Co-reporter:Lei Han, Ji-Bao Xia, Lin You, Chuo Chen
Tetrahedron 2017 Volume 73, Issue 26(Issue 26) pp:
Publication Date(Web):29 June 2017
DOI:10.1016/j.tet.2017.05.008
Photoexcited arylketones catalyze the direct chlorination of C(sp3)–H groups by N- chlorosuccinimide. Acetophenone is the most effective catalyst for functionalization of unactivated C–H groups while benzophenone provides better yields for benzylic C–H functionalization. Activation of both acetophenone and benzophenone can be achieved by irradiation with a household compact fluorescent lamp. This light-dependent reaction provides a better control of the reaction as compared to the traditional chlorination methods that proceed through a free radical chain propagation mechanism.Download high-res image (82KB)Download full-size image
Co-reporter:Zhiqiang Ma, Lin You, and Chuo Chen
The Journal of Organic Chemistry 2017 Volume 82(Issue 1) pp:731-736
Publication Date(Web):December 9, 2016
DOI:10.1021/acs.joc.6b02266
Stereoselective construction of the 1,3-diazaspiro[4.4]nonane core skeleton of massadine and related dimeric pyrrole–imidazole alkaloids is a synthetic challenge. We describe herein the synthesis of all C13/14 diastereomers of this spiro molecule through controlled oxidation and epimerization of the C13 spirocenter under mild acidic conditions.
Co-reporter:Dr. Zhiqiang Ma;Dr. Xiao Wang;Dr. Yuyong Ma;Dr. Chuo Chen
Angewandte Chemie International Edition 2016 Volume 55( Issue 15) pp:4763-4766
Publication Date(Web):
DOI:10.1002/anie.201600007
Abstract
Axinellamines A and B are broad-spectrum antibacterial pyrrole–imidazole alkaloids that have a complex polycyclic skeleton. A new asymmetric synthesis of these marine sponge metabolites is described herein, featuring an oxidative rearrangement and an anchimeric chlorination reaction.
Co-reporter:Dr. Zhiqiang Ma;Dr. Xiao Wang;Dr. Yuyong Ma;Dr. Chuo Chen
Angewandte Chemie 2016 Volume 128( Issue 15) pp:4841-4844
Publication Date(Web):
DOI:10.1002/ange.201600007
Abstract
Axinellamines A and B are broad-spectrum antibacterial pyrrole–imidazole alkaloids that have a complex polycyclic skeleton. A new asymmetric synthesis of these marine sponge metabolites is described herein, featuring an oxidative rearrangement and an anchimeric chlorination reaction.
Co-reporter:Brett Lomenick, Heping Shi, Jing Huang, Chuo Chen
Bioorganic & Medicinal Chemistry Letters 2015 Volume 25(Issue 21) pp:4976-4979
Publication Date(Web):1 November 2015
DOI:10.1016/j.bmcl.2015.03.007
β-Sitosterol is the most abundant plant sterol in the human diet. It is also the major component of several traditional medicines, including saw palmetto and devil’s claw. Although β-sitosterol is effective against enlarged prostate in human clinical trials and has anti-cancer and anti-inflammatory activities, the mechanisms of action are poorly understood. Here, we report the identification of two new binding proteins for β-sitosterol that may underlie its beneficial effects.
Co-reporter:Heping Shi, Saptarshi De, Qiaoling Wang, Shuanhu Gao, Xiao Wang, Chuo Chen
Tetrahedron Letters 2015 Volume 56(Issue 23) pp:3225-3227
Publication Date(Web):3 June 2015
DOI:10.1016/j.tetlet.2014.12.054
We report herein the synthesis of a fully functionalized B,C,D-ring system of lancifodilactone F. The key transformations involve an arene–olefin meta-photocycloaddition reaction and a palladium-catalyzed oxidative C–C cleavage reaction to establish its B,C-rings.
Co-reporter:Xiaolei Wang, Chuo Chen
Tetrahedron 2015 Volume 71(Issue 22) pp:3690-3693
Publication Date(Web):3 June 2015
DOI:10.1016/j.tet.2014.10.027
The biosynthesis of dimeric pyrrole–imidazole alkaloids is likely mediated by enzyme-catalyzed reversible single-electron transfer (SET) cycloaddition. We now show that Ir(ppy)3 can promote SET-mediated formal [2+2] and [4+2] cycloaddition reactions of pyrrole–imidazole alkaloids-related substrates under photolytic conditions. This biomimetic approach is useful for the construction of the core skeleton of nakamuric acid and sceptrin.
Co-reporter:Yuyong Ma, Saptarshi De, Chuo Chen
Tetrahedron 2015 Volume 71(Issue 8) pp:1145-1173
Publication Date(Web):25 February 2015
DOI:10.1016/j.tet.2014.11.056
Co-reporter:Jiaxi Wu;Heping Shi;Zhijian J. Chen
PNAS 2015 Volume 112 (Issue 29 ) pp:8947-8952
Publication Date(Web):2015-07-21
DOI:10.1073/pnas.1507317112
Cyclic GMP-AMP containing a unique combination of mixed phosphodiester linkages (2′3′-cGAMP) is an endogenous second messenger
molecule that activates the type-I IFN pathway upon binding to the homodimer of the adaptor protein STING on the surface of
endoplasmic reticulum membrane. However, the preferential binding of the asymmetric ligand 2′3′-cGAMP to the symmetric dimer
of STING represents a physicochemical enigma. Here we show that 2′3′-cGAMP, but not its linkage isomers, adopts an organized
free-ligand conformation that resembles the STING-bound conformation and pays low entropy and enthalpy costs in converting
into the active conformation. Our results demonstrate that analyses of free-ligand conformations can be as important as analyses
of protein conformations in understanding protein–ligand interactions.
Co-reporter:Ji-Bao Xia, Chen Zhu and Chuo Chen
Chemical Communications 2014 vol. 50(Issue 79) pp:11701-11704
Publication Date(Web):14 Aug 2014
DOI:10.1039/C4CC05650G
Photoexcited acetophenone can catalyze the fluorination of unactivated C(sp3)–H groups. While acetophenone, a colorless oil, only has a trace amount of absorption in the visible light region, its photoexcitation can be achieved by irradiation with light generated by a household compact fluorescent lamp (CFL). This operational simple method provides improved substrate scope for the direct incorporation of a fluorine atom into simple organic molecules. CFL-irradiation can also be used to promote certain classic UV-promoted photoreactions of colorless monoarylketones and enones/enals.
Co-reporter:Chen Zhu, Ji-Bao Xia, and Chuo Chen
Organic Letters 2014 Volume 16(Issue 1) pp:247-249
Publication Date(Web):December 6, 2013
DOI:10.1021/ol403245r
Bleach oxidizes trimethylsilyl cyanide to generate an electrophilic cyanating reagent that readily reacts with an amine nucleophile. This oxidative N-cyanation reaction allows for the preparation of disubstituted cyanamides from amines without using highly toxic cyanogen halides.
Co-reporter:Xiao Wang, Zhiqiang Ma, Xiaolei Wang, Saptarshi De, Yuyong Ma and Chuo Chen
Chemical Communications 2014 vol. 50(Issue 63) pp:8628-8639
Publication Date(Web):07 May 2014
DOI:10.1039/C4CC02290D
The pyrrole–imidazole alkaloids are a group of structurally unique and biologically interesting marine sponge metabolites. Among them, the cyclic dimers have caught synthetic chemists' attention particularly. Numerous synthetic strategies have been developed and various biosynthetic hypotheses have been proposed for these fascinating natural products. We discuss herein the synthetic approaches and the biosynthetic insights obtained from these studies.
Co-reporter:Chen Zhu, Ji-Bao Xia, Chuo Chen
Tetrahedron Letters 2014 Volume 55(Issue 1) pp:232-234
Publication Date(Web):1 January 2014
DOI:10.1016/j.tetlet.2013.11.012
We describe an oxidative Strecker reaction that allows for direct cyanation of para-methoxyphenyl (PMP)-protected primary amines. A vanadium(V) complex was used as the catalyst and TBHP as the oxidant. The cyanation occurs at the α-C position bearing either an alkyl or an aromatic group. This method provides a direct access to α-aminonitrile from amines with one-carbon extension.
Co-reporter:Zhiqiang Ma;Xiaolei Wang;Xiao Wang;Rodrigo A. Rodriguez;Curtis E. Moore;Shuanhu Gao;Xianghui Tan;Yuyong Ma;Phil S. Baran;Arnold L. Rheingold
Science 2014 Volume 346(Issue 6206) pp:219-224
Publication Date(Web):10 Oct 2014
DOI:10.1126/science.1255677
Abstract
Cycloaddition is an essential tool in chemical synthesis. Instead of using light or heat as a driving force, marine sponges promote cycloaddition with a more versatile but poorly understood mechanism in producing pyrrole–imidazole alkaloids sceptrin, massadine, and ageliferin. Through de novo synthesis of sceptrin and massadine, we show that sponges may use single-electron oxidation as a central mechanism to promote three different types of cycloaddition. Additionally, we provide surprising evidence that, in contrast to previous reports, sceptrin, massadine, and ageliferin have mismatched chirality. Therefore, massadine cannot be an oxidative rearrangement product of sceptrin or ageliferin, as is commonly believed. Taken together, our results demonstrate unconventional chemical approaches to achieving cycloaddition reactions in synthesis and uncover enantiodivergence as a new biosynthetic paradigm for natural products.
Co-reporter:Ji-Bao Xia ; Chen Zhu
Journal of the American Chemical Society 2013 Volume 135(Issue 46) pp:17494-17500
Publication Date(Web):November 3, 2013
DOI:10.1021/ja410815u
We report herein an operationally simple method for the direct conversion of benzylic C–H groups to C–F. We show that visible light can activate diarylketones to abstract a benzylic hydrogen atom selectively. Adding a fluorine radical donor yields the benzylic fluoride and regenerates the catalyst. The selective formation of mono- and difluorination products can be achieved by catalyst control. 9-Fluorenone catalyzes benzylic C–H monofluorination, while xanthone catalyzes benzylic C–H difluorination. The scope and efficiency of this new C–H fluorination method are significantly better than those of the existing methods. This is also the first report of selective C–H gem-difluorination.
Co-reporter:Xiaolei Wang ; Jesung Moon ; Michael E. Dodge ; Xinchao Pan ; Lishu Zhang ; Jordan M. Hanson ; Rubina Tuladhar ; Zhiqiang Ma ; Heping Shi ; Noelle S. Williams ; James F. Amatruda ; Thomas J. Carroll ; Lawrence Lum
Journal of Medicinal Chemistry 2013 Volume 56(Issue 6) pp:2700-2704
Publication Date(Web):March 11, 2013
DOI:10.1021/jm400159c
Porcupine is a member of the membrane-bound O-acyltransferase family of proteins. It catalyzes the palmitoylation of Wnt proteins, a process required for their secretion and activity. We recently disclosed a class of small molecules (IWPs) as the first reported Porcn inhibitors. We now describe the structure–activity relationship studies and the identification of subnanomolar inhibitors. We also report herein the effects of IWPs on Wnt-dependent developmental processes, including zebrafish posterior axis formation and kidney tubule formation.
Co-reporter:Xiao Wang, Xiaolei Wang, Xianghui Tan, Jianming Lu, Kevin W. Cormier, Zhiqiang Ma, and Chuo Chen
Journal of the American Chemical Society 2012 Volume 134(Issue 45) pp:18834-18842
Publication Date(Web):October 17, 2012
DOI:10.1021/ja309172t
The pyrrole–imidazole alkaloids have fascinated chemists for decades because of their unique structures. The high nitrogen and halogen contents and the densely functionalized skeletons make their laboratory synthesis challenging. We describe herein an oxidative method for accessing the core skeletons of two classes of pyrrole–imidazole dimers. This synthetic strategy was inspired by the putative biosynthesis pathways and its development was facilitated by computational studies. Using this method, we have successfully prepared ageliferin, bromoageliferin, and dibromoageliferin in their natural enantiomeric form.
Co-reporter:Ji-Bao Xia, Kevin W. Cormier and Chuo Chen
Chemical Science 2012 vol. 3(Issue 7) pp:2240-2245
Publication Date(Web):13 Apr 2012
DOI:10.1039/C2SC20178J
Vanadium complexes have been used extensively to catalyze olefin and alcohol oxidation. However, their application in C–H oxidation has not been well-studied. We report herein that commercially available Cp2VCl2 catalyzes benzylic C–H oxidation selectively and effectively, giving no aromatic oxidation products.
Co-reporter:Xiao Wang ; Zhiqiang Ma ; Jianming Lu ; Xianghui Tan
Journal of the American Chemical Society 2011 Volume 133(Issue 39) pp:15350-15353
Publication Date(Web):September 4, 2011
DOI:10.1021/ja207386q
We describe herein an asymmetric synthesis of ageliferin. A Mn(III)-mediated oxidative radical cyclization reaction was used as the key step to construct the core skeleton of this pyrrole–imidazole dimer. This approach resembles the biogenic [4 + 2] dimerization in an intramolecular fashion.
Co-reporter:Zhiqiang Ma, Jianming Lu, Xiao Wang and Chuo Chen
Chemical Communications 2011 vol. 47(Issue 1) pp:427-429
Publication Date(Web):16 Sep 2010
DOI:10.1039/C0CC02214D
We propose herein an alternative biosynthetic pathway for palau'amine in order to resolve the stereochemical issue from the original Kinnel–Scheuer hypothesis. Furthermore, we use this revised hypothesis as a guide toward the laboratory synthesis of palau'amine.
Co-reporter:Shuanhu Gao ; Qiaoling Wang ; Lily Jun-Shen Huang ; Lawrence Lum
Journal of the American Chemical Society 2009 Volume 132(Issue 1) pp:371-383
Publication Date(Web):December 10, 2009
DOI:10.1021/ja908626k
Nakiterpiosin and nakiterpiosinone are two related C-nor-D-homosteroids isolated from the sponge Terpios hoshinota that show promise as anticancer agents. We have previously described the asymmetric synthesis and revision of the relative configuration of nakiterpiosin. We now provide detailed information on the stereochemical analysis that supports our structure revision and the synthesis of the originally proposed and revised nakiterpiosin. In addition, we herein describe a refined approach for the synthesis of nakiterpiosin, the first synthesis of nakiterpiosinone, and preliminary mechanistic studies of nakiterpiosin’s action in mammalian cells. Cells treated with nakiterpiosin exhibit compromised formation of the primary cilium, an organelle that functions as an assembly point for components of the Hedgehog signal transduction pathway. We provide evidence that the biological effects exhibited by nakiterpiosin are mechanistically distinct from those of well-established antimitotic agents such as taxol. Nakiterpiosin may be useful as an anticancer agent in those tumors resistant to existing antimitotic agents and those dependent on Hedgehog pathway responses for growth.
Co-reporter:Jianming Lu, Zhiqiang Ma, Jen-Chieh Hsieh, Chih-Wei Fan, Baozhi Chen, Jamie C. Longgood, Noelle S. Williams, James F. Amatruda, Lawrence Lum, Chuo Chen
Bioorganic & Medicinal Chemistry Letters 2009 Volume 19(Issue 14) pp:3825-3827
Publication Date(Web):15 July 2009
DOI:10.1016/j.bmcl.2009.04.040
Suppression of oncogenic Wnt-mediated signaling holds promise as an anti-cancer therapeutic strategy. We previously reported a novel class of small molecules (IWR-1/2, inhibitors of Wnt response) that antagonize Wnt signaling by stabilizing the Axin destruction complex. Herein, we present the results of structure-activity relationship studies of these compounds.SAR studies of IWR-1 are described.
Co-reporter:Xianghui Tan Dr. Dr.
Angewandte Chemie International Edition 2006 Volume 45(Issue 26) pp:
Publication Date(Web):31 MAY 2006
DOI:10.1002/anie.200601208
In control: A cyclization reaction of an allylic β-imidazolinonyl-β-ketoester 1 is carried out in a MnIII-promoted radical cascade. The reaction pathway (5-exo/6-endo or 5-exo/5-exo) can be directed to construct the central cyclopentyl and cyclohexenyl core skeletons (2 and 3) of two classes of oroidin dimers with regiocontrol. An oxidative rearrangement can also be used to convert 2 into 3. PG=protecting group.
Co-reporter:Xianghui Tan Dr. Dr.
Angewandte Chemie 2006 Volume 118(Issue 26) pp:
Publication Date(Web):31 MAY 2006
DOI:10.1002/ange.200601208
Unter Kontrolle: Die Cyclisierung eines allylischen β-Imidazolinonyl-β-ketoesters 1 wird in Form einer MnIII-vermittelten Radikalkaskade durchgeführt. Dabei kann der Reaktionsverlauf (5-exo/6-endo oder 5-exo/5-exo) in Richtung der zentralen Cyclopentyl- und Cyclohexenylgerüste (3 bzw. 2) zweier Klassen von Oroidindimeren gesteuert werden. 2 kann auch durch oxidative Umlagerung in 3 überführt werden. PG=Schutzgruppe.
Co-reporter:Xu Zhang, Heping Shi, Jiaxi Wu, Xuewu Zhang, ... Zhijian J. Chen
Molecular Cell (25 July 2013) Volume 51(Issue 2) pp:226-235
Publication Date(Web):25 July 2013
DOI:10.1016/j.molcel.2013.05.022
•2′3′-cGAMP is an endogenous second messenger produced by mammalian cells•2′3′-cGAMP is a high-affinity ligand for STING•2′3′-cGAMP is a potent inducer of type I interferons•2′3′-cGAMP binding induces conformational changes of STINGThe presence of microbial or self DNA in the cytoplasm of mammalian cells is a danger signal detected by the DNA sensor cyclic-GMP-AMP (cGAMP) synthase (cGAS), which catalyzes the production of cGAMP that in turn serves as a second messenger to activate innate immune responses. Here we show that endogenous cGAMP in mammalian cells contains two distinct phosphodiester linkages, one between 2′-OH of GMP and 5′-phosphate of AMP, and the other between 3′-OH of AMP and 5′-phosphate of GMP. This molecule, termed 2′3′-cGAMP, is unique in that it binds to the adaptor protein STING with a much greater affinity than cGAMP molecules containing other combinations of phosphodiester linkages. The crystal structure of STING bound to 2′3′-cGAMP revealed the structural basis of this high-affinity binding and a ligand-induced conformational change in STING that may underlie its activation.Download high-res image (296KB)Download full-size image
Co-reporter:Lin You, Chengwei Zhang, Nageswari Yarravarapu, Lorraine Morlock, Xiaolei Wang, Lishu Zhang, Noelle S. Williams, Lawrence Lum, Chuo Chen
Bioorganic & Medicinal Chemistry Letters (15 December 2016) Volume 26(Issue 24) pp:
Publication Date(Web):15 December 2016
DOI:10.1016/j.bmcl.2016.11.012
The acyltransferase Porcupine (Porcn) is essential for the secretion of Wnt proteins which contribute to embryonic development, tissue regeneration, and tumorigenesis. We have previously discovered four molecular scaffolds harboring Porcn-inhibitory activity. Comparison of their structures led to the identification of a general scaffold that can be readily assembled by modular synthesis. We report herein the development of a triazole version of this new class of Porcn inhibitors. This study yielded IWP-O1, a Porcn inhibitor with an EC50 value of 80 pM in a cultured cell reporter assay of Wnt signaling. Additionally, IWP-O1 has significantly improved metabolic stability over our previously reported Porcn inhibitors.
Co-reporter:Zhiqiang Ma, Jianming Lu, Xiao Wang and Chuo Chen
Chemical Communications 2011 - vol. 47(Issue 1) pp:NaN429-429
Publication Date(Web):2010/09/16
DOI:10.1039/C0CC02214D
We propose herein an alternative biosynthetic pathway for palau'amine in order to resolve the stereochemical issue from the original Kinnel–Scheuer hypothesis. Furthermore, we use this revised hypothesis as a guide toward the laboratory synthesis of palau'amine.
Co-reporter:Xiao Wang, Zhiqiang Ma, Xiaolei Wang, Saptarshi De, Yuyong Ma and Chuo Chen
Chemical Communications 2014 - vol. 50(Issue 63) pp:NaN8639-8639
Publication Date(Web):2014/05/07
DOI:10.1039/C4CC02290D
The pyrrole–imidazole alkaloids are a group of structurally unique and biologically interesting marine sponge metabolites. Among them, the cyclic dimers have caught synthetic chemists' attention particularly. Numerous synthetic strategies have been developed and various biosynthetic hypotheses have been proposed for these fascinating natural products. We discuss herein the synthetic approaches and the biosynthetic insights obtained from these studies.
Co-reporter:Ji-Bao Xia, Chen Zhu and Chuo Chen
Chemical Communications 2014 - vol. 50(Issue 79) pp:NaN11704-11704
Publication Date(Web):2014/08/14
DOI:10.1039/C4CC05650G
Photoexcited acetophenone can catalyze the fluorination of unactivated C(sp3)–H groups. While acetophenone, a colorless oil, only has a trace amount of absorption in the visible light region, its photoexcitation can be achieved by irradiation with light generated by a household compact fluorescent lamp (CFL). This operational simple method provides improved substrate scope for the direct incorporation of a fluorine atom into simple organic molecules. CFL-irradiation can also be used to promote certain classic UV-promoted photoreactions of colorless monoarylketones and enones/enals.
Co-reporter:Xiaolei Wang, Yang Gao, Zhiqiang Ma, Rodrigo A. Rodriguez, Zhi-Xiang Yu and Chuo Chen
Inorganic Chemistry Frontiers 2015 - vol. 2(Issue 8) pp:NaN984-984
Publication Date(Web):2015/06/12
DOI:10.1039/C5QO00165J
Sceptrins and nakamuric acid are structurally unique antibiotics isolated from marine sponges. Recent studies suggest that the biosynthesis of these dimeric pyrrole–imidazole alkaloids involves a single-electron transfer (SET)-promoted [2 + 2] cycloaddition to form their cyclobutane core skeletons. We describe herein the biomimetic syntheses of racemic sceptrin and nakamuric acid. We also report the asymmetric syntheses of sceptrin, bromosceptrin, and dibromosceptrin in their natural enantiomeric form. We further provide mechanistic insights into the pathway selectivity of the SET-promoted [2 + 2] and [4 + 2] cycloadditions that lead to the divergent formation of the sceptrin and ageliferin core skeletons. Both the [2 + 2] and [4 + 2] cycloadditions are stepwise reactions, with the [2 + 2] pathway kinetically and thermodynamically favored over the [4 + 2] pathway. For the [2 + 2] cycloaddition, the dimerization of pyrrole–imidazole monomers is rate-limiting, whereas for the [4 + 2] cycloaddition, the cyclization is the slowest step.
Co-reporter:Ji-Bao Xia, Yuyong Ma and Chuo Chen
Inorganic Chemistry Frontiers 2014 - vol. 1(Issue 5) pp:NaN472-472
Publication Date(Web):2014/03/25
DOI:10.1039/C4QO00057A
Vanadium(III) oxide catalyzes the direct fluorination of C(sp3)–H groups with Selectfluor. This reaction is operationally simple. The catalyst and the reaction by-product can be removed easily by filtration. Using this method, a fluorine atom can be introduced to the tertiary position of 1,4-cineole and L-menthone selectively.
Co-reporter:Ji-Bao Xia, Kevin W. Cormier and Chuo Chen
Chemical Science (2010-Present) 2012 - vol. 3(Issue 7) pp:NaN2245-2245
Publication Date(Web):2012/04/13
DOI:10.1039/C2SC20178J
Vanadium complexes have been used extensively to catalyze olefin and alcohol oxidation. However, their application in C–H oxidation has not been well-studied. We report herein that commercially available Cp2VCl2 catalyzes benzylic C–H oxidation selectively and effectively, giving no aromatic oxidation products.
![2-(2',3-DIMETHYL-2,4'-BIPYRIDIN-5-YL)-N-[5-(2-PYRAZINYL)-2-PYRIDINYL]ACETAMIDE](http://img.cochemist.com/ccimg/1243300/1243244-14-5.png)
![2-(2',3-DIMETHYL-2,4'-BIPYRIDIN-5-YL)-N-[5-(2-PYRAZINYL)-2-PYRIDINYL]ACETAMIDE](http://img.cochemist.com/ccimg/1243300/1243244-14-5_b.png)
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![4(1H)-Quinazolinone, 2-[4-(trifluoromethyl)phenyl]-](http://img.cochemist.com/ccimg/83900/83800-83-3_b.png)
![9,9'-[(2R,3R,3aS,7aR,9R,10R,10aS,14aR)-3,5,10,12-tetrahydroxy-5,12-dioxidooctahydro-2H,7H-difuro[3,2-d:3',2'-j][1,3,7,9,2,8]tetraoxadiphosphacyclododecine-2,9-diyl]bis(2-amino-3,9-dihydro-6H-purin-6-one)](http://img.cochemist.com/ccimg/61100/61093-23-0.png)
![9,9'-[(2R,3R,3aS,7aR,9R,10R,10aS,14aR)-3,5,10,12-tetrahydroxy-5,12-dioxidooctahydro-2H,7H-difuro[3,2-d:3',2'-j][1,3,7,9,2,8]tetraoxadiphosphacyclododecine-2,9-diyl]bis(2-amino-3,9-dihydro-6H-purin-6-one)](http://img.cochemist.com/ccimg/61100/61093-23-0_b.png)
![Tricyclo[3.3.1.13,7]decan-1-ol, 3-fluoro-](http://img.cochemist.com/ccimg/58700/58652-35-0.png)
![Tricyclo[3.3.1.13,7]decan-1-ol, 3-fluoro-](http://img.cochemist.com/ccimg/58700/58652-35-0_b.png)
![Benzeneacetonitrile, α-[(4-methoxyphenyl)amino]-](/data/chemimg/1189700/32323-74-3.png)
![Benzeneacetonitrile, α-[(4-methoxyphenyl)amino]-](/data/chemimg/1189700/32323-74-3_b.png)
![[5-(4-amino-2-oxopyrimidin-1-yl)-3,4-dihydroxyoxolan-2-yl]methyl [5-(6-aminopurin-9-yl)-4-hydroxy-2-(hydroxymethyl)oxolan-3-yl] Hydrogen Phosphate](http://img.cochemist.com/ccimg/4900/4833-63-0.png)
![[5-(4-amino-2-oxopyrimidin-1-yl)-3,4-dihydroxyoxolan-2-yl]methyl [5-(6-aminopurin-9-yl)-4-hydroxy-2-(hydroxymethyl)oxolan-3-yl] Hydrogen Phosphate](http://img.cochemist.com/ccimg/4900/4833-63-0_b.png)
![Tricyclo[3.3.1.13,7]decane-1-carboxylicacid, 3-fluoro-](http://img.cochemist.com/ccimg/900/880-50-2.png)
![Tricyclo[3.3.1.13,7]decane-1-carboxylicacid, 3-fluoro-](http://img.cochemist.com/ccimg/900/880-50-2_b.png)
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![1H-Tetrazole,5-[[2-[[(1,1-dimethylethyl)dimethylsilyl]oxy]ethyl]sulfonyl]-1-phenyl-](http://img.cochemist.com/ccimg/519100/519013-65-1_b.png)
