T63-2022 Notification regarding BIOVIA Direct 2022 SP1 HF1

DIR-4254

Direct now takes into account enhanced stereochemistry in the perception of meso symmetry. Molecules that would have been classified as meso are no longer perceived as meso if they have enhanced stereochemistry. This change has implications for Flexmatch searches, including exact match,  that take into account stereo, as molecules with enhanced stereo that were perceived as meso before are now considered chiral and might not match similar molecules with different stereo.

DIR-4251

Fixed a problem with the perception of aromaticity of six-membered rings containing atoms such as sulfur or phosphorus with alternating single and double bonds. In previous releases, the perceived aromaticity could depend on the positioning of the double bonds. Now, the aromaticity is perceived identically, regardless of the double bond positions. A previous fix in the 2019 release resolved the issue only partially.