use strict;
use XML::Simple;

my @list; #read in your list into this array
my $infile ; #name of the file of your original xml
my $outfile; # name of the output file

my $parser = XML::Simple->new(rootname=>"bulk-load",noattr=>1,keyattr=>['ISSN']);
my $xml = $parser->XMLin($infile);
foreach my $issn (@list){
	delete $xml->{journal}->{$issn};
}
$parser->XMLout($xml,outputfile=>$outfile);