Jing Shi

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Name: 石景; Shi, Jing

Organization: University of Science and Technology of China , China

Department: Department of Chemistry

Title: Associate Professor(PhD)

TOPICS

Organic Chemistry

Polymer

UV Absorbents

Chemicals
References

Mechanistic Study of Copper-Catalyzed Decarboxylative C–N Cross-Coupling with Hypervalent Iodine Oxidant

Co-reporter:Yi-Nuo Yang, Ju-Long Jiang, and Jing Shi

Organometallics June 12, 2017 Volume 36(Issue 11) pp:2081-2081

Publication Date(Web):May 19, 2017

DOI:10.1021/acs.organomet.7b00095

Copper-catalyzed directed decarboxylative C–N cross-coupling, which is promoted by a hypervalent iodine oxidant, provides a new strategy for the site-selective formation of aliphatic C–N bonds. Despite the great synthetic potential, the mechanism of this reaction and especially the origin of the radical species still remain controversial. To resolve this problem, herein density functional theory (DFT) calculations have been employed to elucidate the mechanistic details of this reaction. As a result, a comprehensive reaction pathway involving IIII–O bond heterolysis, single electron transfer (SET), hydrogen atom transfer (HAT), decarboxylation, proton transfer, and reductive elimination is reported. Meanwhile, analyzing the necessity of the directing groups in realizing the site selectivity, we found that the chelation of the directing group to the Cu(III) center can remarkably facilitate the proton transfer process.

Dmab/ivDde protected diaminodiacids for solid-phase synthesis of peptide disulfide-bond mimics

Co-reporter:Yang Xu, Tao Wang, Chao-Jian Guan, Yi-Ming Li, Lei Liu, Jing Shi, Donald Bierer

Tetrahedron Letters 2017 Volume 58, Issue 17(Issue 17) pp:

Publication Date(Web):26 April 2017

DOI:10.1016/j.tetlet.2017.03.024

•A new diaminodiacid containing Dmab/ivDde protecting groups has been prepared.•The new diaminodiacid was used to successfully prepare an oxytocin disulfide mimetic.•Dmab/ivDde protecting groups avoid the use of heavy metal reagents during cleavage.The use of pre-prepared diaminodiacids has been established as an effective approach for the chemical synthesis of peptide disulfide bond mimics. A technical problem often encountered in the implementation of the diaminodiacids strategy is the use of heavy metal reagents to remove the side-chain protecting groups. In the present work, we reported the development of diaminodiacid that carry 4-(N-[1-(4,4-dimethyl-2,6-dioxocyclo-hexylidene)-3-methylbutyl]amino)benzyl (Dmab) and 1-(4,4-dimethyl-2,6-dioxocyclohex-1-ylidene)-3-methylbutyl (ivDde) protecting groups. This pair of protecting groups can be readily removed by mild hydrazinolysis during the solid-phase synthesis on resin. We demonstrated the use of Dmab/ivDde protected diaminodiacids in the successful synthesis of a disulfide surrogate of oxytocin.Download high-res image (123KB)Download full-size image

A diubiquitin-based photoaffinity probe for profiling K27-linkage targeting deubiquitinases

Co-reporter:Xiao-Dan Tan;Man Pan;Shuai Gao;Yong Zheng;Yi-Ming Li

Chemical Communications 2017 vol. 53(Issue 73) pp:10208-10211

Publication Date(Web):2017/09/12

DOI:10.1039/C7CC05504H

K27-linkage poly-ubiquitination plays important roles in DNA damage repair and autoimmunity. Identification of K27-linkage targeting deubiquitinases (DUBs) is essential for understanding their regulatory mechanisms. Here we report an aryl-azide-based photoaffinity diubiquitin (diUb) probe for profiling K27-linkage targeting DUBs. This probe shows high selectivity and sensitivity towards K27-linkage DUBs in vitro. It can also be used in cell lysate for identifying and probing K27-linkage targeting DUBs in real proteomes. Our work suggests that the photoaffinity-based strategy may provide a new useful approach for the construction of other isopeptide linkage targeting DUB probes.

Diaminodiacid-based solid-phase synthesis of all-hydrocarbon stapled α-helical peptides

Co-reporter:Feng-Liang Wang, Ye Guo, Si-Jian Li, Qing-Xiang Guo, Jing Shi and Yi-Ming Li

Organic & Biomolecular Chemistry 2015 vol. 13(Issue 22) pp:6286-6290

Publication Date(Web):29 Apr 2015

DOI:10.1039/C5OB00741K

An alternative stapling strategy is described herein using Fmoc-solid phase peptide synthesis (SPPS) that employed pre-prepared diaminodiacid building blocks to introduce all-hydrocarbon staples into peptides by on-resin cyclization. Compared to unstapled native peptides, diaminodiacid-based stapled peptides exhibited an increased α-helicity ratio and stability toward protease. Moreover, the linkage length was found to affect the bioactivity of the peptides and their ability to inhibit the Wnt pathway. Therefore, the new stapling method provides an alternative way to obtain stapled peptides with tunable linkers of diaminodiacids.

Mechanistic study on the regioselectivity of Co-catalyzed hydroacylation of 1,3-dienes

Co-reporter:Yuan-Ye Jiang, Hai-Zhu Yu, Jing Shi

Chinese Chemical Letters 2015 Volume 26(Issue 1) pp:58-62

Publication Date(Web):January 2015

DOI:10.1016/j.cclet.2014.10.021

Density functional theory (DFT) method was used to explore the origin of the regioselectivity of Co-catalyzed hydroacylation of 1,3-dienes. The reaction of 2-methyl-1,3-butadiene and benzaldehyde with 1,3-bis(diphenylphosphino)propane ligand was chosen as the model reaction. The energies of the intermediates and transition states in the stages of oxidative cyclization, β-H elimination and C-H reductive elimination were investigated. Computational results show that β-H elimination is the rate-determining step for the whole catalytic cycle. C1-Selective oxidative cyclization is favored over C4-selective oxidative cyclization. Besides, C4-selective oxidative cyclization is kinetically disfavored than all the steps in C1-hydroacylation mechanisms, consistent with the experimentally obtained C1-selective hydroacylation products. Analyzing the reason for such observation, we suggest that both electronic and steric effects contribute to the C1-selectivity. On the electronic aspect, C1 is more electron rich than C4 due to the methyl group on C2, which makes the electrophilic attack of aldehyde carbon on C1 more favorable. On the steric aspect, the methyl group locates farther from the ligands in the transition state of C1-selective oxidative cyclization than in that of C4-selective oxidative cyclization.The origin of C1-selectivity in Co-catalyzed hydroacylation of 1,3-dienes was investigated by density functional theory studies, and found to be resulted from the electronic and steric effects of the substitutes R′ on 1,3-dienes.

Facile and efficient chemical synthesis of APET×2, an ASIC-targeting toxin, via hydrazide-based native chemical ligation

Co-reporter:Si-Jian Li, Da-Liang Qu, Ye-Hai Wang, Yao He, Min Wen, Qing-Xiang Guo, Jing Shi, Yi-Ming Li

Tetrahedron 2015 Volume 71(Issue 21) pp:3363-3366

Publication Date(Web):27 May 2015

DOI:10.1016/j.tet.2015.03.098

Acid-sensing ion channels (ASICs) targeting peptides APET×2, a minor constituent in the venom of the sea anemone Anthopleura elegantissima, was synthesized via hydrazide-based native chemical ligation with high yields. Synthetic APET×2 exhibited well-defined three-dimensional structure after an optimized folding process. Therefore, we present a simple and cost-efficient strategy for the chemical synthesis of ASIC3 inhibitor APET×2.

Thiol-assisted one-pot synthesis of peptide/protein C-terminal thioacids from peptide/protein hydrazides at neutral conditions

Co-reporter:Chenchen Chen, Yichao Huang, Ling Xu, Yong Zheng, Huajian Xu, Qingxiang Guo, Changlin Tian, Yiming Li and Jing Shi

Organic & Biomolecular Chemistry 2014 vol. 12(Issue 46) pp:9413-9418

Publication Date(Web):01 Oct 2014

DOI:10.1039/C4OB01885K

An efficient thiol-assisted one-pot synthesis of peptide/protein C-terminal thioacids was achieved by using peptide/protein hydrazides precursors at neutral pH and room temperature (about 20 °C). The transformation from hydrazides to thioacids was shown to be efficient for different C-terminal amino acids and was racemization-free. The in situ formed peptide-thioacids were further used for protein chemical synthesis and site-specific labelling successfully.

Accurate predictions of C–SO2R bond dissociation enthalpies using density functional theory methods

Co-reporter:Hai-Zhu Yu, Fang Fu, Liang Zhang, Yao Fu, Zhi-Min Dang and Jing Shi

Physical Chemistry Chemical Physics 2014 vol. 16(Issue 38) pp:20964-20970

Publication Date(Web):09 Jun 2014

DOI:10.1039/C4CP02005G

The dissociation of the C–SO2R bond is frequently involved in organic and bio-organic reactions, and the C–SO2R bond dissociation enthalpies (BDEs) are potentially important for understanding the related mechanisms. The primary goal of the present study is to provide a reliable calculation method to predict the different C–SO2R bond dissociation enthalpies (BDEs). Comparing the accuracies of 13 different density functional theory (DFT) methods (such as B3LYP, TPSS, and M05 etc.), and different basis sets (such as 6-31G(d) and 6-311++G(2df,2p)), we found that M06-2X/6-31G(d) gives the best performance in reproducing the various C–S BDEs (and especially the C–SO2R BDEs). As an example for understanding the mechanisms with the aid of C–SO2R BDEs, some primary mechanistic studies were carried out on the chemoselective coupling (in the presence of a Cu-catalyst) or desulfinative coupling reactions (in the presence of a Pd-catalyst) between sulfinic acid salts and boryl/sulfinic acid salts.

Accurate Prediction of IrH Bond Dissociation Enthalpies by Density Functional Theory Methods

Co-reporter:Yi Zhou;Dingjia Liu;Yao Fu;Haizhu Yu

Chinese Journal of Chemistry 2014 Volume 32( Issue 3) pp:269-275

Publication Date(Web):

DOI:10.1002/cjoc.201400015

Abstract

The iridium hydride complexes have been extensively used in organic reactions, such as oxidation and hydrogenation reactions. In many of these reactions, the dissociation or formation of IrH bond plays an important role in determining the overall reaction rates and yields. In the present study, the accuracy of different theoretical methods for prediction of IrH bond strengths has been examined on the basis of the previously reported IrH BDEs of 17 different complexes. Comparing the performance of different DFT functionals (e.g. B3LYP, TPSS, M06), different basis sets (including the different effective core potentials (ECP) on Ir and I atoms, and the total electron basis sets on the other atoms), and different solvation models (SMD, CPCM, and IEFPCM) in solution phase single point calculations, we found that the gas-phase calculation with TPSS/(LanL2DZ: 6-31G(d)) method is relatively more accurate than the other gas-phase calculation methods, and can well simulate the IrH BDEs in low-polarity solvents (such as chlorobenzene and dichloroethane). Finally, efforts were put in analyzing the structure-activity relationships between the ligand structure (around Ir center) and the IrH BDEs. We wish the present study could benefit future studies on the Ir-H complexes involved organic reactions.

Accurate prediction of rate constants of Diels–Alder reactions and application to design of Diels–Alder ligation

Co-reporter:Shi-Ya Tang, Jing Shi and Qing-Xiang Guo

Organic & Biomolecular Chemistry 2012 vol. 10(Issue 13) pp:2673-2682

Publication Date(Web):26 Jan 2012

DOI:10.1039/C2OB07079K

Bioorthogonal reactions are useful tools to gain insights into the structure, dynamics, and function of biomolecules in the field of chemical biology. Recently, the Diels–Alder reaction has become a promising and attractive procedure for ligation in bioorthogonal chemistry because of its higher rate and selectivity in water. However, a drawback of the previous Diels–Alder ligation is that the widely used maleimide moiety as a typical Michael acceptor can readily undergo Michael addition with nucleophiles in living systems. Thus, it is important to develop a nucleophile-tolerant Diels–Alder system in order to extend the scope of the application of Diels–Alder ligation. To solve this problem, we found that the theoretical protocol M06-2X/6-31+G(d)//B3LYP/6-31G(d) can accurately predict the activation free energies of Diels–Alder reactions with a precision of 1.4 kcal mol−1 by benchmarking the calculations against the 72 available experimental data. Subsequently, the electronic effect and ring-strain effect on the Diels–Alder reaction were studied to guide the design of the new dienophiles. The criteria of the design is that the designed Diels–Alder reaction should have a lower barrier than the Michael addition, while at the same time it should show a similar (or even higher) reactivity as compared to the maleimide-involving Diels–Alder ligation. Among the designed dienophiles, three substituted cyclopropenes (i.e. 1,2-bis(trifluoromethyl)-, 1,2-bis(hydroxylmethyl)- and 1,2-bis(hydroxylmethyl)-3-carboxylcyclopropenes) meet our requirements. These substituted cyclopropene analogs could be synthesized and they are thermodynamically stable. As a result, we propose that 1,2-bis(trifluoromethyl)-, 1,2-bis(hydroxylmethyl)- and 1,2-bis(hydroxylmethyl)-3-carboxylcyclopropenes may be potential candidates for efficient and selective Diels–Alder ligation in living systems.

Hydride Dissociation Energies of Six-Membered Heterocyclic Organic Hydrides Predicted by ONIOM-G4Method

Co-reporter:Jing Shi, Xiong-Yi Huang, Hua-Jing Wang, and Yao Fu

Journal of Chemical Information and Modeling 2012 Volume 52(Issue 1) pp:63-75

Publication Date(Web):December 7, 2011

DOI:10.1021/ci2001567

Hydride dissociation energy is of great importance in understanding the hydride-donating abilities of organic hydrides. Although the hydride dissociation energies of some organic hydrides have been experimentally measured, much less attention has been focused on the investigation of these quantities from the first principles of physics. Herein, we developed an ONIOM-G4 method and carefully benchmarked this new method against 48 experimental hydride dissociation energies of diverse bulky molecules. It was found that with the combined methods of the HF/6-31+G(d,p)//IEFPCM/Bondi1.15 solvation model, the ONIOM-G4 method can predict the hydride dissociation energies with an error bar of only 1.7 kcal/mol. With the newly developed ONIOM-G4 method, we then systematically studied the hydride dissociation energies of six categories of biologically and pharmaceutically important six-membered heterocyclic organic hydrides, namely, the organic hydrides containing 1,4-dihydropyridine, 1,4-dihydropyrazine, 1,4-oxazine, 1,4-thiazine, 4H-pyran, and 4H-thiopyran ring structures. An extensive hydride dissociation energy scale containing over 100 six-memebered heterocyclic organic hydrides has been established, which may find applications in both synthetic organic chemistry and mechanistic studies of various chemical or biological processes involving transferring of the hydride anion.

Mechanistic Origin of Regioselectivity in Nickel-Catalyzed Olefin Hydroheteroarylation through C–H Activation

Co-reporter:Yuan-Ye Jiang ; Zhe Li

Organometallics 2012 Volume 31(Issue 11) pp:4356-4366

Publication Date(Web):May 22, 2012

DOI:10.1021/om300329z

Ni-catalyzed addition of electron-deficient arenes and heteroarenes to olefin substrates through C–H activation provides an important method for the synthesis of diarylalkanes. This reaction usually generates Markovnikov adducts for aryl olefins, whereas anti-Markovnikov adducts are obtained for alkyl-substituted alkenes. To understand the mechanistic origin of this interesting regioselectivity, we conducted density functional theory calculations using the reactions of benzoxazole with styrene and 1-hexene as models. The calculation results are consistent with experimental observations, showing that the reaction proceeds through a mechanism involving Ar–H oxidative addition, hydronickelation, and C–C reductive elimination. Further calculations indicate that a better anti-Markovnikov regioselectivity can be obtained for olefins substituted with more bulky alkyl groups, whereas a better Markovnikov regioselectivity can be achieved for more electron-deficient para-substituted styrenes. Further analysis shows that a secondary orbital overlap exists between Ni and the aryl group of styrene in the C–C reductive elimination transition state. This secondary orbital interaction is the key factor causing Markovnikov regioselectivity for vinylarenes. On the other hand, in the absence of this secondary orbital overlap the steric effect dominates the selectivity and, therefore, leads to the anti-Markovnikov products for alkyl-substituted alkenes.

Chemical synthesis of a cyclotide via intramolecular cyclization of peptide O-esters

Co-reporter:Ji-Shen Zheng;Hao-Nan Chang;Lei Liu

Science China Chemistry 2012 Volume 55( Issue 1) pp:64-69

Publication Date(Web):2012 January

DOI:10.1007/s11426-011-4434-4

Cyclotides constitute a fascinating family of circular proteins containing ca. 30 amino acid residues. They have a unique cyclic cysteine knot topology and exhibit remarkable thermal, chemical and enzymatic stabilities. These characteristics enable them to have a range of biological activities and promising pharmaceutical and agricultural applications. Here, we present a practical strategy for the chemical synthesis of cyclotides through the intramolecular ligation of fully unprotected peptide O-esters. This strategy involves the mild Fmoc solid-phase peptide synthesis of the peptide O-ester backbone, the head-to-tail cyclization of the cyclotide backbone by native chemical ligation, and the oxidative refolding to yield the natural knot protein. The simplicity and high efficiency of the strategy can be employed in the synthesis of artificial cyclotides for pharmaceutical applications.

A computational study of CX (X=H, C, F, Cl) bond dissociation enthalpies (BDEs) in polyhalogenated methanes and ethanes

Co-reporter:Jing Shi;Jian He ;Hua-Jing Wang

Journal of Physical Organic Chemistry 2011 Volume 24( Issue 1) pp:65-73

Publication Date(Web):

DOI:10.1002/poc.1704

Abstract

Bond dissociation enthalpies (BDEs) play a significant role in the photolysis of Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), which lead to the depletion of stratospheric ozone. In this work, we estimate the performance of Density Functional Theory (DFT) methods in calculating BDEs of CFCs and HCFCs, and find that DFTs are unreliable for this system. The reasons for the unreliability of DFT methods in this system are also concluded. Furthermore, composite ab initio methods G3 and G3B3 are demonstrated to accurately estimate BDEs of polyhalogenated lower alkanes. Eighty two experimental values from Comprehensive Handbook of Chemical Bond Energies (2007, 2nd edition) are re-evaluated. Eight of them are doubted as having a deviation exceeding 20.0 kJ/mol between the theoretical and experimental values. We also systematically predict the BDEs in polyhalogenated methanes and ethanes. A further study is conducted on their relationships of structures and properties. Copyright © 2010 John Wiley & Sons, Ltd.

A computational study of CS bond dissociation enthalpies in petroleum chemistry

Co-reporter:Jing Shi;Xi-Rui Hu;Shuang Liang

Heteroatom Chemistry 2011 Volume 22( Issue 2) pp:97-105

Publication Date(Web):

DOI:10.1002/hc.20662

Abstract

High-level theoretical methods (BMK, B3LYP, B98, B3P86, B3PW91, PBE1PBE, PBE1KIS, MPWPW91, MPW1KCIS, TPSS1KCIS, G3, G3//BMK, and CBS-Q) were utilized to study the carbon–sulfur bond dissociation enthalpies (BDEs) of hydrocarbons in petroleum chemistry. The performance of these methods was evaluated on the basis of a training set including the available experimental BDEs, and it was found that the BMK (Boese-Martin for Kinetics) method had the best agreement with experimental values. By using the BMK method to calculate CS BDEs of saturated hydrocarbon, the main factors, which determine the changing trend of BDE values, were discussed. Results revealed that the repulsive energies played an important role in determining a change in the trend of BDEs as well as the radical effect. Good agreements were obtained between further calculated BDEs and the experimental ones for CS and CO bonds. Moreover, the same calculation method was applied to predict CS BDEs for which the experimental values were still unavailable. A range of predicted bond dissociation enthalpy values were provided according to the calculations. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 22:97–105, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20662

Design of new neutral organic super-electron donors: a theoretical study

Co-reporter:Hua-Jing Wang;Ming Fang;Zhe Li ;Qing-Xiang Guo

Journal of Physical Organic Chemistry 2010 Volume 23( Issue 1) pp:75-83

Publication Date(Web):

DOI:10.1002/poc.1590

Abstract

For the purpose of designing new functional super-electron donors (SEDs), the structure and stability of analogous tetrathiafulvalene (TTF) compounds are investigated and compared with those of the parent TTF by quantum chemistry calculations. Density functional theory (DFT) method B3LYP in combination with the polarized continuum model (PCM) is employed to compute the standard redox potentials () of about 80 neutral organic SEDs in acetonitrile. Theoretical models are evaluated through correlation with 40 available experimental data. Excellent agreement between the theoretical predictions and experimental data is found with a mean absolute deviation of 0.08 V. Furthermore, we designed new species related to tetraazafulvalene (TAF) and evaluated their redox potential in search of new SEDs. Copyright © 2009 John Wiley & Sons, Ltd.

Theoretical Study on Acidities of (S)-Proline Amide Derivatives in DMSO and Its Implications for Organocatalysis

Co-reporter:Xiong-Yi Huang, Hua-Jing Wang and Jing Shi

The Journal of Physical Chemistry A 2010 Volume 114(Issue 2) pp:1068-1081

Publication Date(Web):December 23, 2009

DOI:10.1021/jp909043a

The acidities (pKa values) of proline amide derivatives are of great importance for understanding the catalytic activity of proline-based organocatalysts. The development of new catalysts could also benefit from the systematic study of the pKa values of these compounds. However, only a few pKa values of the proline-based organocatalysts are currently available due to the difficulty in experimentally measurements. In this work, we set out to study the pKa values of various proline amide derivatives with theoretical calculations. Different theoretical methods were evaluated and the combined method, B3PW91/6-311++G(3df,2p)//B3LYP/6-31+G(d)//HF//CPCM/UA0, was found to be the best one in reproducing the pKa values of structurally unrelated amides and amide derivatives in DMSO. The MAD and RMSE of the newly developed theoretical model equal to 0.98 and 1.3 pK units, respectively. The method also enabled the systematically study on various structural effects on pKa values of proline amide derivatives, such as the ZE-isomerization, remote substitution, and α-substitution effects, for the first time. The pKa values of a series of chiral amides were also studied in this work. Finally, we applied the theoretical method to predict a large number of proline-based organocatalysts and established an extensive acidity scale of the compounds.

A Theoretical Study on C−COOH Homolytic Bond Dissociation Enthalpies

Co-reporter:Jing Shi, Xiong-Yi Huang, Jun-Peng Wang and Run Li

The Journal of Physical Chemistry A 2010 Volume 114(Issue 21) pp:6263-6272

Publication Date(Web):May 7, 2010

DOI:10.1021/jp910498y

The knowledge of C−COOH homolytic bond dissociation enthalpies (BDEs) is of great importance in understanding various chemical and biochemical processes involving the decarboxylation reaction. In the present study, the density functional theory (DFT method), B3P86/6-311+ +G(2df,2p)//B3LYP/6-31+G(d), is found to be reliable to predict the C−COOH BDE of various structurally unrelated carboxylic acids. The mean absolute deviation (MAD) and root-mean-square deviation (rmsd) of this optimal method are equal to 2.0 and 2.5 kcal/mol, respectively. With the authorized theoretical protocol in hand, an extensive C−COOH BDE scale containing over 100 carboxylic acids has been established. The availability of this body of data enabled a detailed investigation of remote substituent effect on four types of carboxylic acids, including para-substituted benzoic acid, β-substituted cis-propenoic acid, β-substituted trans-propenoic acid, and substituted propiolic acid. Also with the C−COOH BDE data obtained in this work, an excellent linear relationship has been found between the C−COOH BDE of carboxylic acids and the C−H BDE of their hydrocarbon analogues. After comparing the energy barrier of the Pd-catalyzed decarboxylation reaction (ΔGdecarboxylation‡) with the related C−COOH BDE, a negative correlation between the ΔGdecarboxylation‡ and the C−COOH BDE was found.

New quinoline-based caging groups synthesized for photo-regulation of aptamer activity

Co-reporter:Yi Ming Li, Jing Shi, Rong Cai, XiaoYun Chen, Zhao Feng Luo, Qing Xiang Guo

Journal of Photochemistry and Photobiology A: Chemistry 2010 Volume 211(2–3) pp:129-134

Publication Date(Web):15 April 2010

DOI:10.1016/j.jphotochem.2010.02.009

A series of quinoline-based photo-removable protecting groups for photo-regulation of thrombin aptamer (HD1) activity were synthesized with improved caging and uncaging efficiency. Among them, 8-bromo-2-diazomethyl-7-hydroxyquinolinyl (BHQ-diazo, 1) chromophore was found to cage the HD1 with highest caging and restoration efficiency. Moreover, on the basis of the RP-HPLC and SPR analysis, BHQ was demonstrated to regulate HD1s specific affinity to target molecule with 3-fold photolysis sensitivity and about 40% percent higher uncaging efficiency than Bhc (6-bromo-7-hydroxycoumarin-4-ylmethyl) group. It was proposed that the development and use of quinoline derivative may provide a general strategy to photo-regulate oligonucleotide's activity with improved caging and uncaging efficiencies by the convenient non-site-specific caging method.

Two-Photon Fluorescent Probes of Biological Zn(II) Derived from 7-Hydroxyquinoline

Co-reporter:Xiao-Yun Chen, Jing Shi, Yi-Ming Li, Feng-Liang Wang, Xu Wu, Qing-Xiang Guo and Lei Liu

Organic Letters 2009 Volume 11(Issue 19) pp:4426-4429

Publication Date(Web):September 1, 2009

DOI:10.1021/ol901787w

A new fluorescent probe for monitoring Zn2+ was synthesized based on the structure of 7-hydroxyquinoline. Compared with 8-substituted quinolines, the new probe exhibited higher selectivity for Zn2+ over Cd2+. Its fluorescence enhancement (14-fold) and nanomolar range sensitivity (Kd = 0.117 nM) were favorable toward biological applications. Experiments also showed that a cell-permeable derivative of the new probe was potentially useful for two-photon imaging in living cells.

Heterocyclic analogs of phenol as novel potential antioxidants

Co-reporter:Jing Shi;Shuang Liang;Ye-Su Feng;Hua-Jing Wang ;Qing-Xiang Guo

Journal of Physical Organic Chemistry 2009 Volume 22( Issue 11) pp:1038-1047

Publication Date(Web):

DOI:10.1002/poc.1556

Abstract

Five density functional theory (DFT) methods including B3LYP, B3PW91, MPW1K, MPWB, TPSS1KCIS have been evaluated by comparing with the experimental OH bond dissociation enthalpies (BDEs) of substituted phenols. B3PW91 is found to be the best method, for which the calculation error was 3.62 kJ/mol. Subsequently, the BDEs (OH) of hydroxyl groups on five- and six-membered heteroatomic aromatic rings have been calculated using the (RO)B3PW91/6-311++G(2df,2p)//(U)B3LYP/6-311g(d,p) procedure. In addition, the ionization energy (IE) and proton affinity [PA(O⁻)] of these compounds have also been examined. On the basis of our theoretical study, a series of imidazolols, thiazolols, and oxazolols were studied to assess their antioxidant activities. It was found that 5-oxazolol could be a promising novel antioxidant precursor. Copyright © 2009 John Wiley & Sons, Ltd.

Photoregulation of thrombin aptamer activity using Bhc caging strategy

Co-reporter:YiMing Li, Jing Shi, ZhaoFeng Luo, Hao Jiang, XiaoYun Chen, FengLiang Wang, Xu Wu, QingXiang Guo

Bioorganic & Medicinal Chemistry Letters 2009 Volume 19(Issue 18) pp:5368-5371

Publication Date(Web):15 September 2009

DOI:10.1016/j.bmcl.2009.07.128

Thrombin aptamer was attempted to cage with Bhc (6-bromo-7-hydroxycoumarin-4-ylmethyl) group for controlling its specific affinity to target molecular through photolysis. By multiple-caging strategy, aptamer could be rendered biologically inert and partially restored with subsequently illumination. This provides a convenient method for photoregulating aptamer activity with exact spatiotemporal resolution.

Theoretical study on C32 fullerenes and their endohedral complexes with noble gas atoms

Co-reporter:Yi-Ming Chen, Jing Shi, Lei Rui, Qing-Xiang Guo

Journal of Molecular Structure: THEOCHEM 2009 Volume 907(1–3) pp:104-108

Publication Date(Web):15 August 2009

DOI:10.1016/j.theochem.2009.04.038

Non-isolated pentagon fullerenes with a series of special physical and chemical properties have potential applications in the fields of pharmaceutics, chemical catalysis and superconducting materials. On the basis of theoretical calculations, stabilities and aromaticities of pure and doped C32 fullerene isomers are calculated at B3LYP/6-31+G(d) level systematically for the first time. Formation enthalpies and BSSE-corrected encapsulation energies of endohedral fullerenes are also studied at the same level of theory, the changes of corrected single point energy sequence are possibly useful in controlling the proportions of different isomers in chemical synthesis.

Theoretical studies on oxidation potentials of organophosphorus compounds

Co-reporter:Jing Shi, Yuan-Long Zhao, Hua-Jing Wang, Lei Rui, Qing-Xiang Guo

Journal of Molecular Structure: THEOCHEM 2009 Volume 902(1–3) pp:66-71

Publication Date(Web):30 May 2009

DOI:10.1016/j.theochem.2009.02.014

A theoretical method was developed, which can successfully predict the oxidation potentials of a number of amines in CH3CN with a precision about 0.08 V. Using this method we calculated the oxidation potential values of diverse types of organophosphorus compounds in CH3CN. With these theoretical values, a scale of reliable oxidation values was constructed for the first time to organophosphorus compounds. These oxidation potential values would be helpful to synthetic chemists who need to select apt organophosphorus reagents for electrochemistry reactions. On the basis of these oxidation potential values, we also studied, for the first time, some interesting topics such as the substituent effects on the oxidation potential values of various types of organophosphorus. The differences between oxidation potential values of organophosphorus and organic amines were also discussed.

Diaminodiacid-based solid-phase synthesis of all-hydrocarbon stapled α-helical peptides

Co-reporter:Feng-Liang Wang, Ye Guo, Si-Jian Li, Qing-Xiang Guo, Jing Shi and Yi-Ming Li

Organic & Biomolecular Chemistry 2015 - vol. 13(Issue 22) pp:NaN6290-6290

Publication Date(Web):2015/04/29

DOI:10.1039/C5OB00741K

Thiol-assisted one-pot synthesis of peptide/protein C-terminal thioacids from peptide/protein hydrazides at neutral conditions

Co-reporter:Chenchen Chen, Yichao Huang, Ling Xu, Yong Zheng, Huajian Xu, Qingxiang Guo, Changlin Tian, Yiming Li and Jing Shi

Organic & Biomolecular Chemistry 2014 - vol. 12(Issue 46) pp:NaN9418-9418

Publication Date(Web):2014/10/01

DOI:10.1039/C4OB01885K

Accurate prediction of rate constants of Diels–Alder reactions and application to design of Diels–Alder ligation

Co-reporter:Shi-Ya Tang, Jing Shi and Qing-Xiang Guo