Co-reporter:Shi-Kai Xiang, Guolin Wu, Bo Zhang, Yuxin Cui, Ning Jiao
Tetrahedron Letters 2012 Volume 53(Issue 29) pp:3802-3804
Publication Date(Web):18 July 2012
DOI:10.1016/j.tetlet.2012.05.053
The alkenylation of indoles with α,β-unsaturated ketones through a tandem addition and oxidative dehydrogenation strategy has been developed. This method provides an alternative approach for C3 alkenylation of indoles with α,β-unsaturated ketones. Using inexpensive and readily available BF3·Et2O and an ammonium salt as the efficient cocatalyst constitutes the attractive advantage of this reaction.
Co-reporter:Bo Zhang, Shi-Kai Xiang, Li−He Zhang, Yuxin Cui, and Ning Jiao
Organic Letters 2011 Volume 13(Issue 19) pp:5212-5215
Publication Date(Web):September 8, 2011
DOI:10.1021/ol202090a
An organocatalytic enantioselective intermolecular oxidative dehydrogenative α-alkylation of aldehydes via benzylic C–H bond activation has been developed. The asymmetric reaction is smoothly fulfilled by using simple and green molecular oxygen as the oxidant. Two hydrogen dissociations make this transformation more environmentally benign because of high atom efficiency.
Co-reporter:Zhuangzhi Shi, Yuxin Cui and Ning Jiao
Organic Letters 2010 Volume 12(Issue 13) pp:2908-2911
Publication Date(Web):June 1, 2010
DOI:10.1021/ol1007839
A palladium-catalyzed direct dehydrogenative annulation (DDA) of indolecarboxamides with internal alkynes via C−H and N−H bond cleavage using air as the oxidant was developed. With this method, both β- and γ-carbolinones can be easily prepared under the mild conditions.
Co-reporter:Long Zhang, Haixia Jiang, Xingxin Cao, Huiyun Zhao, Fan Wang, Yuxin Cui, Biao Jiang
European Journal of Medicinal Chemistry 2009 Volume 44(Issue 10) pp:3961-3972
Publication Date(Web):October 2009
DOI:10.1016/j.ejmech.2009.04.025
To better use gossypol to find promising anticancer compounds, a series of new and known bis-Schiff base analogs of chiral gossypol were synthesized, and their anticancer activity on HeLa, U87 and M85 cells was tested. The results showed that through a simple chemical modification, less active (+)-gossypol could be converted into more active derivatives. When compared with (−)-gossypol, many more potent compounds that could be the promising anticancer agents were found, and some of them were more potent than the anticancer drug Cisplatin against all three cancer cell lines. By eliminating target functional groups, we observed that the major contributor to the anticancer activity of chiral gossypol seemed to be the phenolic groups, and not the aldehyde groups. Through comprehensive analysis of chiral gossypol analogs, the structure–activity relationships were elaborated.Synthesis of chiral gossypol analogs and their anticancer activity on HeLa, U87 and M85 cells as well as structure–activity relationships were elaborated.
Co-reporter:Long Zhang, Xing Xin Cao, Hai Xia Jiang, Biao Jiang, Yu Xin Cui
Chinese Chemical Letters 2009 Volume 20(Issue 6) pp:716-719
Publication Date(Web):June 2009
DOI:10.1016/j.cclet.2008.12.049
To investigate the structural form of gossypol and gossypolone Schiff's bases, seven relevant Schiff's bases were synthesized and the electrospray ionization–tandem mass spectrometry (ESI–MS/MS) with low-energy collision-induced dissociation was used to analyze their fragmentations. A common fragmentation pathway with the loss of RNH2 from those schiff's bases quasi-molecular ions was observed and proposed on the basis of their MS/MS spectra data. This common pathway indicated that those Schiff's bases existed mainly as the enamine form not the imine form previously showed in most reports.
Co-reporter:Long Zhang;WeiWei He;YongMin Liang
Science China Chemistry 2009 Volume 52( Issue 7) pp:937-942
Publication Date(Web):2009 July
DOI:10.1007/s11426-009-0032-0
While studying the electrophilic cyclization of acetylenic malonates in synthesizing malonate indene derivatives with high regio and stereo-selectivity, we found that the CH2 and CH3 protons of two COOCH2CH3 groups in some diethyl malonate indene derivatives showed very interesting spin-spin coupling and signal multiplicity. To explain those phenomena, we synthesized several diethyl malonate indene derivatives, and then used 1H NMR spectra and molecular modeling to investigate the CH2CH3 spin system of these two COOCH2CH3 groups in detail. The results showed that the spin systems of CH3CH2 of the two COOCH2CH3 groups in those compounds may exist in different froms (AMX3, ABX3 and A2X3), and the effect of the aromatic ring induced by the phenyl group at the end of the triple bond is the main reason responsible for those phenomena.
Co-reporter:Lei Zhang, Bing Jia, Chang Feng Hu, Fan Wang, Yu Xin Cui
Chinese Chemical Letters 2008 Volume 19(Issue 7) pp:801-804
Publication Date(Web):July 2008
DOI:10.1016/j.cclet.2008.04.046
A series of new O6-BG derivatives (14–21,23–30) were synthesized as inactivators of O6-Alkylguanine-DNA alkyltransferase (AGT), and their ability to inhibit AGT was preliminary evaluated by MTT with O6-BG as the control. The result suggested compound 30 displayed a higher activity than O6-BG.
Co-reporter:Chang Feng Hu, Chuan Jun Zhu, Yan Feng Gao, Xuan Shao, Rui Wang, Yu Xin Cui
Chinese Chemical Letters 2008 Volume 19(Issue 12) pp:1479-1482
Publication Date(Web):December 2008
DOI:10.1016/j.cclet.2008.09.023
A series of analogs of endomorphin-2 (EM-2) with phenylglycine (Phg) in position 3 or 4 were synthesized. In electrospray ionization Fourier transform ion cyclotron resonance (ESI-FT-ICR) MS/MS spectra of these compounds, some b, y, a, and internal ions were observed and slight mass differences between the calculated and observed results are obtained. Their sequences were derived successfully. However, the MS/MS patterns of these analogs with DPhg and LPhg were very similar. It is hard to distinguish them by MS/MS spectra. Moreover, if the third position was substituted by phenylglycine (l or d), a rearrangement could occur in MS/MS experiment to lose proline residue.
Co-reporter:ChuanJun Zhu;ChangFeng Hu;Xuan Shao;JinLong Yao
Science China Chemistry 2008 Volume 51( Issue 1) pp:41-45
Publication Date(Web):2008 January
DOI:10.1007/s11426-007-0123-8
In this paper, a series of C-terminal modified analogs of endomorphin-2 is investigated using ESI-FT-ICR-MS. Some b, y″, a, and internal ions are found in the CID spectra and slight mass differences between the calculated and observed results are obtained. Moreover, if the C-terminal modified group is t-butyloxy, it can lose butene through McLafferty rearrangement. FT-ICR MS shows its power in peptide sequencing successfully helping us obtain the structure of peptide analogs.
Co-reporter:Xuan Shao, Yanfeng Gao, Chuanjun Zhu, Xuehui Liu, Jinlong Yao, Yuxin Cui, Rui Wang
Bioorganic & Medicinal Chemistry 2007 Volume 15(Issue 10) pp:3539-3547
Publication Date(Web):15 May 2007
DOI:10.1016/j.bmc.2007.02.050
We investigated a series of conformations of endomorphin-2 (EM-2) analogs substituted by phenylglycine (Phg) and homophenylalanine (Hfe) in the position 3 or 4 by two-dimensional 1H NMR spectroscopy and molecular modeling. Evaluating the aromatic interactions and the dihedral angles in these phenylalanine mimics, we have observed that the conformations in trans isomer have varied from extended to folded as bioactivity decreases. It is suggested that the flexibility of aromatic side chain affects the backbone of EM-2 to adopt folded structures, which may block the ligands in binding to μ-opioid receptor.The conformations of EM-2 analogs varied from extended to folded structure as bioactivity decreases.
Co-reporter:Yuxin Cui;Runtao Li;Ze-Mei Ge;Chunhui Yang;Qin Li
Magnetic Resonance in Chemistry 2006 Volume 44(Issue 7) pp:720-723
Publication Date(Web):2 MAY 2006
DOI:10.1002/mrc.1808
Compounds 1–7 form a novel group of dithiocarbamates, first synthesized from the reaction of a series of primary amines with carbon disulfide and 3-bromo ethyl pyruvate in the presence of anhydrous potassium phosphate. Structure elucidation of this group of compounds was accomplished using extensive 1D and 2D NMR spectroscopic studies, including 1H, 13C, COSY, NOESY, HSQC, and gHMBC experiments. The distinction between the linear structures I, II and the cyclic structure III was made mainly on the basis of the analysis of the cross peak between H-2 and H-4a in the COSY spectra, in combination with the long-range correlation between H-2 and C-4, 6 in the gHMBC spectra. Copyright © 2006 John Wiley & Sons, Ltd.