Organic chemicals informed systems

Physical means of information are found with all living organisms. Chemical signaling is typical ofthe lower organisms and, through the vomeronasal neurons, the animals (Leinders-Zufall 2000). The latter rely also on sound and colors as information systems. Sound is flatly repetitive, such as with birds, to avoid breeding between closely related species. With man (MacNeilage 2000), and perhaps also apes and dolphins (Nowak 2000), soimd is syntactic. Man seems to have also inherited a rudimentary chemical information system, that is, sexual attraction exerted by pheromones released fi om the armpits (Stem 1998). However, the claim remains to be fiilly substantiated. 

All atoms were drawn with whatever atom symbol had last been selected. To select an atom symbol the user touched the LABEL ATOM menu item, which caused a secondary menu of atom symbols to appear at the bottom of the screen in the message area previously reserved. The list was chosen by frequency of appearance in organic compounds as determined by an examination of compounds in the Structure and Nomenclature Search System (a component of The Chemical Information System). Similarly, bonds were drawn using the last selected bond type. 

The characterization of a chemical compound by a unique canonical code in a chemical information system has to take into account that a large fraction of organic compounds have several representations which are chemically equivalent but structurally distinct. The problem arises in compounds containing aromatic systems whose system of alternating single and double bonds can be represented in more than one way. For example, the aromatic system of pyridazine can be represented by the following two structures (11) and (12) ... 

In a new version of SECS, a transform library of 1291 basic reactions was extracted from a database of 14994 reactions. Indeed, in databases, numerous reactions are stored several times under different structural environments. For example, reduction of a ketone to an alcohol was present 78 times in the precedent one. The SPEK program uses transforms library from a database of 300(X) reactions. Blurock developed a system to extract, calculate, and organize chemical information from chemical databases. ... 

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