CHEM 767 FINAL EXAM ANSWER KEY

Chemistry 767
Chemical Information Retrieval
Summer 1995

Final Examination ANSWER KEY
September 5, 1995

You are to do this examination by yourself in three hours, utilizing whatever on-line resources or Hagerty Library resources you need. You are not to confer with anyone else in the course about this examination, while you are doing it or for several days afterwards (note that all students are not taking the exam on September 5). You must hand in this examination paper with answers to the questions given below. You should also hand in a file on disk or a print-out of that file to support your answers wi th data. Your exam will be graded on the basis of the correctness and completeness of your answers and the quality of the data which you have gathered to corroborate the answers. Late exams will not be accepted.

Problem statement:

The use of combinatorial methods in chemistry, also known as "combinatorial chemistry," has undergone a recent strong growth in interest and in publication activity. The purpose of this 3-hour project is to collect bibliographic data which support this a ssertion, and to prove to you that in three hours you can learn a good deal about this field and why it has mushroomed!

1. What related terms are used in Chemical Abstracts to index combinatorial applications in chemistry?
E2 1 COMBINATOR
E3 607* COMBINATORIAL
E4 213 COMBINATORIAL LIBRARY
E5 1COMBINATORIALLY
E6 7 COMBINATORIC
E7 3 COMBINATORICAL
E8 34 COMBINATORICS
E9 17 COMBINATORY
2. How many publications in combinatorial chemistry and related areas are abstracted in Chemical Abstracts? Break down your answer into 5-year intervals starting in 1970 and going through 1995.
S1 638 "COMBINATORIAL" OR "COMBINATORIAL LIBRARY" OR
"COMBINATORIALLY" OR "COMBINATORIC" OR
"COMBINATORICAL" OR "COMBINATORICS"
By searching S1 and PY=1966, 1967, etc. the following statistics can be developed:
1966-1970: 11 records
1971-1975: 17 records
1976-1980: 37 records
1981-1985: 48 records
1986-1990: 71 records
1991 on: 454 records (31 in 1991, 49 in 1992, 93 in 1993, 173 in 1994, and 108 so far in 1995)
3. In what subject areas within chemistry have publications on combinatorial chemistry occurred? [Hint: look at Section Codes] Look at all time periods, not just the recent years.
Display records with the suffix /SC to get this list; this is incomplete, and focuses only on recent records.
CA201004 Pharmacology
CA265008 General Physical Chemistry
CA234003 Amino Acids, Peptides, and Proteins
CA222XXX Physical Organic Chemistry
CA280XXX Organic Analytical Chemistry
CA221003 General Organic Chemistry
CA277XXX Magnetic Phenomena
CA225000 Benzene, Its Derivatives, and Condensed Benzenoid Compounds
CA235XXX Chemistry of Synthetic High Polymers
CA206XXX General Biochemistry
CA233XXX Carbohydrates
CA215XXX Immunochemistry
CA209009 Biochemical Methods
CA203XXX Biochemical Genetics
4. How many conference proceedings on combinatorial chemistry have been published in the past 5 years? From the search below, 1+5+14+18+1=39 books or conference proceedings were published on combinatorial aspects of chemistry from 1991-1995.
S26 31 S1 AND PY=1991
S27 49 S1 AND PY=1992
S28 93 S1 AND PY=1993
S29 173 S1 AND PY=1994
S30 108 S1 AND PY=1995
S31 722211 DT="BOOK" OR DT="CONFERENCE PROCEEDING"
S33 1 S26 AND S31
S34 5 S27 AND S31
S35 14 S28 AND S31
S36 18 S29 AND S31
S37 1 S30 AND S31
Display the titles, editors, and publication years of these proceedings. For set 33 (for example), use T33/ti,au/py/all to display this information.
5. Have there been any books published on combinatorial chemistry during the same period? If so, give the complete CA record for each.
S38 1 (S33 OR S34 OR S35 OR S36 OR S37) AND DT=BOOK
There has been one book published: 

        38/5/1


        DIALOG(R)File 399: CA SEARCH(R)

        (c) 1995 American Chemical Society.  All rts. reserv.

        123041350     CA: 123(4):41350r  BOOK

        The Theory and Practice of Combinatorial Chemistry.  (In: Perspect. Drug

        Discovery Des., 1995; 2 (2)

        AUTHOR(S): Houghten, Richard A.; Editor

        LOCATION: Neth.

        DATE: 1995  PAGES: 75 PP.  CODEN: BOOKA7  LANGUAGE: English

        PUBLISHER:  (ESCOM, Leiden, Neth.)

        SECTION:  CA265008  General Physical Chemistry

        IDENTIFIERS: book  combinatorial chem

        DESCRIPTORS:   Chemistry...

                                        the theory and practice of combinatorial chem.
6. How many reviews on combinatorial chemistry have been published in the 1994-1995 period? List the titles and authors of each of these reviews. 

        S41     70      S25 AND REVIEW
7. From the information that you have gathered so far, attempt a definition of the subject, "combinatorial chemistry," and indicate the year of the upsurge in interest in this field.

The definition of combinatorial chemistry can be inferred from the title of the articles and reviews and from the index terms used to describe the records found thus far, even though no abstracts are available in CA SEARCH on DIALOG. Of course, by using SciSearch, you have access to the abstracts of modern articles and can do a more precise job of defining this field. In the early years of Chemical Abstracts on-line, combinatorial methods of mathematics were used on many different chemical problems in a ll areas of chemistry. Modern combinatorial chemistry is the simultaneous use of large sets of chemically similar reagents (such as amino acids or carbohydrates) in binary chemical reactions to produce thousands of products which are then screened for bi ological activity or specific chemical properties. Publications in combinatorial chemistry have mushroomed in the past few years as the pharmaceutical potential of these synthetic/screening methods has become evident.

8. What is the earliest publication referring to the term "combinatorial library"? How many references are there to this term? How much overlap is there between this reference list and that of the more general subject with which you are dealing? I did this question using SciSearch, but using CA SEARCH would be OK also. 

        ?s combinatorial(n)chemistry
        S7      805     COMBINATORIAL(N)LIBRAR?

        ?s s7 and py=1992       
                        805     S7
                        720444  PY=1992
                S8       16     S7 AND PY=1992

        ?s s7 and py=1991
                        805     S7
                        706089  PY=1991
                S9          7   S7 AND PY=1991

        ?s s7 and py=1990
                        805     S7
                        686428  PY=1991
                S10         1   S7 AND PY=1990

Thus, the term "combinatorial library" or "combinatorial libraries" occurred first in 1990. Here is the SciSearch record: 

FN-     DIALOG(R)File 434: SciSearch(R)|
CZ-     (c) 1995 Inst for Sci Info.   All rts. reserv.|
AN-     10041760|
GA-     CW342|
TI-     *COMBINATORIAL**LIBRARIES* - A FAST NEW TRACK TO
        MONOCLONALS|
LA-     ENGLISH
AU-     LEWIS R|
CS-     SUNY ALBANY, BIOL/ALBANY/NY/12222|
GL-     USA|
JN-     SCIENTIST *1990*, V4, N7, P29|
PY-     1990|
DT-     ARTICLE|
NR-     O|
SF-     SciSearch; SciSearch; CC PHYS--Current Contents, Physical Chemical &
Earth Sciences; CC LIFE--Current Contents, Life Sciences; CC AGRI--Current 
Contents, Agriculture, Biology & Environmental Sciences; CC CLIN--Current 
Contents, Clinical Medicine; CC ARTS--Current Contents, Arts & Humanities; 
CC ENGI--Current Contents, Engineering, Technology & Applied Sciences; CC 
SOCS-Current Contents, Social & Behavioral Sciences|
SC-MULTIDISCIPLINARY SCIENCES|

9. How does the indexing of this subject area in SciSearch differ from its indexing in Chemical Abstracts?
Here I was looking for your realization that SciSearch covers all scientific fields, whereas Chemical Abstracts deals only with chemistry and related chemical fields.
In general, more of the early records in SciSearch which deal with combinatorial libraries or even combinatorial chemistry are from biological or medical publications.

10. One widely cited author in the area of combinatorial chemistry is R. A. Houghten. Find out what you can about his career, his present affiliation, and his publications in combinatorial chemistry. How many times are publications by Houghten ci ted? 

        S16             1386    CA="HOUGHTEN RA"
        S17               127   S16 AND PY=1990
        S18                 37  S16 AND S5
        S19               107   S16 AND S1
        S20               188   AU="HOUGHTEN RA"
From these searches, we see that RA Houghten has 188 records in SciSearch, and is cited 1386 times. Here is the abstract from a very recent review which cites RA Houghton. This abstract contains a good definition of combinatorial chemistry.
DIALOG(R)File434:(c) 1995 Inst for Sci Info. All rts. Reserv.
Abstract: The synthesis of large numbers of peptides can be very labor intensive and, if a conventional peptide synthesizer is used, only small numbers of peptides can be produced within a reasonable time. The techniques described below can make large numbers of different peptides simultaneously with varying degrees of mechanization, ranging from the wholly manual methods, to those involving complete mechanization of the whole synthesis process. Most of the multiple synthesis methods are primarily intended for small scale production ranging from microgram amounts up to a few tens of milligrams. All of the systems are economical in use of solvents and reagents, enabling cost-effective synthesis. The techniques described can also be used to prepare peptide libraries, containing several millions of peptide sequences, to enable the rapid screening of all possible permutations of amino acids within short peptides. However, it is considered that multiple synthesis methods are not particularly suited where extreme high purity or very long peptides are required.

11. In the field of combinatorial libraries there is a widely cited article in which Houghten is the first author. Find this article, print out its full record (including the abstract), and determine the number of times it has been subsequently cited. 

        E6              197     CR=HOUGHTEN RA, 1991, V354, P84, NATURE
        S20             188     AU="HOUGHTEN RA"
        S30                 7   S20 AND JN=NATURE
        S31                 1   S30 AND PY=1991
Here is the abstract of this article:
31/AB/1
DIALOG(R)File434:(c) 1995 Inst for Sci Info. All rts. reserv.
Abstract: EXISTING methods for the synthesis and screening of large numbers of peptides are limited by their inability to generate and screen the requisite number (millions) of individual peptides 1-4 and/or their inability to generate unmodified free peptides in quantities able to interact in solution 4-8. We have circumvented these limitations by developing synthetic peptide combinatorial libraries composed of mixtures of free peptides in quantities which can be used directly in virtually all existing assay systems. The screening of these heterogeneous libraries, along with an iterative selection and synthesis process, permits the systematic identification of optimal peptide ligands. Starting with a library composed of more than 34 million hexa-peptides, we present here the precise identification of an antigenic determinant recognized by a monoclonal antibody as well as the straightforward development of new potent antimicrobial peptides.

12. Determine the number of reviews which cited the article in question 11. After reading the abstracts of these reviews, write a paragraph explaining what a combinatorial library is, and what applications it has in chemistry. 

        S32     197     CR="HOUGHTEN RA, 1991, V354, P84, NATURE"
        S33       22    S32 AND DT=REVIEW
I was looking for a paragraph which is consistent with the abstracts displayed above.

Return to Chemical Information Courses Page
Return to Teaching Chemical Information

Last Modified: July 02, 1999
© Stanford University Libraries/Academic Information Resources