macOS Problem with compilation matlab-json

[3835]

Hi Everyone!
I want to compile matlab_json (compile in Matlab) but I have problem with pkg_config. When I use make command in Matlab I get this error:

Error using mex
/Users/3835/Documents/MATLAB/matlab-json-master/Package json-c was not found in the pkg-config search path.
Perhaps you should add the directory containing `json-c.pc'
to the PKG_CONFIG_PATH environment variable
No package 'json-c' found
 not found; check that you are in the correct current folder, and check the spelling of
 '/Users/3835/Documents/MATLAB/matlab-json-master/Package json-c was not found in the pkg-config search path.
Perhaps you should add the directory containing `json-c.pc'
to the PKG_CONFIG_PATH environment variable
No package 'json-c' found
'.

Error in make (line 8)
    mex(flags, '-ljson-c', '-g', 'fromjson.c');

json-c package is required and I installed it before from source.

I check PKG_CONFIG_PATH, this is result:

MacBook:~ 3835$ echo $PKG_CONFIG_PATH
/usr/local/lib/pkgconfig:/usr/local/lib

MacBook:~ 3835$ pkg-config --cflags json-c
-I/usr/local/include/json-c

MacBook:~ 3835$ pkg-config json-c --cflags
-I/usr/local/include/json-c

Locate command for json-c

/opt/local/include/json-c
/opt/local/include/json-c/arraylist.h
/opt/local/include/json-c/bits.h
/opt/local/include/json-c/debug.h
/opt/local/include/json-c/json.h
/opt/local/include/json-c/json_c_version.h
/opt/local/include/json-c/json_config.h
/opt/local/include/json-c/json_inttypes.h
/opt/local/include/json-c/json_object.h
/opt/local/include/json-c/json_object_iterator.h
/opt/local/include/json-c/json_object_private.h
/opt/local/include/json-c/json_tokener.h
/opt/local/include/json-c/json_util.h
/opt/local/include/json-c/linkhash.h
/opt/local/include/json-c/printbuf.h
/opt/local/include/json-c/random_seed.h
/opt/local/lib/libjson-c.2.dylib
/opt/local/lib/libjson-c.a
/opt/local/lib/libjson-c.dylib
/opt/local/lib/pkgconfig/json-c.pc
/opt/local/var/macports/registry/portfiles/json-c-0.12-20140410_0
/opt/local/var/macports/registry/portfiles/json-c-0.12-20140410_0/aafa63c7067e0bf756c8a57ced9678aabb26fdec34e5807554442436238c1987-986
/opt/local/var/macports/registry/portfiles/json-c-0.12-20140410_0/aafa63c7067e0bf756c8a57ced9678aabb26fdec34e5807554442436238c1987-986/Portfile
/opt/local/var/macports/software/json-c
/opt/local/var/macports/software/json-c/json-c-0.12-20140410_0.darwin_14.x86_64.tbz2
/opt/local/var/macports/sources/rsync.macports.org/release/tarballs/ports/textproc/json-c
/opt/local/var/macports/sources/rsync.macports.org/release/tarballs/ports/textproc/json-c/Portfile
/usr/local/Library/Formula/json-c.rb
/usr/local/include/json-c
/usr/local/include/json-c/arraylist.h
/usr/local/include/json-c/bits.h
/usr/local/include/json-c/debug.h
/usr/local/include/json-c/json.h
/usr/local/include/json-c/json_c_version.h
/usr/local/include/json-c/json_config.h
/usr/local/include/json-c/json_inttypes.h
/usr/local/include/json-c/json_object.h
/usr/local/include/json-c/json_object_iterator.h
/usr/local/include/json-c/json_object_private.h
/usr/local/include/json-c/json_tokener.h
/usr/local/include/json-c/json_util.h
/usr/local/include/json-c/linkhash.h
/usr/local/include/json-c/printbuf.h
/usr/local/include/json-c/random_seed.h
/usr/local/lib/libjson-c.2.dylib
/usr/local/lib/libjson-c.a
/usr/local/lib/libjson-c.dylib
/usr/local/lib/libjson-c.la
/usr/local/lib/pkgconfig/json-c.pc

What could be wrong?
I use OS X 10.10.1 and Matlab R2014a.