Status of Notation and Topological Systems and Potential Future Trends

Rush, James E.

doi:10.1021/ci60008a004

Cited by 12 publications

(7 citation statements)

References 15 publications

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“…Thus, H-LISTt means that SMF, contains no homologous series, H-LIST2 means that SMF2 contains a homologous series H, (alkyl [1][2][3][4]), and H-LIST3 means that SMF3 contains three homologous series H,, H2 (alkoxy[l-6]), and H3 (cycloalkyl [3][4][5][6]). GUC has the same format as H-LIST except for the prefixed field indicating the relevant constant part.…”

Section: File Organizationmentioning

confidence: 99%

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Computer representation of generic chemical structures by an extended block-cutpoint tree

Nakayama¹,

Fujiwara²

1983

J. Chem. Inf. Comput. Sci.

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effectiveness. Did we address the right problem? Did the information packet cause any different action on the part of the recipient? Was the information even used in subsequent action steps by the recipient? What was the ultimate value of the decision to which the information contributed? Was its contribution to the decision substantive or supportive? Was it filed away for possible future use or tossed into the round file?We first have to do the right thing and then learn to do it well. Packets of information (large or small), even delivered on time in neat array, with great eye appeal, have no value unless they are used to solve problems or support productive decisions. Hence, we do need an integrated approach with our users. We need candid feedback regarding the usefulness (value if you will) of the data/information/knowledge transferred. SUMMARYAn overview of the environment (from my perspective) related to information resource management in pharmaceutical R&D has been presented. Some notions of organizational preference (functional), employee selection (chemist turned information scientist), automation (user friendly, cost effective), and the value of project teams (information transfer) have been noted. Difficulties associated with keeping our innovative tools sharp were observed. Finally, we noted that our bottom line-productivity-should first consider what is useful (effectiveness) and then learn how to do it wellefficiency. Success in the management of information resources depends on the proactive delivery of information packets which find their way into problem solving and decision support for scientists or line managers.A representation scheme for generic chemical structures (Markush formulas) is presented. This method is an extension of a BCT (block-cutpoint tree) representation for specific chemical structures, and is called an EBCT (extended BCT) representation of generic chemical structures. A general Markush formula is dissolved into several simple Markush formulas by expanding conditions and nested substitutions. Variable parts of simple Markush formulas are represented in terms of a simple type of substituent group called a generic unit. An inverted file for homologous series and a fragment screening facilitate (sub)structure searches. INTRODUCTIONOne of the important problems in dealing with chemical structure information by computers is how to implement the representation of chemical structures in computer storage. So far, many representation methods have been proposed and implemented for specific chemical structures.' Those methods are categorized to two major approaches: the linear representation and the topological representation. One major reason why so many representation methods have been and will be devised is that we do not have such a complete representation method yet to support various types of substructure searches.

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Section: File Organizationmentioning

confidence: 99%

“…,cycloalkyl[3][4][5][6]} R4 = {H,alokxy[1][2][3][4][5][6]} R7 = {alkyl[1-4]} LISTy) in Figure10denotes a generic unit, say Sy.…”

mentioning

confidence: 99%

Computer representation of generic chemical structures by an extended block-cutpoint tree

Nakayama¹,

Fujiwara²

1983

J. Chem. Inf. Comput. Sci.

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“…By the above theorem, the number of permutations to be generated for perception of bond-atom symmetry is greatly reduced, and we need to construct only, 1 + ¿(|0,| - 1) permutations. For instance, the bond-atom symmetry of the By the equivalence of nodes perceived during the permutation generation, the construction of the first 12 permutations is sufficient for the determination of the orbit graph.…”

Section: Mathematical Treatmentmentioning

confidence: 99%

Algorithms for unique and unambiguous coding and symmetry perception of molecular structure diagrams. 5. Unique coding by the method of orbit graphs

Uchino¹

1982

J. Chem. Inf. Comput. Sci.

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“…By theorem II, there is one-to-one correspondence between the right coset of G(B) G(a) in G(s) and the normalized bond matrix. And hence, we can write the set S of (5) as:…”

Section: Fundamental Theorems Of Unique Coding and Symmetry Perceptionmentioning

confidence: 99%

Algorithms for Unique and Unambiguous Coding and Symmetry Perception of Molecular Structure Diagram. III. Method of Subregion Analysis for Unique Coding and Symmetry Perception

Uchino¹

1980

J. Chem. Inf. Comput. Sci.

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A procedure for unique and unambiguous coding of a chemical graph is described on a group theoretical basis. During the procedure, a chemical graph is transformed to a smaller graph by t'he use of logical atoms, and the invariant vector under the bond symmetry group of the derived graph is computed. The invariant vector is used to define the normalized representation from which a unique code is generated together with the associated symmetry group. A new efficient method was devised for the generation of the permutation vectors and is implemented by an extremely compact APL program.

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Status of Notation and Topological Systems and Potential Future Trends

Cited by 12 publications

References 15 publications

Computer representation of generic chemical structures by an extended block-cutpoint tree

Computer representation of generic chemical structures by an extended block-cutpoint tree

Algorithms for unique and unambiguous coding and symmetry perception of molecular structure diagrams. 5. Unique coding by the method of orbit graphs

Algorithms for Unique and Unambiguous Coding and Symmetry Perception of Molecular Structure Diagram. III. Method of Subregion Analysis for Unique Coding and Symmetry Perception

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