compiling problem

I'm new in linux world, and i have the following problem when I execute
./configure :

...
checking for bind_textdomain_codeset... yes
checking for msgfmt... no
checking for pkg-config... /usr/bin/pkg-config
checking for   libxml-2.0 >= 2.0.0        libxslt >= 1.0.0
libgnomeui-2.0 > 2.0.0      libglade-2.0 >= 2.0.0... Package libxml-2.0
was not found in the pkg-config search path.
Perhaps you should add the directory containing `libxml-2.0.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libxml-2.0' found

configure: error: Library requirements (  libxml-2.0 >= 2.0.0     libxslt
>= 1.0.0  libgnomeui-2.0 > 2.0.0      libglade-2.0 >= 2.0.0) not met;
consider adjusting the PKG_CONFIG_PATH environment variable if your
libraries are in a nonstandard prefix so pkg-config can find them.


The system is an redhat 7.3 with ximian desktop 2. (GNOME 2.2.2)
More info:
# rpm -qa|grep libxml
libxml2-2.5.7-0.ximian.4.2
perl-libxml-enno-1.02-15
libxml-1.8.17-3.ximian.4.7
libxml2-python-2.5.7-0.ximian.4.2
perl-libxml-perl-0.07-14

What can i do?

Thanks a lot!!

Edgard Pineda.