my $regex_notiz = decode("UTF-8",'[^a-z!/()=?_üäöß:.,\-+ \d$%]');
my $text = decode("UTF-8",'!"§$%&/()=?_und überhaupt:;,GROßÖÄÜß.+und ziffern 0123456789-und kleinöäüß%$');
$text =~ s/$regex_notiz//ig;
print "neu: >$text<\n";

Wide character in print at regex.pl line 15 (#1)
    (W utf8) Perl met a wide character (>255) when it wasn't expecting
    one.  This warning is by default on for I/O (like print).  The easiest
    way to quiet this warning is simply to add the :utf8 layer to the
    output, e.g. binmode STDOUT, ':utf8'.  Another way to turn off the
    warning is to add no warnings 'utf8'; but that is often closer to
    cheating.  In general, you are supposed to explicitly mark the
    filehandle with an encoding, see open and perlfunc/binmode.

neu: >!´┐¢$%/()=?_und ´┐¢berhaupt:,GRO´┐¢´┐¢´┐¢´┐¢´┐¢.+und ziffern 0123456789-und klein´┐¢´┐¢´┐¢´┐¢%$<