<span class="spann1">СТАТЬИ:</span>
alert( 'jddddd\nddddddddddddddddddddddddncnnccjjcjjfhfhhhfhfhfh100 <span class="spann1">СТАТЬИ:</span>jffffffffffffffffffffffffff' .match(/[\s\S]*(?=<span class="spann1">СТАТЬИ:<\/span>)/)[0] )