Tag: M.W=100-150

Ghosh, Tonmoy; Mondal, Aniruddha; Vamsi Bharadwaj, S. V.; Mishra, Sandhya published the artcile< A naturally fluorescent protein C-phycoerythrin and graphene oxide bio-composite as a selective fluorescence ""turn off/on"" probe for DNA quantification and characterization>, Recommanded Product: 7H-Purin-2-amine, the main research area is C phycoerythrin graphene oxide DNA quantification fluorescence characterization; C-phycoerythrin; DNA sensing; Fluorescence quenching; Graphene oxide; Protein – graphene oxide interaction.

Highly specific graphene-DNA interactions have been at the forefront of graphene-based sensor design for various analytes, including DNA itself. However, in addition to its detection, DNA also needs to be characterized according to its size and concentration in a sample, which is an addnl. anal. step. Designing a highly sensitive and selective DNA sensing and characterization platform is, thus, of great interest. The present study demonstrates that a bio-derived, naturally fluorescent protein C-phycoerythrin (CPE) – graphene oxide (GO) bio-composite can be used to detect dsDNA in nanomolar quantities efficiently via fluorescent “”turn off/on”” mechanism. Interaction with GO temporarily quenches CPE fluorescence in a dose-dependent manner. Anal. characterization indicates an indirect charge transfer with a corresponding loss of crystalline GO structure. The fluorescence is regained with the addition of DNA, while other biomols. do not pose any hinderance in the detection process. The extent of regain is DNA length dependent, and the corresponding calibration curve successfully quantifies the size of an unknown DNA. The incubation time for detection is ∼3-5 min. The bio-composite platform also works successfully in a complex biomol. matrix and cell lysate. However, the presence of serum albumin poses a hinderance in the serum sample. Particle size anal. proves that CPE displacement from GO surface by the incoming DNA is the reason for the “”turn on”” response, and that the sensing process is exclusive to dsDNA. This new platform could be an exciting and rapid DNA sensing and characterization tool.

International Journal of Biological Macromolecules published new progress about Albumins Role: BSU (Biological Study, Unclassified), BIOL (Biological Study). 452-06-2 belongs to class imidazoles-derivatives, and the molecular formula is C5H5N5, Recommanded Product: 7H-Purin-2-amine.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

He, Yanhua; Yu, Youwei; Wen, Xiaoye; Shi, Yan; Wu, Jianhu; Guan, Zhengping; Cui, Meilin; Xiao, Chunling published the artcile< A quencher-free 2-aminopurine modified hairpin aptasensor for ultrasensitive detection of Ochratoxin A>, Recommanded Product: 7H-Purin-2-amine, the main research area is aminopurine hairpin aptasensor Ochratoxin A fluorescence quenching; 2-Aminopurine; Aptasensor; Exonuclease I; Ochratoxin A; Quencher-free.

A sensitive, efficient and quencher-free fluorescence aptasensor to detect Ochratoxin A (OTA) based on aptamer, 2-aminopurine (2AP) labeled Oligonucleotide sequence, as well as exonuclease I (Exo I) activity was developed. In which the aptamer specific to OTA was modified into a hairpin structure, and 8 bases at the 3′ ends are exposed (H); also, 2AP is embedded in the oligonucleotide complementary to the 8 bases (2AP-probe). The detection principle based on 2AP-probe could be bonded to its complementary sequence and quenches the fluorescence of 2AP; The aptamer has a stronger affinity for the target than its complementary sequence; Exo I can dissociate single-stranded DNA and has little effect on double-stranded DNA as well as folded DNA. In the absence of OTA, the fluorescence of 2AP is quenched due to the complementary pairing of H and 2AP-probe; in the presence of OTA, H selective binding target is detached from 2AP-probe, and the fluorescence of 2AP is slightly restored. Moreover, when the Exo I is added to the detection system, 2AP-probe is dissociated by the Exo I to release the free 2AP, and the fluorescence of the system is further enhanced thereby realizing the detection of OTA. The detection limit of the aptasensor was low as 0.03 nM with a linear range of 0.5-100 nM. Moreover, the aptasensor has good selectivity and practicability and also has good potential in realizing the detection of toxic and harmful substances in food complex matrixes.

Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy published new progress about Aptasensors. 452-06-2 belongs to class imidazoles-derivatives, and the molecular formula is C5H5N5, Recommanded Product: 7H-Purin-2-amine.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Prasanthkumar, Kavanal P.; Rayaroth, Manoj P.; Alvarez-Idaboy, Juan R. published the artcile< Insights into the Mechanism of Hydroxyl Radical Mediated Oxidations of 2-Aminopurine: A Computational and Sonochemical Product Analysis Study>, Category: imidazoles-derivatives, the main research area is aminopurine hydroxyl radical mediated oxidation sonochem.

Mechanistic details of hydroxyl radical (•OH) mediated oxidations of 2-aminopurine (2AP) in the aqueous phase have been established in this study via a combination of DFT calculations (at the M05-2X/6-311+G(d,p) level with SMD solvation) and sonochem. end product analyses by the LC-Q-TOF-MS/MS method. Rate constants and branching ratios for single electron transfer (SET), two H-abstractions (HA), and seven radical adduct formation (RAF) reactions of •OH with 2AP were evaluated using transition state theory (TST). The RAF at the C8-position of 2AP is noted as the dominant process, which constitutes almost 46.1% of overall reaction routes. The SET mechanism accounts for the second major pathway (39.6%) followed by RAF at the C6-position (14.3%). Formations of 14 transformation products (TPs, i.e., the nonradical end products) in the sonochem. reactions of •OH with 2AP have been identified by means of the LC-Q-TOF-MS/MS technique. Among the 14 TPs (designated as TP1 to TP14), the lowest and highest mass to charge ratio (m/z) were resp. observed at 129 and 269 in ESI-MS pos. ionization mode. The identities of all TPs have been proposed on the basis of elemental composition of [M + H]+ ions and their resp. MS-MS fragmentation pattern. Four TPs (including guanine) are considered as obtained directly from primary transients by radical elimination, radical-radical combination/disproportionation reactions. The remaining 10 TPs are postulated as a result of successive self- and/or cross-reactions of primary transients/four first generation TPs with reagents such as •OH, O2, and solvent H2O mols.

Journal of Physical Chemistry B published new progress about Collision-induced dissociation. 452-06-2 belongs to class imidazoles-derivatives, and the molecular formula is C5H5N5, Category: imidazoles-derivatives.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Zheng, Yangyang; Hong, Kunqiang; Wang, Baowei; Liu, Dingyu; Chen, Tao; Wang, Zhiwen published the artcile< Genetic Diversity for Accelerating Microbial Adaptive Laboratory Evolution>, Application In Synthesis of 452-06-2, the main research area is review accelerating microbial adaptive laboratory genetic diversity; adaptive laboratory evolution; genetic diversity; genome editing; mutant library.

A review. Adaptive laboratory evolution (ALE) is a widely used and highly effective tool for improving microbial phenotypes and investigating the evolutionary roots of biol. phenomena. Serving as the raw materials of evolution, mutations have been extensively utilized to increase the chances of engineering mols. or microbes with tailor-made functions. The generation of genetic diversity is therefore a core technol. for accelerating ALE, and a high-quality mutant library is crucial to its success. Because of its importance, technologies for generating genetic diversity have undergone rapid development in recent years. Here, we review the existing techniques for the construction of mutant libraries, briefly introduce their mechanisms and applications, discuss ongoing and emerging efforts to apply engineering technologies in the construction of mutant libraries, and suggest future perspectives for library construction.

ACS Synthetic Biology published new progress about Alkylating agents. 452-06-2 belongs to class imidazoles-derivatives, and the molecular formula is C5H5N5, Application In Synthesis of 452-06-2.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Chen, Mingjian; Ma, Changbei; Zhao, Han; Yan, Ying published the artcile< Exonuclease III-assisted fluorometric aptasensor for the carcinoembryonic antigen using graphene oxide and 2-aminopurine>, Recommanded Product: 7H-Purin-2-amine, the main research area is carcinoembryonic antigen exonuclease aptasensor graphene oxide aminopurine; Aptamer; Carcinoembryonic antigen; Enzyme; Fluorescence amplification; Fluorescently labelled probe.

A reliable fluorometric assay is described for the determination carcinoembryonic antigen (CEA) using exonuclease III (Exo III) and a 2-aminopurine binding aptamer. In the absence of CEA, dsDNA is degraded by Exo III, and free 2-AP (which has a blue fluorescence with excitation/emission maxima of 310/365 nm) is released. Strong fluorescence is generated after addition of graphene oxide (GO) to the solution However, the 2-AP modified DNA (T2) cannot be degraded in the presence of CEA by Exo III due to the interaction between CEA and aptamer T1. Hence, only weak fluorescence can be detected after addition of GO. In this system, CEA can be quantified in the 0.05 – 2 ng·mL-1 concentration range with a detection limit of 30 pg·mL-1 (at S/N = 3). The method was successfully applied to analyze serum samples for CEA.

Microchimica Acta published new progress about Aptasensors. 452-06-2 belongs to class imidazoles-derivatives, and the molecular formula is C5H5N5, Recommanded Product: 7H-Purin-2-amine.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Szabla, Rafał; Zdrowowicz, Magdalena; Spisz, Paulina; Green, Nicholas J; Stadlbauer, Petr; Kruse, Holger; Šponer, Jiří; Rak, Janusz published the artcile< 2,6-diaminopurine promotes repair of DNA lesions under prebiotic conditions.>, Electric Literature of 452-06-2, the main research area is .

High-yielding and selective prebiotic syntheses of RNA and DNA nucleotides involve UV irradiation to promote the key reaction steps and eradicate biologically irrelevant isomers. While these syntheses were likely enabled by UV-rich prebiotic environment, UV-induced formation of photodamages in polymeric nucleic acids, such as cyclobutane pyrimidine dimers (CPDs), remains the key unresolved issue for the origins of RNA and DNA on Earth. Here, we demonstrate that substitution of adenine with 2,6-diaminopurine enables repair of CPDs with yields reaching 92%. This substantial self-repairing activity originates from excellent electron donating properties of 2,6-diaminopurine in nucleic acid strands. We also show that the deoxyribonucleosides of 2,6-diaminopurine and adenine can be formed under the same prebiotic conditions. Considering that 2,6-diaminopurine was previously shown to increase the rate of nonenzymatic RNA replication, this nucleobase could have played critical roles in the formation of functional and photostable RNA/DNA oligomers in UV-rich prebiotic environments.

Nature communications published new progress about 452-06-2. 452-06-2 belongs to class imidazoles-derivatives, and the molecular formula is C5H5N5, Electric Literature of 452-06-2.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Czernecki, Dariusz; Legrand, Pierre; Tekpinar, Mustafa; Rosario, Sandrine; Kaminski, Pierre-Alexandre; Delarue, Marc published the artcile< How cyanophage S-2L rejects adenine and incorporates 2-aminoadenine to saturate hydrogen bonding in its DNA>, Recommanded Product: 7H-Purin-2-amine, the main research area is .

Abstract: Bacteriophages have long been known to use modified bases in their DNA to prevent cleavage by the host′s restriction endonucleases. Among them, cyanophage S-2L is unique because its genome has all its adenines (A) systematically replaced by 2-aminoadenines (Z). Here, we identify a member of the PrimPol family as the sole possible polymerase of S-2L and we find it can incorporate both A and Z in front of a T. Its crystal structure at 1.5 Å resolution confirms that there is no structural element in the active site that could lead to the rejection of A in front of T. To resolve this contradiction, we show that a nearby gene is a triphosphohydolase specific of dATP (DatZ), that leaves intact all other dNTPs, including dZTP. This explains the absence of A in S-2L genome. Crystal structures of DatZ with various ligands, including one at sub-angstrom resolution, allow to describe its mechanism as a typical two-metal-ion mechanism and to set the stage for its engineering.

Nature Communications published new progress about 452-06-2. 452-06-2 belongs to class imidazoles-derivatives, and the molecular formula is C5H5N5, Recommanded Product: 7H-Purin-2-amine.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Nejad, Maryam Imani; Price, Nathan E.; Haldar, Tuhin; Lewis, Calvin; Wang, Yinsheng; Gates, Kent S. published the artcile< Interstrand DNA cross-links derived from reaction of a 2-aminopurine residue with an abasic site>, Electric Literature of 452-06-2, the main research area is interstrand DNA crosslink derived reaction aminopurine abasic.

Efficient methods for the site-specific installation of structurally-defined interstrand crosslinks in duplex DNA may be useful in a wide variety of fields. The work described here developed a high-yield synthesis of chem. stable interstrand crosslinks resulting from a reductive amination reaction between an abasic site and the noncanonical nucleobase 2-aminopurine in duplex DNA. Results from footprinting, LC-MS, and stability studies support the formation of an N2-alkylamine attachment between the 2-aminopurine residue and the Ap site. The reaction performs best when the 2-aminopurine residue on the opposing strand is offset 1 nt to the 5′-side of the abasic site. The crosslink confers substantial resistance to thermal denaturation (melting). The crosslinking reaction is fast (complete in 4 h), employs only com. available reagents, and can be used to generate crosslinked duplexes in sufficient quantities for biophys., structural, and DNA repair studies.

ACS Chemical Biology published new progress about DNA damage. 452-06-2 belongs to class imidazoles-derivatives, and the molecular formula is C5H5N5, Electric Literature of 452-06-2.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Malina, Jaroslav; Kostrhunova, Hana; Scott, Peter; Brabec, Viktor published the artcile< FeII Metallohelices Stabilize DNA G-Quadruplexes and Downregulate the Expression of G-Quadruplex-Regulated Oncogenes>, Recommanded Product: 7H-Purin-2-amine, the main research area is Fe Metallohelices DNA G quadruplexes oncogenes; DNA; G-quadruplexes; metalo-supramolecular helicates; multitargeted agens; oncogenes.

DNA G-quadruplexes (G4s) have been identified within the promoter regions of many proto-oncogenes. Thus, G4s represent attractive targets for cancer therapy, and the design and development of new drugs as G4 binders is a very active field of medicinal chem. Here, mol. biophysics and biol. methods were employed to investigate the interaction of chiral metallohelices with a series of four DNA G4s (hTelo, c-myc, c-kit1, c-kit2) that are formed by the human telomeric sequence (hTelo) and in the promoter regions of c-MYC and c-KIT proto-oncogenes. We show that the investigated water-compatible, optically pure metallohelices, which are made by self-assembly of simple nonpeptidic organic components around FeII ions and exhibit bioactivity emulating the natural systems, bind with high affinity to G4 DNA and much lower affinity to duplex DNA. Notably, both enantiomers of a metallohelix containing a m-xylenyl bridge (5 b) were found to effectively inhibit primer elongation catalyzed by Taq DNA polymerase by stabilizing G4 structures formed in the template strands containing c-myc and c-kit2 G4-forming sequences. Moreover, both enantiomers of 5 b downregulated the expression of c-MYC and c-KIT oncogenes in human embryonic kidney cells at mRNA and protein levels. As metallohelices also bind alternative nucleic acid structures, they hold promise as potential multitargeted drugs.

Chemistry – A European Journal published new progress about Animal gene Role: BSU (Biological Study, Unclassified), PRP (Properties), BIOL (Biological Study) (c-kit1). 452-06-2 belongs to class imidazoles-derivatives, and the molecular formula is C5H5N5, Recommanded Product: 7H-Purin-2-amine.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Wannberg, Johan; Gising, Johan; Lindman, Jens; Salander, Jessica; Gutierrez-de-Teran, Hugo; Ablahad, Hanin; Hamid, Selin; Groenbladh, Alfhild; Spizzo, Iresha; Gaspari, Tracey A.; Widdop, Robert E.; Hallberg, Anders; Backlund, Maria; Lesniak, Anna; Hallberg, Mathias; Larhed, Mats published the artcile< N-(Methyloxycarbonyl)thiophene sulfonamides as high affinity AT2 receptor ligands>, Product Details of C7H12N2, the main research area is AT2 receptor ligand thiophene sulfonamide; AT(2)R ligands; Angiotensin II type 2 receptor; Carboxylic acid bioisosteres; Liver microsomes; Sulfonyl carbamates.

A series of meta-substituted acetophenone derivatives, encompassing N-(alkyloxycarbonyl)thiophene sulfonamide fragments have been synthesized. Several selective AT2 receptor ligands were identified, among those a tert-butylimidazole derivative (20) with a Ki of 9.3 nM, that demonstrates a high stability in human liver microsomes (t1/2 = 62 min) and in human hepatocytes (t1/2 = 194 min). This methyloxycarbonylthiophene sulfonamide is a 20-fold more potent binder to the AT2 receptor and is considerably more stable in human liver microsomes, than a previously reported and broadly studied structurally related AT2R prototype antagonist 3 (C38). Ligand 20 acts as an AT2R agonist and caused an AT2R mediated concentration-dependent vasorelaxation of pre-contracted mouse aorta. Furthermore, in contrast to imidazole derivative C38, the tert-butylimidazole derivative 20 is a poor inhibitor of CYP3A4, CYP2D6 and CYP2C9. It is demonstrated herein that smaller alkyloxycarbonyl groups make the ligands in this series of AT2R selective compounds less prone to degradation and that a high AT2 receptor affinity can be retained after truncation of the alkyloxycarbonyl group. Binding modes of the most potent AT2R ligands were explored by docking calculations combined with mol. dynamics simulations.

Bioorganic & Medicinal Chemistry published new progress about Angiotensin AT1 receptors Role: BSU (Biological Study, Unclassified), BIOL (Biological Study). 36947-69-0 belongs to class imidazoles-derivatives, and the molecular formula is C7H12N2, Product Details of C7H12N2.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem