Structural characteristics and thermodynamic properties of dG 3 (T 2 AG ) , d(C TA C /d(C were intensively investigated. It was indicated that metal ions greatly affected the conformation stability G‐quadruplex. A competition a structure transition among G‐quadruplex, I‐motif, duplex confirmed to be dependent on both cation species pH values. The structural competitive mechanism is discussed for first time. This study shows an intriguing potential in modulating DNA structures vivo, which...

A clear difference in the enthalpy changes derived from spectroscopic and calorimetric measurements has recently been shown. The exact interpretation of this deviation varied study to study, but it was generally attributed non‐two‐state transition heat capacity change. Although temperature‐dependent thermodynamics duplex formation often implied, systemic extensive studies have lacking universally assigning appropriate thermodynamic parameter sets. In present 24 DNA/DNA 41 RNA/DNA...

Polyprodrug nanoparticles have been employed recently for safer and more effective cancer treatment. However, it remains a challenge to elucidate how when the polyprodrug are dissociated activated release active drugs in cells. Herein, visible light-activatable Pt(IV) prodrug an aggregation-induced emission luminogen (AIEgen) were copolymerized embedded main chain of PtAIECP, chemotherapeutic doxorubicin (DOX) was subsequently encapsulated self-assembled by PtAIECP (PtAIECP@DOX NP)....

Cytochrome P450 enzymes play a pivotal role in biosynthetic and metabolic transformations. Especially, cytochrome reductase (CPR) acts as the key electron donor for oxygen activation by monoxygenases, but transfer mechanism within CPR is largely elusive. Here, extensive molecular dynamics (MD) quantum mechanics/molecular mechanics (QM/MM) calculations were performed to elucidate CPR's mechanism. We found that from FADH– FMN occurs through proton-coupled (PCET) Glu142 transfers proton via...

The effects of cytosine protonation and various cations on the properties parallel pyrimidine motif DNA triplexes were intensively investigated characterized by several different techniques, such as circular dichroism (CD) conformation, ultraviolet (UV) melting, differential scanning calorimetry (DSC) thermal denaturation, surface plasmon resonance (SPR) real-time dynamics. comparative CD spectra triplex corresponding homoduplexes showed that negative peak at ∼218 nm would be eigenpeak...

DNA is a promising material for the construction of biosensor or bioindicator because its structure sensitive to binding cofactors. In current studies, we found that combination two oligonucleotides, 5'-TCTTTCTCTTCT-3' and 5'-AGAAAGAGAAGA-3', exhibit novel structural transition from Watson−Crick antiparallel duplex parallel Hoogsteen as pH changes 7.0 5.0. By labeling this fluorescence resonance energy transfer, were able develop indicator can detect between Moreover, using DNA-based hairpin...

Chemotherapy is the most common therapeutic strategy for treatment of unresectable hepatocellular carcinoma. However, efficacy limited by low delivery efficiency chemotherapeutics and severe toxicity towards healthy tissues. To address these challenges, active-targeting mesoporous silica nanoparticles conjugating a platinum(iv) prodrug were developed as therapy liver cancer first time. Taking advantage liver-targeting lactobionic acid (LA), smart nano-carriers not only enhanced circulation...

We report the macrocyclic ring size–electronic structure–electrophilic reactivity correlation of mononuclear nonheme iron(III)-peroxo complexes bearing N-tetramethylated cyclam analogues (n-TMC), [FeIII(O2)(12-TMC)]+ (1), [FeIII(O2)(13-TMC)]+ (2), and [FeIII(O2)(14-TMC)]+ (3), as a model study Rieske oxygenases. The Fe(III)-peroxo show same δ pseudo-σ bonds between iron peroxo ligand. However, strength these interactions varies depending on size n-TMC ligands; overall Fe–O bond Fe–O2...

Abstract Mononuclear nonheme iron enzymes catalyze a large variety of oxidative transformations responsible for various biosynthesis and metabolism processes. Unlike their P450 counterparts, non‐heme generally possess flexible variable coordination architecture, which can endow rich reactivity enzymes. This Concept highlights that the dynamics be key player in controlling activity selectivity In ergothioneine synthase EgtB, switch sulfoxide radical species enables efficient selective C−S...

Abstract Upon addition of protecting osmolyte to an aqueous solution intrinsically unstructured protein, spectral observables are often seen change in a sigmoid fashion as function increasing concentration. Commonly, such data analyzed using the linear extrapolation model (LEM), method that defines scale from 0%–100% folded species at each concentration by means extending pre‐ and post‐folding baselines into transition region. Defining folding correctly for is important part analysis,...

Abstract High‐speed counter‐current chromatography (HSCCC) was successfully applied for the preparative separation and purification of alkaloids from Corydalis bungeana Turcz. (Kudiding in Chinese) first time. After measurement partition coefficient seven target nine two‐phase solvent systems composed CHCl 3 –MeOH–(0.1 M; 0.2 0.3 M) HCl (4:1.5:2; 4:2:2; 4:3:2, v/v), –MeOH–0.2 M (4:2:2, v/v) –MeOH–0.3 (4:3:2, were finally selected HSCCC using upper phase as stationary stepwise elution two...

The non-heme iron ergothioneine synthase (EgtB) is a sulfoxide that catalyzes oxidative C-S bond formation in the synthesis of ergothioneine, which plays roles against stress cells. Despite extensive experimental and computational studies catalytic mechanisms EgtB, root causes for selective remain elusive. Using quantum mechanics/molecular mechanics (QM/MM) calculations, we show herein coordination switch intermediate involved catalysis EgtB. This from S to O atom driven by S/π electrostatic...

Chelating lability significantly hinders the development of Mn(II)-based magnetic resonance image (MRI) contrast agents. Herein, using 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA) as a chelating unit, we show that multinuclear Mn(II) united-DOTA chelates are up to 69-fold higher inertness than Magnevist, clinical Gd-based agent. The unusual could be ascribed multiplexed uniting chelates, which is illustrated by series controlled studies on model compounds. Besides,...

Photoresponsive drug delivery stands as a pivotal frontier in smart administration, leveraging the non-invasive, stable, and finely tunable nature of light-triggered methodologies. The generative pre-trained transformer (GPT) has been employed to generate molecular structures. In our study, we harnessed GPT-2 on QM7b dataset refine UV-GPT model with adapters, enabling generation molecules responsive UV light excitation. Utilizing Coulomb matrix descriptor, predicted excitation wavelengths...

Abstract Single crystals of the alkali‐metal hypodiphosphates K 4 P 2 O 6 · 8H ( 1 ) and Na could be obtained their crystal structures determined. The compounds crystallize isotypic in orthorhombic space group Pbca (no. 61) with four formula units unit cell. are built up by discrete [P ] 4– an ethane‐like staggered conformation, corresponding cations water molecules. FT‐IR/FIR FT‐Raman spectra crystalline title were recorded a complete assignment for modes is proposed. Raman aqueous...

Transition characteristics and thermodynamic properties of the single-stranded self-transition double-stranded association were investigated analyzed for 9-, 15- 21-bp non-self-complementary DNA sequences. The multiple transition processes further put forth. experimental results confirmed that was generally imperfect would exert an influence on a duplex formation. Combining ultraviolet melting experiments in various molar ratios, extent estimated three DNAs. In our range, decreases with...

Abstract Three new chiral stationary phases ( CSPs ) for high‐performance liquid chromatography were prepared from R ‐(3,3'‐halogen substituted‐1,1'‐binaphthyl)‐20‐crown‐6 (halogen = Cl, Br and I). The experimental results showed that ‐(3,3'‐dibromo‐1,1'‐binaphthyl)‐20‐crown‐6 CSP ‐1 possesses more prominent enantioselectivity than the two other halogen‐substituted crown ether derivatives. All twenty‐one α ‐amino acids have different degrees of separation on...

Abstract Single crystals of Rb 2 H P O 6 · 2H could be obtained from aqueous solutions hypodiphosphoric acid and rubidium carbonate. Its crystal structure was determined by X‐ray diffraction it crystallizes in the monoclinic space group 1 / c with Z = 4. The salt‐like title compound consists [H ] 2– units staggered ‐skeleton conformation, + cations, molecules, held together intermolecular hydrogen bonds type ··· O. vibrational spectra (IR/FIR Raman) salt were recorded an assignment modes is...

Abstract The transition metal dihydrogen hypodiphosphate hydrates K 2 [Co(H P O 6 ) (H O) ] · H ( 1 ), [Ni(H [Cu(H 3 and [Zn(H 4 were synthesized characterized by single crystal structure determination. compounds – crystallize isotypic in the monoclinic space group C 2/ m (no. 12) with two formula units unit cell. is built up [H 2– an eclipsed conformation, corresponding metal, potassium cations, water molecules. conformation of has not been previously observed none known...

In order to find a high-speed countercurrent chromatography solvent system that can be used as general prefractionation step for anthraquinone, the crude extracts of five traditional Chinese medicines, Radix rubiae, Rhizoma polygoni cuspidati, Semen cassiae, et rhizoma rhei, and Aloe were separated with two-phase composed CHCl3:CH3OH:H2O = 4:x:2 in which x was between 3 4 different samples. The fractionated components identified on TLC. This gave good separation most anthraquinones.