Personal Experience with Four Kinds of Chemical St

Zhenjiang Li,*,†,‡Honggui Wan,†Yuhu Shi,†and Pingkai Ouyang†

College of Life Science and Pharmaceutical Engineering,Nanjing University of Technology, Nanjing210009,China,and College of Chemistry and Chemical Engineering,Xinjiang University,

Urumqi830008,China

Received June24,2004

1.BACKGROUND

Chemical structure drawing software is specialized in the chemical structural information with regards to processing, storing,rendering,and editing.With the advent of bioinfor-matics and chemoinformatics explosion,professional chemi-cal informatics software for personal computers developed rapidly.For the complexity and specialty of chemical information,to use general-purpose drawing software in chemical structure drawing was painstaking and inefficient. The result was unsatisfactory even in the case of simple molecular drawings.The expression of three-dimensional molecular structure and the conversion of molecular structure from two-dimensional to three-dimensional(2D to3D)were unfeasible by common graphic software.More than a dozen years ago,chemical professionals made use of ink-pen and chemical stencil sets to prepare papers or presentations.Free-hand chemical drawing was not uncommon in professional publications.Nowadays,people in chemistry get use to a variety of chemical drawing software in dozens-megabits size.The slim and compact software for chemical drawing of the DOS time seems to be a remote memory.If it was a rarity in the DOS time,the chemical drawing software is commonplace now.Chemists use it everyday.There are more than a dozen popular chemical drawing software,1such as ChemDraw,ChemWindow,ChemPen,C-Design,Chem-Frontier,DrawMol,and MolDraw,which belong to stand-alone ones,and ISIS/Draw,ChemSketch,and Chemistry4-D Draw,which work as interfacial software or add-ins. Interfacial software is usually a member of a suite and could be used independently.Powerful standalone software such as ChemDraw and ChemWindow are members of com-mercial suites.This article is based on the authors’experi-ences with ChemDraw,ChemWindow,ISIS/Draw,and ChemSketch;the current version of ours is5.0Ultra,6.0, 2.5,and5.12,respectively.

2.INTRODUCTION

ChemDraw,2ChemWindow,3ISIS/Draw,4and Chem-Sketch5are the most popular chemical drawing software in recent years.ChemDraw is the chemical drawing member of the well-known commercial chemical software suite ChemOffice.ChemWindow was first integrated into Bio-Rad Sadtler Suite and later into KnowItAll Analytical Systems after Bio-Rad Laboratories’merger of SoftShell. ISIS/Draw is the interfacial software to ISIS/Base database and a member of the MDL ISIS.ChemSketch is the interfacial software to and a member of the ACD/Labs.The fundamentals of the four kinds of software are listed in Table 1.

Of the four kinds of software,ChemDraw is a specialized chemical drawing software developed by CambridgeSoft. ChemWindow was a specialized chemical drawing software before version 6.0,and it is the interfacial software to KnowItAll Analytical Systems now.ISIS/Draw is designed by MDL Information Systems for its MDL ISIS bundle. ChemSketch is the interfacial graphic software for ACD/ Labs suite by Advanced Chemistry Development.As for the status of the software,ChemDraw was commercial from its first publication.A free copy of ChemWindow was available when it was under SoftShell,the situation changed,and no free ChemWindow is offered in the name of Bio-Rad Laboratories.To the dismay of many freebie lovers,Ad-vanced Chemistry Development declared that the free copy of the members of ACD/Labs suite is no longer provided in the6.0new version,but a free copy of the earlier5.0version is still available for the time being.The MDL’s ISIS/Draw is the only one of the four which keeps a free policy constantly.It may be the best choice for college students and light duty users.Recently,the academic edition of KnowItAll3.0is offered free by Bio-Rad Labs on the Web. It is good news for academic users.It should be mentioned that as the new edition of ISIS/Draw2.5was published,the 2.4edition disappeared on the MDL Web site,but the earlier

2.3copy is still available.

3.UTILIZATION

The situation of using a particular software is largely dependent upon the working requirement of the user.Take ChemOffice5.0Ultra as an example,the user’s manual for ChemDraw is222pages;the manual of Chem3D is244 pages.It will take a lot of time to read the manuals and try out the tutorial exercises.To master professional chemical drawing software like ChemDraw is not an easy task.Most users tend to be limited to the extent of their practical demand.They may be more familiar with several functions closely associated with their routine job but are not aware of some fundamental usages of other functions.We hope this article will be helpful to these common users.

*Corresponding author fax:+8625833254;e-mail:zj_lee@sohu.com.

Corresponding author address:No.21,Youhao Beilu Road,Urumqi

830008,China.

†Nanjing University of Technology.

‡Xinjiang University.

1886J.Chem.Inf.Comput.Sci.2004,44,1886-10

10.1021/ci049794h CCC:$27.50©2004American Chemical Society

Published on Web08/07/20043.1.Installation.The four kinds of software are easy to install.Except for ChemOffice,the other three come with setup options.ChemSketch and ISIS/Draw entered the optional function-modules window after the click of the installer,and the modules could be ticked.ChemWindow went to options of‘Typical’,‘Compact’,and‘Custom’.Full installation is recommended unless there is a hardware limitation.In addition to ACD/Labs,Advanced Chemistry Development provided free add-ins for ChemSketch and free add-ins to the third party software,which included Chem-Draw and ISIS/Draw.

3.2.Primary Chemical Drawing.The basic drawing tools

were laid out by the software’s presetting after entering the user’s interface.The window of ChemWindow looked most simple with only one standard tool-bar,but users could choose as many as12tool-bars in addition to a ruler and a status bar.ISIS/Draw and ChemDraw came with a concise interface.They were equipped with two fixed tool-bars and an optional ruler and grid.ISIS/Draw seemed more simple and pleasant to the eyes of the two.ChemSketch appeared a bit redundant at the first glance of its interface and was cumbersome to beginners.It seemed that all tools were stacked on the desktop but the grid.There are two interfaces that could be switched to and fro.The software preset one is‘Structure’and the other one is‘Draw’.Only a standard tool-bar and a drawing tool-bar are fixed in the switches. The basic drawing with the software is exemplified below.

3.2.1.Free-Hand Drawing of Chemical Structure. Drawing simple structures and reactions is often carried out freehand.In the drawing of complicated objects,freehand drawing is indispensable in the finishing and detail modifica-tion after templates are used.In the standard tool-bar,tools of bonds,atoms(or elements),chains,arrows,lines,curves, and polygons are most useful.The using of bond-tool of the software is illustrated in Figure1.Among the four,Chem-Draw and ChemWindow rank first in the number of types of bonds,and ChemSketch ranks last but with excellent function.ISIS/Draw is weak in this term.

3.2.2.Drawing with Templates and Presetting.The templates of ChemSketch are most powerful and user-friendly.ChemSketch and ChemDraw provide customer templates.The other two do not.The latter situations may be circumvented.In ISIS/Draw,templates should be prepared beforehand,saved in the‘Template’folder,and then imported to the new template by opening it in the‘Template Editor’.In ChemWindow,no template editing function is available;a customer template file may be saved in the ‘Template’folder,then opened in the‘Preference’dialogue box in the‘File’menu,and designated as the path of the customer template file.The size of the template file of ChemWindow is large.A wide variety of2000and3000 molecular structures are accommodated in two of the four templates.Some templates of the software are exemplified in Figure2.

To use a template in a drawing job is fundamental.Much effort should be made on the basis of dozens of templates. As illustrated in Figure3,in the retrosynthesis analysis7of taxol,templates of carbon rings,fused rings,aliphatic chains, groups,arrows,and reaction symbols were employed; functions of element,bond,lines,and caption were used.

Table1.Brief Summary and Comparison of the Four Kinds of Chemical Software

software ChemDraw5.0ChemWindow6.0ISIS/Draw2.5ChemSketch5.12

suite ChemOffice Bio-Rad Sadtler Suite MDL ISIS ACD/Labs

first publication/current version61985/8.019/7.01990/2.51994/7.0

minimum hard-disk required42.58Mb(suite)37.07Mb(suite)10.61Mb(standalone)17.01Mb(module) processor minimum Pentium Pentium X486Pentium300MHz

RAM recommended32Mb up32Mb up16Mb up32Mb up

software type commercial commercial free free(before v.6)

other add-ins/utilities NA/yes NA/yes NA/yes yes/yes

add-ins to third-party NA NA NA yes(to ChemOffice and MDL) plug-in service ChemDraw Plug-in BrowseIt ISIS/host ACD/I-Lab

3D graphics Chem3D SymApps RasMol3D

Viewer

Figure1.Available different bond types of the

software.

Figure2.Examples of templates from the

software.

Figure3.Retrosynthesis of taxol by Nicolaou’s group.

C OMPUTER S OFTWARE R EVIEWS J.Chem.Inf.Comput.Sci.,Vol.44,No.5,20041887Furthermore,operations of selection,move,duplicate,paste, rotate,reflection,flip,and alignment are indispensable. Several sets of publishing styles of frequently accessed academic chemical journals are preset in the software.The publishing format of the American Chemical Society is often used.ChemDraw adopted the1996format of the ACS

publishing materials as one of its preset styles.Other examples are the JOC(J.Org.Chem.)style in ChemWindow, the TETRA(Tetrahedron series)style in ISIS/Draw,and the JMolModl style in ChemSketch.The journal styles of the software are summarized in Table2.

3.2.3.Drawing of Glassware and Chemical Process Chart.All the software contains glassware templates except for ISIS/Draw.ChemWindow contains139sets of glassware, which is most powerful,user-friendly,and can be au-todocked.ChemSketch was featured with200kinds of glassware.They are clearly prepared and standard sized,can be autodocked,and are convenient to users.ChemDraw has a few sets of glassware.A chemical process template is unique to ChemWindow,which contains97sets of templates for chemical equipments and units drawing.Lab equipments and a chemical process are drawn and exemplified in Figures 4and5.

3.3.Intermediate Usage.In the four kinds of software, ISIS/Draw is the most concise.ChemWindow and Chem-Sketch are comparable in complexity.The latter is more powerful in function.ChemDraw is the most comprehensive and powerful one.To master ISIS/Draw is not an easy task, and the others are more demanding.For software such as ChemDraw,both insight into computer software and an understanding of professional chemistry is essential to effectively use it.A variety of skills in manipulating chemical information on a computer is required for an intermediate user.Frequently encountered tasks include user’s templates, interconversion of different file formats,input and output of files through different formats,from structure to nomen-clature and from character string to structure,2D to3D conversion,3D structure optimization,molecular property calculation and prediction,management of analytical spectra, database management,online service,and so on.

3.3.1.Structure and Nomenclature.From structure to name is the most frequently used function.All four kinds of software supply nomenclature modules except for Chem-Window.8Beilstein’s AutoNom is integrated into Chem-Draw.ChemSketch uses its own ACD/Name,which supports ChemDraw and ISIS/Draw as an add-in.Besides ACD/ Name,ISIS/Draw uses AutoNom as add-in,but the free ACD/Name is not capable of naming a structure with more than3rings.An alkaloid sparteine and a terpene cedrane were illustrated in Figure6.Nomenclature by two of the software resulted as follows:cedrane by ACD/Name is (1R,2R,5S,7R,8R)-2,6,6,8-tetramethyltricyclo[5.3.1.0-1,5-] undecan,by AutoNom is(3R,8aS,9R)-3,8,8-trimethyl-6-(R)-methyl-octahydro-3a,7-methano-azulene;sparteine by Au-toNom is(7S,7aR,14S,14aS)-dodecahyro-7,14-methano-dipyrido[1,2-a;1′,2′-e][1,5]diazocine.

The function of name-to-structure is only available in ChemDraw.The free edition of ChemSketch has the function

Table2.Functional Features of the Four Kinds of Chemical Software

software ChemDraw5.0ChemWindow6.0ISIS/Draw2.5ChemSketch5.12 journal style settings8696

latest files NA4910

bond types91486

arrows41113067

templates/user’s set12/yes6/yes23/yes42/yes glassware yes yes NA yes

structure to name yes(AutoNom and ACD/Name)NA yes(AutoNom and ACD/Name)yes(ACD/Name) name to structure yes NA NA yes(from SMILES) Nick Name yes yes NA yes(standalone) clean structure yes yes yes yes

2D to3D yes(standalone)yes(add-in)yes(add-ins)yes(add-in)

prediction of properties yes NA NA

yes

Figure4.Lab experimental

glassware.

Figure5.A chemical separation

process.

Figure6.Nomenclatures by different software.

1888J.Chem.Inf.Comput.Sci.,Vol.44,No.5,2004C OMPUTER S OFTWARE R EVIEWSof generating structure from SMILES(Simplified Molecular Input Line Entry Specification).A few average users command the SMILES and the function appeared not popular.ChemSketch can produce SMILES from structure, which may be helpful to learners of SMILES.

An important function connected with structure and nomenclature is‘User’s accustomed name’,which designates a specific compound or functional group to a specific string. After inputting a character string,the software will recognize it as a legible structure.The feature is termed‘Nick Name’in ChemDraw,‘User’s Chemistry’in ChemWindow,and ‘Label’in ChemSketch.ChemDraw is powerful in‘Nick Name’.In addition to the preset‘Nick Name’,the user may produce and edit his particular‘Nick Name’.A similar usage is to input a formula and obtain a structure.In ChemDraw, a formula such as‘CH3CH2CHCHCCCH3’may be input, recognized,and transformed into a2D structure.As for ChemWindow and ChemSketch,a string may only be added to a2D structure as a side-chain or a functional group. ChemWindow cannot recognize a string as a structure. ChemSketch takes a string as a‘Label’,in which a box pops up and strings such as‘C2H5’,‘COOEt’,and‘PO3H2’may be chosen.The‘Label’can be edited and customized.

3.3.2.Three-Dimensional Structure.All four kinds of software are equipped with a three-dimensional structure rendering function.ISIS/Draw integrates RasMol as its3D viewer.ACD provides a free ACD/3D Viewer to ISIS/Draw as an add-in.The other three designed their own3D rendering software.ChemSketch uses a ACD/3D Viewer. Chem3D is a member of the ChemOffice suite.A structure made by ChemDraw may be pasted on or exported to Chem3D,rendered in3D,and calculated in properties. ChemWindow employs its bundled SymApps to display a 3D structure and make calculations.ISIS/Draw and Chem-Sketch are comparable in molecular3D processing ability. ChemSketch can make a structural optimization,and ISIS/ Draw can do the same job after installation of a ACD/3D Viewer add-in.ISIS/Draw integrates RasMol as its default 3D viewer,which cannot make3D optimization,so a ACD/ 3D Viewer is preferred.Except for Chem3D,the other3D software is integrated into the structure drawing software, such that a2D drawing may be rendered in3D instantly. The ACD/3D Viewer is the most convenient to the average user.SymApps is powerful in3D calculation.Chem3D is semiprofessional3D calculation software.It is popular in educational application.The integrated quantum mechanics engines and molecular mechanics engines are fairly powerful. Professional molecular calculations can be carried out.We tried a conformational optimization of a nonapeptide on a PC with1G CPU,which took a few dozen minutes.

3.3.3.Management of Spectral Information.Three of the four kinds of chemical drawing software are capable of spectra management.ISIS/Draw cannot process spectral information.ChemWindow and ChemSketch need member software in their respective suite to manipulate spectra. ChemDraw supports the JCAMP format(*.jdx file)and the Galactic format(*.spc file).The spectra may be moved and rescaled in the window of ChemDraw.The ACD/SpecViewer is more powerful and popular,which supports JCAMP(*.jdx, *.dx,*.jxs,*.jx),Galatic(*.spc),ASC II(*.txt),and ACD (*.esp)formats.

3.3.

4.Other Usages.ChemDraw supports many formats in the file input and output operations.The other three support a few.File format conversion is a frequent task.A piece of free software‘Mol2Mol’is useful in3D file interconversion.It supports most3D file type and several 2D file formats.For the interconversions between2D format files,free‘2DConverter’from CambridgeSoft may be employed.In addition to the interconversion among formats of.cdx,.chm,.f1d,.f2d,.rxn,.skc,.tgf,.smd,.jdx,.mol, .msm,and.wmf,it supports a2D molecular structure file with no extension to be converted into the above-mentioned formats.

Online services are getting more popular.In fact,ISIS/ Draw is interfacial software for chemical database service. Besides working as a2D molecular structure interface for MDL ISIS,it is integrated into CrossFire of Beilstein.ACD/ Labs uses I-Lab to connect to its net server.The famous ‘chemweb’uses ISIS/Draw as graphic interface in online search,and more than a dozen online databases at chemweb worked in this way.It provides online a free ACD/Labs Name-to-Structure service and displays a2D structure with ISIS/Draw Plug-in and a3D structure with Chime Plug-in. The online‘Organic Syntheses’incorporates ChemOffice Plug-in as input and display interface.

The software provides calculation functions for various molecular properties.Molecular weight and composition can be calculated.Density and thermodynamic data can be predicted.Spectral data can be simulated.ACD offers ChemBasic as an add-in to ChemSketch,which support customer programming based on ChemSketch.In addition, ChemBasic provides22Goodies for the functional expansion to ChemSketch.As a summary,comparison of the functions of the software is listed in Table2.

Table3.Personal Experiences with the Four Kinds of Chemical Software a

software ChemDraw5.0ChemWindow6.0ISIS/Draw2.5ChemSketch5.12 2D drawing excellent good excellent excellent 3D excellent good average good

lab average excellent NA good

spectra average average NA excellent online excellent NA excellent excellent user’s programming NA NA NA yes

files’formats supporting excellent average average average

comprehensive good average average excellent overall excellent good good excellent

a CS ChemDraw is the trademark of CambridgeSoft Corporation.ChemWindow is the trademark of Bio-Rad Corporation.ISIS/Draw is the trademark of MDL Information Systems,Inc.ACD/ChemSketch is the trademark of Advanced Chemistry Development,Inc.

C OMPUTER S OFTWARE R EVIEWS J.Chem.Inf.Comput.Sci.,Vol.44,No.5,2004184.CONCLUSION

All four kinds of chemical drawing software can do a2D drawing job well.The progress of ChemSketch is remarkable in comprehensive performance improvement and intelligent module development.It makes for the integration of3D, spectral processing,spectral calculation,physical chemical properties’prediction,and online service,which represent the mainstream technical trend in chemical drawing software. ChemDraw as a traditional drawing software is most power-ful in drawing,but the3D function is not integrated,and the spectral functions need to be improved.The compre-hensive performance of ChemWindow is greatly enhanced after its integration into KnowItAll.In addition to its features in a lab apparatus module and a chemical engineering process module,the spectral information processing function is outstanding due to its merger with Bio-Rad.Generally speaking,ChemWindow and ChemSketch are comparable in overall performance.ISIS/Draw is pure chemical drawing software.There is no sign of developing it into comprehen-sive chemical structure software in the most recent2.5 edition.The impressive feature of ISIS/Draw is simple.To make an evaluation1,9on chemical drawing software is not an easy task.The preference of professional software is mainly dependent upon the user’s objective.So it seems improbable to make an extensively acceptable recommenda-tion.For users focused on2D drawing,ISIS/Draw is the first choice.ChemDraw plus Chem3D is undoubtedly best for3D professional users.ChemSketch meets extensive task duty requirements in drawing,3D,spectral information, physical chemical properties,and customer programming. ChemWindow can facilitate users who span chemistry lab and engineering process design.The evaluation and com-ments are listed in Table3for reference.A detailed illustration on individual software may be acquired at the respective Web sites.2-5,10

REFERENCES AND NOTES

(1)http://www.chemweb.com/alchem/articles/1035208669995.html.

(2)ChemDraw,CambridgeSoft Corporation,875Massachusetts Ave.,

Cambridge,MA02139,USA.Visit http://www.camsoft.com/for further information.

(3)ChemWindow,Bio-Rad Laboratories,Sadtler,3316Spring Garden

Str.,Philadelphia,PA19104.Visit http://www.chemwindow.com/and preferably at http://www.informatics.bio-rad.com/for further informa-tion.

(4)ISIS/Draw,MDL Information System,14600Catalina Street,San

Leandro,CA94677,USA.The program(editions of2.5and2.3)is available at the MDL at http://www.mdli.com/.

(5)ChemSketch,Advanced Chemistry Development Inc,Toronto,Canada.

The program(edition 5.x)is available at the ACD at http:// www.acdlabs.com/.

(6)Buntrock,R.E.ChemOffice Ultra7.0.J.Chem.Inf.Comput.Sci.

2002,42(6),1505-1506.

(7)Nicolaou,K.C.;Vourloumis,D.;Winssinger,N.;Baran,P.S.The

Art and Science of Total Synthesis at the Dawn of the Twenty-First Century.Angew.Chem.,Int.Ed.2000,39,44-122.

(8)The successor of ChemWindow,KnowItAll3.0,which contains the

‘IUPAC NameIt’module,is powerful in structure-to-name and name-to-structure functions.

(9)Gunda,T. E.At http://dragon.klte.hu/∼gundat/rajzprogramok/

dprog2.html.A previous version of this document can be found in a reshaped article form at Internet J.Chem.2000,3,L25.http:// www.ijc.com/articles/library/25.

(10)(a)Chemistry4-D Draw:ChemInnovation Software,Inc.Internet

address at http://www.cheminno V ation.com/.(b)ChemPen for Win-dows,by Evans,H.,and Internet address at http://www.chempensoft-ware.com/chempen.htm.(c)C-Design for Windows(interface in German),Internet address at http://www.chemie.tu-muenchen.de/oc1/ EFontain/C-Design/.(d)ChemFrontier for Windows,from Fujitsu Ltd., Internet address at http://www.fqspl.com.pl/chemfrontier/.(e)MolDraw for Windows,by Ugliengo,P.;Viterbo,D.;Chiari,G.Internet address at http://www.ch.unito.it/ifm/fisica/moldraw/a V ail.html.(f)DrawMol for Windows,Internet address at http://www.compuchem.com/.

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