$pattern = '~(([a-z A-Z]),|\\;)~';
$subject = 'ali, veli (49, 50, abc); hepsi, deli; meli';
$limit = -1;
$flags = PREG_SPLIT_NO_EMPTY;
$result = preg_split ($pattern, $subject, $limit, $flags);

array (
  0 => 'ali',
  1 => ' veli (49, 50, abc)',
  2 => ' hepsi',
  3 => ' deli',
  4 => ' meli',
);