MACCS

The definitions of MDL s 166 MACCS search keys can be found in the ISIS/ Base help file, section 49.2.4 Specifying searchable keys as a query. 

MACCS/ISIS Databases and DB management systems Daylight Chemical Infor-mation Systems Molecular Design Limited, Inc. (MDLI)... 

MDL Information Systems, Inc. MDL provides modular software systems for managing chemical information, as weU as related molecular and reaction databases for use with the software. MDL s database management programs, MACCS-II and REACCS, provide access to compound and reaction databases and also have the capabiHty to manage user-created databases (37). Although MDL is not considered to be an on-line database vendor, it is mentioned here because of the value of its information products and services to the chemical industry. 

Nuclear Magnetic Resonance Spectroscopy. Bmker s database, designed for use with its spectrophotometers, contains 20,000 C-nmr and H-nmr, as weU as a combined nmr-ms database (66). Sadder Laboratories markets a PC-based system that can search its coUection of 30,000 C-nmr spectra by substmcture as weU as by peak assignments and by fiiU spectmm (64). Other databases include one by Varian and a CD-ROM system containing polymer spectra produced by Tsukuba University, Japan. CSEARCH, a system developed at the University of Vieima by Robien, searches a database of almost 16,000 C-nmr. Molecular Design Limited (MDL) has adapted the Robien database to be searched in the MACCS and ISIS graphical display and search environment (63). Projects are under way to link the MDL system with the Sadder Hbrary and its unique search capabiHties. 

University of Vienna 13/ C-nmr 16,000 PPC-based CSEARCH MACCS, ISIS searchable... 

The following chemical databases are available for searching in MACCS-II. ChemicalDirectoy Database contains a combined catalogue of 66 commercial suppHers of more than 77,000 organic chemicals. AL4.CCS-II Drug Data eport based on the Prous Dmg Data Report, includes 39,000 compounds with information on therapeutic indication, biological action, phase of development, related patents, and Hterature references. MUSE Database the tutorial database for MACCS-II, contains over 100 compounds. 

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 constmcted. Eor 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 stmctures of cocaine and other controlled substances as well as designer dmgs. 

MACC was established in 1967 and encompasses nearly 50,000 square miles from Virginia to New York. MAAC contains the PJM centrally dispatched electric control area, which is the largest such area in North America and the third largest in the world. PJM Interconnection became the first operational independent system operator in the United States on Januai y 1, 1998. 

Clearly, within the conceptual framework described above, there is extensive room for exploration in creating fingerprints and similarity measures to retrieve molecules based on varying conceptions of similarity [42—441. The simplest types of fingerprint consist simply of features indices that map the presence or absence of a small library of functional groups. The most well known and effective are the MACCS keys. These were initially chemical feature indices, that we later used successfully as a similarity metric. 

The authors would like to acknowledge the contributions of the following researchers J.R. DeBaun and L.S. Mullen-Rokita, for helpful discussions E.B. Cramer, for assisting with the adsorption measurements L.-S. Yu-Farina, for the water solubility and partition coefficient measurements H. Myers, for the vapor pressure measurements and R.R. Winter, for running the MACCS molecular structure analyses. 

As illustrated in the next section, the use of biological fingerprints, such as from a BioPrint profile, provides a way to characterize, differentiate and cluster compounds that is more relevant in terms ofthe biological activity of the compounds. The data also show that different in silico descriptors based on the chemical structure can produce quite different results. Thus, the selection of the in silico descriptor to be used, which can range from structural fragments (e.g. MACCS keys), through structural motifs (Daylight keys) to pharmacophore/shape keys (based on both the 2D structure via connectivity and from actual 3D conformations), is very important and some form of validation for the problem at hand should be performed. 

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

In order to obtain the solution desired, a value of Ts is assumed, the vapor pressure of A is determined from tables, and mAs is calculated from Eq. (6.98). This value of mAs and the assumed value of Ts are inserted in Eq. (6.97). If this equation is satisfied, the correct Ts is chosen. If not, one must reiterate. When the correct value of Ts and mAs are found, BT or BM are determined for the given initial conditions Tx or mAco. For fuel combustion problems, mAcc is usually zero however, for evaporation, say of water, there is humidity in the atmosphere and this humidity must be represented as mAco. Once BT and BM are determined, the mass evaporation rate is determined from Eq. (6.87) for a fixed droplet size. It is, of course, much preferable to know the evaporation coefficient (5 from which the total evaporation time can be determined. Once B is known, the evaporation coefficient can be determined readily, as will be shown later. 

D. MACCS-3D a new database system for three-dimensional molecular models. Chem. Inf. Syst. 1990, 42-49. 

Guner, O.F., Hughes, D.W., and Dumont, L.M. An integrated approach to three-dimensional information management with MACCS-3D./. Chem. Inf Comput. Sci. 1991, 31, 408-414. 

Maccabees mentions the silver and gold mines of Spain (I Macc. 8, 1-3). 

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