It is not possible, because the AD uses its own database, so the information is concentrated on that basis. However, it is possible to do the reverse. Just create an application to adapt your applications to Single Sign On, that is, all login screens of your application, will be directed to a specific application and that application, will authenticate to AD.
Unfortunately, Active Directory can not use an outsourced database. That way, you will not be able to configure it to use your own.
Looking quickly, Active Directory has some things that programs can use to interact with AD. The Active Directory Service Interfaces (in English) would be a possible solution to connect your data and put it inside the AD to use it