concatenating a function and a string

I have this statically:

define( 'PLUGIN_BASENAME', 'new-plugin/new-plugin.php' );

And get_option('plmn-plugin-field') will give a dynamic name. e.g. if it gives abcd, this should be:

 define( 'PLUGIN_BASENAME', 'abcd/abcd.php' );

And this is not working:

 define( 'PLUGIN_BASENAME', 'get_option('plmn-plugin-field')/get_option('plmn-plugin-field').php' );

How can i make it working?