Structures Systems MACCS

ChemSketch is a software program developed in-house to draw chemical structures and to retrieve structures from MACCS. It is written in VAX C and will run on any of the VAX CPUs as long as they are running the VMS operating system. ChemSketch currently supports Tektronix 401x, VT-640, and VT-240 terminal emulation. 

In addition to the commonly used MACCS structural fragment keys (MDL Information Systems, Inc., San Leandro CA) and Daylight or UNITY fingerprints (Daylight... 

MACCS-II enables direct interface with other database management systems, such as the Relational Database Management System (RDBMS) and Oracle, so that databases which contain text and numeric data for which special interfaces are normally needed can be constructed. For example, an Oracle MACCS-II linked system is currendy being used by the National Institute on Dmg Abuse (113) to develop a database that will allow scientists to determine the molecular structures of cocaine and other controlled substances as well as designer dmgs. 

Stanley V. Kasparek, Computer Graphics and Chemical Structures Database Management Systems, CAS Registry, Chembase, REACCS, MACCS-II, Chemtalk, Wiley, New York, 1990. 

Figure 9.3. MACCS— the Molecular ACCess System—an early structure indexing system. This program originally used fixed menus for searching, registration, and reporting. Later versions allowed users to customize the menus. The figure shows the result of a 3D pharmacophore search for ACE inhibitors. Out of a database of 115,000 structures, 21 fit the 2D and 3D requirements of the search query. The user could typically browse the "hits" from the search, save the list of structures to a list file, and output the structures to a structure-data file (SDFile). The MACCS database was a proprietary flat database system in which data of a given type, say, formula, was stored in a given file, indexed by the compound ID number.

Several commercial providers of chemoinformatic tools have issued systems for calculating molecular fingerprints. Commonly used formats are those used in the molecular structure database systems developed by MDL (ISIS and MACCS) and the Daylight fingerprints. 

Two different MACCS keys (or MDL keys) [MACCS keys - MDL Information Systems Inc., 2008 Durant, Leland et al, 2002] are commonly encountered, one containing 960 bits and the other, which is public, containing a subset of 166 bits (ISIS keys). The fragment dictionary is based on a number of atom types, atom pairs, and custom atom environments. There can be a one-to-one relationship between the structural features and bits, or hashing can be used to create a many-to-one or many-to-many relationship between the features and bits. 

The total number of chemical compounds registered as their substrates, cofactors, and products are 842 on July 1988 and Increase with each update of the database. Chemical structures of these chemical compounds are stored with the related enzyme names on a MACCS system (Molecular Design Ltd) Installed on a FACOM-380 In the Institute for Chemical Research, Kyoto University. Few Inhibitors are registered now, because we have Just started collecting the chemical structures of the Inhibitors of the enzymes In this database. 

The chemical structure files built by these software packages consist of connection tables, a form of structural representation used in the CAS Chemical Registry System, and in consequence by both CAS ONLINE and DARC, and incidentally in many other systems (including MACCS). Both CPSS and PSIDOM include modules for building chemical structure data bases on personal computers which, in the case of PSIDOM, are limited only by the capacity of the disk storage... 

The next step up in integration places as much information as possible in the chemical structure or reaction DBMS. For example, Molecular Design Limited s MACCS system has been used to store structures, reactions, biology, spectra, inventory, and document index information. This approach provides a good degree of data integration but suffers from poor performance for large databases. Additionally, the retrieval capabilities of the structure DBMS are inadequate for certain types of information. 

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