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Open accessJournal ArticleDOI: 10.1016/J.SAA.2020.119185

Study of alkaloid berberine and its interaction with the human telomeric i-motif DNA structure

05 Mar 2021-Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy (Elsevier)-Vol. 248, pp 119185-119185
Abstract: The alkaloid berberine presents many biological activities related to its potential to bind DNA structures, such as duplex or G-quadruplex. Recently, it has been proposed that berberine may interact with i-motif structures formed from the folding of cytosine-rich sequences. In the present work, the interaction of this alkaloid with the i-motif formed by the human telomere cytosine-rich sequence, as well as with several positive and negative controls, has been studied. Molecular fluorescence and circular dichroism spectroscopies, as well as nuclear magnetic resonance spectrometry and competitive dialysis, have been used with this purpose. The results shown here reveal that the interaction of berberine with this i-motif is weak, mostly electrostatics in nature and takes place with bases not involved in C·C+ base pairs. Moreover, this ligand is not selective for i-motif structures, as binds equally to both, folded structure, and unfolded strand, without producing any stabilization of the i-motif. As a conclusion, the development of analytical methods based on the interaction of fluorescent ligands, such as berberine, with i-motif structures should consider the thermodynamic aspects related with the interaction, as well as the selectivity of the proposed ligands with different DNA structures, including unfolded strands.

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Topics: G-quadruplex (53%), Base pair (52%), Berberine (51%)

6 results found

Journal ArticleDOI: 10.1080/13543776.2021.1974001
Yuan Kong1, Lin Li1, Linguo Zhao1, Pan Yu2  +1 moreInstitutions (2)
Abstract: Introduction Berberine (BBR), as one of the outstanding representatives of isoquinoline alkaloids, has been used as an antibacterial drug for a long time in China since ancient times. Currently, a large number of studies have been reported that berberine has a wide spectrum of pharmacological activities, such as anti-tumor, anti-inflammatory, hypoglycemic, hypolipidemic, anti-obesity, and the like. Areas covered This review systematically discussed important patents on berberine and berberine derivatives in terms of pharmacological activity between 2016 and 2020. These patents were mainly searched through the European Patent Office database and Web of Science. These berberine patents (~41) cover a wide range of applications, mainly including antitumor, anti-inflammatory, antibacterial, anti-metabolic disorder, and other newly reported pharmacological activities. Expert opinion Berberine is an important lead compound with great potential for optimization in drug development. However, there is a lack of research related to the biomolecular targets of BBR, which directly restricts the development of berberine in the pharmaceutical field. The problems involved with poor bioavailability and cytotoxicity are also worth considering in the development of berberine-based drugs. Accordingly, the increasing number of patents involving biomolecular targets in BBR's patent applications will be published as its related pharmacological mechanisms are further deciphered.

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Topics: Berberine (53%)

2 Citations

Journal ArticleDOI: 10.1016/J.PDPDT.2021.102547
Ping Zhao1, Zi-Wei Tang1, Hui-Chao Lin1, David Djuanda2  +8 moreInstitutions (3)
Abstract: Background Nucleic acids used as drug delivery systems (DDS) have gained attention because of their biosafety and effortless synthesis. G-quadruplex (G4) structured aptamer such as AS1411 was frequently employed to deliver photosensitizers or chemotherapeutic agents while other aptamers were seldomly reported in this field. Methods Herein, a chemical anticancer drug daunomycin (DNM), and a photosensitizer 5, 10, 15, 20-tetra (phenyl-4-N-methyl-4-pyridyl) porphyrin (TMPyP) were physically assembled with a novel DNA structure composed of an aptamer of vascular endothelial growth factor (VEGF) and a cytosine (C)-rich DNA fragment (gc-34). Spectral and molecular mimicking methods were employed to research the drug loading/releasing process. The in vitro cytotoxicity was studied by MTT, ROS, cell cycle, and cell apoptotic assays and the in vivo anticancer efficiency was evaluated by the inhibitive effect on the cancerous growth of MCF-7 tumor-bearing nude mice. Results The G4-structured VEGF aptamer delivered TMPyP successfully for the first time. The designed DDS displayed sensitive VEGF/pH controlled drug release. The co-delivery of DNM and TMPyP exhibited high ROS production, significant cell cycle arresting and evident cell apoptosis, and displayed superior cytotoxicity against tumor cells compared with individual agents in vitro. In vivo studies showed that the dual-drug loaded system can greatly inhibit tumor growth with chemotherapeutic/photodynamic synergistic effects. Conclusion The co-delivery of DNM and TMPyP with aptamer/C-rich DNA successfully integrates the functions of VEGF/pH stimuli-responsive drug release and chemotherapeutic/phototherapeutic modalities into one single system, and may have great potential in cancer treatment.

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Topics: Aptamer (54%), Drug delivery (53%), Combination chemotherapy (53%) ... read more

Open accessJournal ArticleDOI: 10.1016/J.BPC.2021.106715
Abstract: There is an increasing interest in the study of guanine or cytosine-rich sequences that may fold into G-quadruplex (G4) or i-motif (iM) structures showing a short hairpin (or stem-loop) stabilized by Watson-Crick base pairs. These hybrid spatial arrangements may be target of ligands that have been shown to interact strongly with B-DNA. In this work, the interaction of the palmatine alkaloid with several sequences forming different G4s, iMs, and hybrid structures has been studied by means of spectroscopic and separation techniques, as well as multivariate data analysis methods. At the experimental conditions used in this work, the results have shown that this ligand strongly stabilizes parallel G4 structures, whereas a weaker interaction was observed with the antiparallel G4 adopted by the thrombin-binding aptamer or iMs. The presence of hairpins within the loops scarcely affects the affinity of this ligand for the hybrid G4/duplex or iM/duplex structures. Fluorescence measurements have provided evidence of a certain interaction with iMs at pH 5.1, despite the absence of thermal stabilization effects.

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Journal ArticleDOI: 10.1177/08853282211049620
Bo Fu, Hui-Chao Lin1, Ying-Chun Liu, Jie-Rou Lin  +5 moreInstitutions (1)
Abstract: Chemotherapeutic agents and photosensitizers often suffer from poor tumor selectivity, high side toxicity, or low water solubility. To address these problems, various drug delivery systems (DDS) ha...

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Topics: Drug delivery (54%), Nanocarriers (52%)


73 results found

Open accessJournal ArticleDOI: 10.1093/NAR/GKG595
Michael Zuker1Institutions (1)
Abstract: The abbreviated name,‘mfold web server’,describes a number of closely related software applications available on the World Wide Web (WWW) for the prediction of the secondary structure of single stranded nucleic acids. The objective of this web server is to provide easy access to RNA and DNA folding and hybridization software to the scientific community at large. By making use of universally available web GUIs (Graphical User Interfaces),the server circumvents the problem of portability of this software. Detailed output,in the form of structure plots with or without reliability information,single strand frequency plots and ‘energy dot plots’, are available for the folding of single sequences. A variety of ‘bulk’ servers give less information,but in a shorter time and for up to hundreds of sequences at once. The portal for the mfold web server is mfold. This URL will be referred to as ‘MFOLDROOT’.

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Topics: Web server (61%), Server (53%), Software portability (51%)

11,636 Citations

Journal ArticleDOI: 10.1039/C0CS00062K
Pall Thordarson1Institutions (1)
Abstract: The most common approach for quantifying interactions in supramolecular chemistry is a titration of the guest to solution of the host, noting the changes in some physical property through NMR, UV-Vis, fluorescence or other techniques. Despite the apparent simplicity of this approach, there are several issues that need to be carefully addressed to ensure that the final results are reliable. This includes the use of non-linear rather than linear regression methods, careful choice of stoichiometric binding model, the choice of method (e.g., NMRvs.UV-Vis) and concentration of host, the application of advanced data analysis methods such as global analysis and finally the estimation of uncertainties and confidence intervals for the results obtained. This tutorial review will give a systematic overview of all these issues—highlighting some of the key messages herein with simulated data analysis examples.

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1,224 Citations

Open accessJournal ArticleDOI: 10.1093/NAR/GKP026
Abstract: Here we review studies that provided important information about conformational properties of DNA using circular dichroic (CD) spectroscopy. The conformational properties include the B-family of structures, A-form, Z-form, guanine quadruplexes, cytosine quadruplexes, triplexes and other less characterized structures. CD spectroscopy is extremely sensitive and relatively inexpensive. This fast and simple method can be used at low- as well as high-DNA concentrations and with short- as well as long-DNA molecules. The samples can easily be titrated with various agents to cause conformational isomerizations of DNA. The course of detected CD spectral changes makes possible to distinguish between gradual changes within a single DNA conformation and cooperative isomerizations between discrete structural states. It enables measuring kinetics of the appearance of particular conformers and determination of their thermodynamic parameters. In careful hands, CD spectroscopy is a valuable tool for mapping conformational properties of particular DNA molecules. Due to its numerous advantages, CD spectroscopy significantly participated in all basic conformational findings on DNA.

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1,194 Citations

Open accessJournal ArticleDOI: 10.1093/NAR/GKM234
Warren A. Kibbe1Institutions (1)
Abstract: We developed OligoCalc as a web-accessible, client-based computational engine for reporting DNA and RNA single-stranded and doublestranded properties, including molecular weight, solution concentration, melting temperature, estimated absorbance coefficients, inter-molecular self-complementarity estimation and intramolecular hairpin loop formation. OligoCalc has a familiar ‘calculator’ look and feel, making it readily understandable and usable. OligoCalc incorporates three common methods for calculating oligonucleotide-melting temperatures, including a nearest-neighbor thermodynamic model for melting temperature. Since it first came online in 1997, there have been more than 900 000 accesses of OligoCalc from nearly 200 000 distinct hosts, excluding search engines. OligoCalc is available at http://basic.north, with links to the full source code, usage patterns and statistics at that link as well.

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1,055 Citations

Open accessBook
01 Jan 2000-
Abstract: Providing a comprehensive account of the structures and physical chemistry properties of nucleic acids, with special emphasis on biological function, this text is for those with only a basic understanding of physical chemistry and molecular biology.

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Topics: Structural biology (56%)

861 Citations

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