The wptexturize function is responsible for some automatic text transformations in WordPress, for instance, it changes straight quotes ( ' or " ) to curly quotes (also known as "smart quotes").
In WordPress 4.0+, you can turn off wptexturize by using the
run_wptexturize filter. Passing false to the filter will tell WordPress to skip running
Simply add the following code to your theme's functions.php file to disable wptexturize globally.
/* Disable wptexturize */ add_filter( 'run_wptexturize', '__return_false' );