use strict;
use XML::Rules;

my $parser = XML::Rules->new(
	start_rules => [
		'PC-InfoData_urn,PC-Compound_atoms' => 'skip',
	],
	rules => [
		_default => 'as is',
		'PC-CompoundType_id_cid,PC-InfoData_value_binary' => 'content',
		'PC-InfoData' => sub {
			return unless $_[1]->{'PC-InfoData_value'}{'PC-InfoData_value_binary'};
			return '@InfoData' => $_[1]->{'PC-InfoData_value'}{'PC-InfoData_value_binary'};
		},
		'PC-Compound' => sub {
			my $id = $_[1]->{'PC-Compound_id'}{'PC-CompoundType'}{'PC-CompoundType_id'}{'PC-CompoundType_id_cid'}
				or return; # no ID found
			my $data = $_[1]->{'PC-Compound_props'}{'InfoData'}
				or return; # no data
			return $id => $data;
		},
		'PC-Compounds' => 'pass',
	],
	stripspaces => 7,
);

my $data = $parser->parse(\*DATA);

use Data::Dumper;
print Dumper($data);


__DATA__
<PC-Compounds>
<PC-Compound>
    <PC-Compound_id>
      <PC-CompoundType>
        <PC-CompoundType_id>
          <PC-CompoundType_id_cid>1</PC-CompoundType_id_cid>
        </PC-CompoundType_id>
      </PC-CompoundType>
    </PC-Compound_id>
    <PC-Compound_atoms>
    </PC-Compound_atoms>
    <PC-Compound_props>
      <PC-InfoData>
      </PC-InfoData>

      <PC-InfoData>
        <PC-InfoData_urn>
          <PC-Urn>
          </PC-Urn>
        </PC-InfoData_urn>
        <PC-InfoData_value>
          <PC-InfoData_value_binary>00000371E07238000000000000000000000000000000
+00000000000000000000000000000000001E00000000000814E1800602080300040008000090080
+0000000000000000001080000020014008000070000052000100000240000000000000000000000
+0000000000000000000000000000</PC-InfoData_value_binary>
        </PC-InfoData_value>
      </PC-InfoData>

      <PC-InfoData>
      </PC-InfoData>
    </PC-Compound_props>
  </PC-Compound>
</PC-Compounds>