ROSDAL system

In this section the syntax which underlies the ROSDAL structure notation will be outlined. The ROSDAL system also provides for a flexible description of different kinds of substructures however, the main emphasis will be given to the... 

The SDF format has a flexibility similar to that of the ROSDAL system and is capable of storing every inorganic compound with or without a structure, single or multicomponent, and with more than one component. It repre.sents a... 

The ROSDAL (Representation of Organic Structures Description Arranged Linearly) syntax was developed by S. Welford, J. Barnard, and M.F. Lynch in 1985 for the Beilstein Institute. This line notation was intended to transmit structural information between the user and the Beilstein DIALOG system (Beilstein-Ohlme) during database retrieval queries and structure displays. This exchange of structure information by the ROSDAL ASCII character string is very fast. 

ROSDAL is used in the Beilstein-DIALOG system [17] as a data exchange format. The code can represent not only full structures and substructures but also some generic structures. 

J.M. Barnard, C.J. Jochum, S.M. Wel-ford, ROSDAL A universal structure/ substmcture representation for PC-host communication, in Chemical Structure Information Systems Interfaces Communication and Standards, WA. Warr (Ed.), ACS Symposium Series No. 400, American Chemical Sodety, Washington, DC, 1989, pp. 76- 81. 

ROSDAL. Linear notation scheme devised by the Beilstein Institute. It can contain just connection table information, or it may also contain atom coordinates. Several chemical information systems can convert ROSDAL strings to other structure file formats. 

Key to the implementation of the substructure searching system is a chemical structure representation known as the ROSDAL string. This is an ASCII character string that conveys sufficient information to convey fully a structure representation, including stereochemistry. A subset of a structure, that is to say, a substructure query, can also be represented by the ROSDAL string. Use of the ROSDAL string provides two immediate advantages for any new substructure... 

QS QS The basic structure/substructure search command. It is entered before the ROSDAL string (linear representation of the structure) is entered or uploaded from MOLKICK. The system uses the ROSDAL string to identify the created set. 

QS < > ID=< > QS ID=amines QS T ID=search1 QS F ID searchl QS R 1500 ID=Smith2 Any QS command can be identified in the system response by adding a name after the ID. The QS command with its options and set identifier can have a maximum of 240 characters. If the ID= feature is not used, the system uses the ROSDAL string as the set Identifier. 

It has been shown how the ROSDAL syntax allows for the representation of general inorganic compounds. As already mentioned, it is based on connection tables for structured compounds. Its basic construction is adapted to the multi-component systems which make inorganic compounds more involved than organic compounds and the substance and component attributes enable us to encode inorganic structure tables for substances for which no structure can be drawn. 

The Structure Distribution File format is another means for representing inorganic compounds on a computer system. With the Gmelin Database it is used as the intrinsic storage format for substance and structure information. The SDF format has been developed to store the same amount of information as is contained in a ROSDAL string, but there is no one-to-one correspondence between different constructs of the ROSDAL specification and of the SDF format. 

Various line notations have been devised to depict accurately both the atomic content and the orientation of the compound. Much of the focus in creating notation systems has been geared toward computer input and manipulation of structures. Some of the well-known notations include Wiswes.ser (WLN), Dyson-IUPAC, Hayward, Skolnik, Gremas and more recently also SMILES, and ROSDAL. All of these systems require a detailed memorization of their rules and conventions and are limited strictly to the audience familiar with those rules. 

Another linear notation is the ROSDAL coding. It has very elaborate stereochemical syntax elements, which make it useful for the definition of organic as well as inorganic compounds. It covers even conformation representations. ROSDAL strings are extensively used in the Beilstein XFIRE system. 

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