T78-2020 BIOVIA Direct 2020: Potential change of search results for allenes and atropisomers

Program

BIOVIA Direct 2020

Operating System

All supported

Background

BIOVIA Direct supports stereo bonds at allenes and atropisomers to define particular stereo configurations. The perception of such stereo bonds in BIOVIA Direct searches has changed with BIOVIA Direct 2020, and users of Direct 2020 and later might therefore see different results from queries that include allenes and atropisomers with stereo bonds.

Solution

In the following, ‘structures’ refers to molecules and reactions that constitute or include allenes or atropisomers. The perception of tetrahedral stereochemistry in structures and reactions in BIOVIA Direct searches did not change and is not part of this Technote.

In BIOVIA Direct versions 2019 or earlier, stereo bonds at allenes or atropisomers were interpreted as absolute, regardless of whether they were actually absolute or part of an AND or OR stereo group. Accordingly, such structures did match in a substructure or exact match query, provided that the stereo bond types (up/down) were matching. For instance, queries with ABS stereo configuration hit registered structures with AND stereo configuration.

Starting with the release 2020, BIOVIA Direct now considers chiral flags and stereo collections at allenes and atropisomers. Consequently, queries including allenes or atropisomers might give different search results, depending on how such structures were registered into the database. For instance, structures that were registered with AND stereo configuration do now no longer match a query structure that includes an ABS stereo configuration.

In general, the results of such queries are now more accurate in BIOVIA Direct 2020 and higher. If the search results in BIOVIA Direct 2020 and later do not meet your expectations, you should consider checking the registered structures to see if they were registered with the intended stereo configuration. If the stereo configuration turns out to not be as intended these particular structures should be reregistered with the intended stereo configuration. Likewise, users that draw queries including allenes and atropisomers with stereo bonds should make sure that they draw the stereo configuration as intended.

How to contact BIOVIA Support

If you have any questions, please contact BIOVIA Support.