<?php
 
$string = "<img class=\"img-responsive\" src=\"http://localhost/example-local/sites/example/files/styles/thumbnail/public/news-story/gallery-images/Desert.jpg?itok=bqyr-vpK\" width=\"100\" height=\"75\" alt=\"\" /><blockquote class=\"image-field-caption\">\r\n  <p>Desert</p>\n</blockquote>\r\n";
 
preg_match('~src=\\"(.*?)\\"~i', $string, $matches);
print $matches[1];
 
print "\n\n";
 
print preg_replace('~.*?src=\\"(.*?)\\".*~is', '$1', $string);

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