$re = '/(<meta property="og:image" content=")(.+?)(?:)">"/m';
$str = '<meta property="og:image" content="https://m.media-amazon.com/images/M/MV5BYWFlZGY2NDktY2ZjOS00ZWNkLTg0ZDAtZDY4MTM1ODU4ZjljXkEyXkFqcGdeQXVyMjUzOTY1NTc@._V1_UY1200_CR79,0,630,1200_AL_.jpg">"';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php