9–2.89 μM) provided the most significant increase in biomass, and 0.01 mg/l (28.9 μM) produced the highest amount of AN. Investigation of growth kinetics showed that the use of GA3 at 0.01 mg/l (28.9 μM) increased the growth rate of hairy roots of A. annua by 24.9%. Thus, the cultures treated with GA3 reached stationary phase faster than control cultures. 相似文献
19.
Lone Gram Jette Melchiorsen Jesper Bartholin Bruhn 《Marine biotechnology (New York, N.Y.)》2010,12(4):439-451
The purpose of the present study was to isolate marine culturable bacteria with antibacterial activity and hence a potential
biotechnological use. Seawater samples (244) and 309 swab samples from biotic or abiotic surfaces were collected on a global
Danish marine research expedition (Galathea 3). Total cell counts at the seawater surface were 5 × 105 to 106 cells/ml, of which 0.1–0.2% were culturable on dilute marine agar (20°C). Three percent of the colonies cultured from seawater
inhibited Vibrio anguillarum, whereas a significantly higher proportion (13%) of colonies from inert or biotic surfaces was inhibitory. It was not possible
to relate a specific kind of eukaryotic surface or a specific geographic location to a general high occurrence of antagonistic
bacteria. Five hundred and nineteen strains representing all samples and geographic locations were identified on the basis
of partial 16S rRNA gene sequence homology and belonged to three major groups: Vibrionaceae (309 strains), Pseudoalteromonas spp. (128 strains), and the Roseobacter clade (29 strains). Of the latter, 25 strains were identified as Ruegeria mobilis or pelagia. When re-testing against V. anguillarum, only 409 (79%) retained some level of inhibitory activity. Many strains, especially Pseudoalteromonas spp. and Ruegeria spp., also inhibited Staphylococcus aureus. The most pronounced antibacterial strains were pigmented Pseudoalteromonas strains and Ruegeria spp. The inhibitory, pigmented Pseudoalteromonas were predominantly isolated in warmer waters from swabs of live or inert surfaces. Ruegeria strains were isolated from all ocean areas except for Arctic and Antarctic waters and inhibitory activity caused by production
of tropodithietic acid. 相似文献