<?php
$text = '<a href="link">
<font style="font-size: 14px;" color="black" face="arial"><b>String que eu quero pegar</b></font>
</a>
';
PD9waHAKJHRleHQgPSAnPGEgaHJlZj0ibGluayI+CiAgPGZvbnQgc3R5bGU9ImZvbnQtc2l6ZTogMTRweDsiIGNvbG9yPSJibGFjayIgZmFjZT0iYXJpYWwiPjxiPlN0cmluZyBxdWUgZXUgcXVlcm8gcGVnYXI8L2I+PC9mb250Pgo8L2E+Cic7CmVjaG8gc3RyaXBfdGFncygkdGV4dCk7